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CatalogⅠ IntroductionⅡ What is an LR41 Battery?Ⅲ Applications of LR41 BatteryⅣ LR41 Battery SpecificationsⅤ Capacity and Voltage of LR41 BatteryⅥ LR41 Battery ChemistryⅦ How to Install LR41 Batteries in Your DevicesⅧ What is the Equivalent to an LR41 Battery?8.1 Alkaline8.2 Silver-OxideⅨ LR41 VS. SR41Ⅹ Frequently Asked Questions About LR41 Battery Ⅰ IntroductionThe LR41 battery is a button-type power cell that is well-known for its use in pocket calculators and timepieces. This small power cell uses alkaline battery chemistry, popularly known as a button battery. This alkaline battery, on the other hand, is similar enough to silver oxide batteries to be interchangeable. The LR41 coin cell battery has a nominal voltage of 1.55 volts and a dimension of 3.6 mm x 7.9 mm. If you require an LR41 battery replacement and it is unavailable, there are other alternatives available on the market. What is the LR41 battery equivalent? There are a plethora of battery replacements available nowadays if you're seeking for an LR41 replacement. Batteries  that are nearly the same size and specifications. These batteries are thought to be interchangeable with the LR41 button-type battery. Ⅱ What is an LR41 Battery?The LR41 Battery  is a tiny, alkaline button cell battery. The LR41 is a relatively common battery that is manufactured by many prominent brands including Toshiba, Maxell, and others. The LR41 battery is also extensively manufactured by smaller corporations and private label battery manufacturers, such as Tianqiu. Other firms, like as Energizer, make batteries that are identical in size to the LR41 but have a different composition, such as silver oxide. Ⅲ Applications of LR41 BatteryLR41 batteries are widely utilized in a wide range of applications. They are only used in compact, portable electronic devices with low power consumption. Clocks, watches, laser pointers, thermometers, glucometers, voice recorders, heart rate monitors, cholesterol testing, and toys are examples of these gadgets. These are only a few  of the most frequent devices for which an LR41 battery is used. It will take us a day to list all of them if we list them all. Typically, devices will indicate on the user's manual that they are powered by such a battery, and checking it is one way to ensure that the LR41 battery is suitable for the device.  Ⅳ LR41 Battery SpecificationsLR41 Battery Nominal Voltage1.50 VoltsCapacity≈  25-32mAhOperating Temperature0°C – 60°C Diameter7.9mmHeight3.6mmChemistryAlkaline (similarly sized variants in silver oxide) Ⅴ Capacity and Voltage of LR41 BatteryWhen it comes to selecting the correct battery for an application, the capacity and voltage rating are the two most important specifications to consider. This is because the voltage rating of the battery will tell you how powerful the cell is and its electrical potential. The capacity of the battery, on the other hand, will offer you an estimate of how long the battery will be able to power gadgets. Battery capacity also indicates how much current a cell can deliver over a given time span. The LR41 coin cell battery is designed with a nominal voltage of 1.5 volts. If the battery is brand new, the voltage rating can rise to between 1.55 and 1.62 volts. Its capacity is normally in the range of 25 mAh to 32 mAh. This is the packaging for ordinary alkaline batteries. The capacity of silver oxide LR41 cells, on the other hand, ranges between 38 and 45 mAh. Ⅵ LR41 Battery ChemistryThe alkaline power cell chemistry is used in LR41 batteries. They are, nevertheless, designed to be almost identical to silver oxide coin-type batteries, making them interchangeable with their silver oxide equivalents. When it comes to many applications, the difference between alkaline and silver oxide cells is negligible; nonetheless, silver oxide cells have a higher capacity, making them more appealing. Helpful Hint: When purchasing LR41 power cells, check for those that have a "zero percent Hg" label. This signifies that the battery is free of mercury, which makes it safer if the battery leaks. Ⅶ How to Install LR41 Batteries in Your DevicesDetermine the positive and negative ends of the battery first. The flat side (sometimes with markings) of a common Alkaline LR41 battery is normally the positive side. A little round protrusion should be evident on the opposite side. Typically, the side is the negative end. You can easily align the positive and negative ends of the battery with the relevant markings on your device now that you've determined the positive and negative ends of the battery. Please keep in mind that certain gadgets feature small metallic tabs to help with battery retention and function. It is critical that these tabs remain unharmed and undamaged, as doing so may jeopardize the performance of your device. If you happen to move this tab slightly out of place, you can generally fix it by gently readjusting it back into the proper alignment. Ⅷ What is the Equivalent to an LR41 Battery?If the LR41 battery is unavailable, the AG3 coin cell battery is the best alternative. It is regarded as the best power cell comparable to the LR41 button-type battery. There are more LR41 replacements available, and they are all interchangeable with the button-type battery. Some of the alternatives include CX42 cells, LR736, V3GA, V36A, GP192, G3, 92A, 384, 192, 392A, 392, SR41SW, SR41, and L736F. All of these power cells are considered equivalent cells of the LR41 coin cell battery,  and their specifications are nearly identical, allowing them to be interchanged. So, if you need a replacement battery for a dead LR41 but can't find one, try for the batteries listed above. This will keep your device operational and allow you to get it back up and running quickly. 8.1 AlkalineThe alkaline alternatives are the most similar to the LR41 in terms of specifications, with the same voltage, mAh, and chemistry. One significant advantage of alkaline technology is its low cost, with this sort of battery costing only a few dollars. When looking for equivalent batteries, keep the following in mind:V36ALR736L736AG3192RW87SB-B1V3GA 8.2 Silver-OxideA silver-oxide LR41 battery is quite similar to a conventional alkaline battery. The voltage is often 1.55 V, which is only slightly higher, but the capacity is generally increased. Whereas alkaline LR41s typically provide between 25 and 45 mAh, silver-oxide versions often provide 38 – 45 mAh. The fact that silver-oxide chemistry retains a steady voltage output as it degrades is a huge advantage. This is important in applications that rely on the voltage of the battery, such as wristwatches and digital thermometers. Silver-oxide batteries will also outlast alkaline batteries. Modern silver-oxide batteries are often multi-drain capable. SR41 style batteries were either low-current or high-current in the past, and it was critical to select the correct one for your device. Multi-drain batteries can produce both low and high currents. When looking for silver-oxide LR41 counterparts, keep the following battery types in mind: SR41SR41WSR736SG3392384D392V392 (547)SB-B1 The 3 Most Common Silver Oxide Equivalent of LR41As previously stated, the LR41 button-type battery has numerous alternatives. Silver oxide counterparts, on the other hand, are preferred due to the additional capacity they provide. Here is a list of the top three LR41 silver oxide alternatives to learn more about. These are your best options for a coin-type battery that has a higher capacity than the LR41. 1. The SR41W Button-Type Power CellThe SR41W coin-type battery is a good silver oxide battery equal to the LR41. This battery is the same size as the previous one, measuring 7.9 mm × 3.6 mm and weighing 0.67 grams. It operates at temperatures ranging from -10 degrees Celsius to 60 degrees Celsius. The SR41W battery is designed with a nominal voltage rating of 1.55 volts and a nominal battery capacity of approximately 45 mAh. As you can see, this coin-type battery has a higher capacity than the LR41, which means it will last longer. It can power devices for a longer period of time because to its ability to store more energy. 2. The 384 Button-Type Power CellAnother excellent silver oxide option for the LR41 cell is the 384 button-type battery. It has a 7.9 mm diameter and a 3.6 mm height as well, but it is often heavier, weighing 1.14 grams. This battery has the same nominal voltage and capacity rating as the first one, with 1.55 volts and 45 mAh, respectively. This LR41 silver oxide alternative is supposed to have a three-year lifespan, making it a more appealing option. 3. The 392 Button-Type Power CellThe 392 coin-type battery is my third pick for the best silver oxide LR41 battery alternative. This battery weighs 0.32 oz and has the same measurements of 7.9 mm x 3.6 mm. It also has a nominal voltage rating of 1.55 volts and a battery capacity value of 45 mAh. If the LR41 is not available, this is another excellent option due to its capacity to store more power and last longer. Furthermore, the LR code indicates the type of chemistry employed inside the battery, which is lithium in this case. Obviously, a battery that is equivalent to the LR41 must be of comparable size and voltage, but what about the chemistry and mAh ratings? Let's have a look at the chemistry-based options. Details on LR41 comparable replacement batteries may be found in the table below. LR41 Battery Equivalent ChartAlkalineTop ManufacturersCapacity (mAh)VoltageSupported DevicesLR41Murata, Maxell-251.5VWatch,calculator,electronic toy, calliperV36ARenata, Varta, Rayovac ,Panasonic-26LR736ETC, everActive-31L736Exell, Vinnic-45AG3Energizer, Panasonic, Renata-35192GP, Sony35-32V3GAVarta Silver OxideTop ManufacturersCapacity (mAh)VoltageSupported Devices384Energizer, Maxell-441.55VSensitive devices: wristwatch,digital thermometerSR41Murata45SR41WMaxell39SR41SWSeiko45SR736Cellectron45SG3Generic 392Energizer, Rayovac, Renata D392Duracell45V392(547)Varta SB-B1Seiko Zinc AirTop ManufacturersCapacity (mAh)VoltageSupported Devices312Duracell, Rayovac170-1801.45VHearing aidsPR41Duracell, Rayovac160-175P312Powermax170ZA312Renata175 Ⅸ LR41 VS. SR41The SR41 and LR41 batteries are small button/coin cell batteries that are commonly found in digital thermometers, wrist watches, toys, small LED flashlights, wearable electronics, remote controls, and other similar devices. These batteries are available on the market in a variety of chemistries, with comparable but not identical discharge characteristics, and are frequently labeled differently by their makers, leading to some user confusion. The physical dimensions of the SR41 and LR41 batteries are (D x H) 7.9 x 3.6 mm (0.311 × 0.142 inches), and their common properties are listed in the comparison chart below: ChemistryAlkalineSilver-OxideZinc AirNominal Voltage1.5V1.55V1.4 - 1.45VCutoff Voltage1.0V1.2V1.1VNotesVoltage drops over timeVery constant voltageSlightly lower voltage, large capacity;mostly used as hearing aid batteriesTypical LabelsLR41, LR736, AG3SR41, SR736, SR736PW, SR736SW, SG3, AG3, 192, 384, 392312, ZA312, Brown Tab, PR41, 7002ZDTypical Capacity25-32 (45) mAh38-45 mAh~180 mAh The real capacity of these batteries is determined by the device's cutoff voltage, but it is also determined by the drain current - the higher the current, the lower the final capacity. Alkaline 7.9 x 3.6 mm batteries: The most frequent label for an alkaline 7.9 x 3.6 mm battery is LR41, however other labels, such as LR736, AG3, and similar, are also used. Fortunately, most respectable brands always include LR41 on the battery label, allowing users to quickly identify the battery type and model. The LR41 battery has a nominal voltage of 1.5 volts and a capacity of 25-32 mAh. Some brands advertise significantly higher capacities for their LR41 batteries, but these batteries are frequently exhausted using ultra-low currents, with actual capacities commonly falling within the 25-32 mAh range. The cutoff voltage of the LR41 battery is determined on the cutoff voltage of the device being powered, however it is often around 1.0 volts, while many basic devices can operate at 0.8 volts per battery. Note: LR41 batteries are widely used, for example, as digital thermometer batteries. If the thermometer displays 'LO' or 'LOW,' it signifies that the measured temperature is below a specified threshold, not that the battery is (nearly) dead - always check the thermometer's instructions for confirmation! The shelf life of LR41 batteries varies depending on storage temperature and manufacturer, however if the batteries are stored at or below 68-77°F (20-25°C), the estimated shelf life is at least 2-3 years. Silver-oxide 7.9 x 3.6 mm batteries: The SR41 battery is the most frequent label for silver-oxide 7.9 x 3.6 mm batteries, while other labels such as SR736, SR736PW, SR736SW, SG3, AG3, 192, 384, 392, and similar are also used. The nominal voltage of the SR41 battery is 1.55 volts,  and the nominal capacity is 38-45 mAh. Silver-oxide batteries provide a more steady output voltage than alkaline batteries, making them a better alternative for powering more sensitive devices like wrist watches and similar. The cutoff voltage of the SR41 battery is also dependent on the cutoff voltage of the device being powered, but it is usually around 1.2 volts - when the voltage of the silver-oxide battery falls below 1.25 volts, and especially below 1.2 volts, it begins to decline fast. Silver-oxide SR41 batteries were frequently built in low-drain and high-drain configurations, with low-drain SR41 batteries intended for watches and similar devices that operate continuously at very low currents and high-drain SR41 batteries intended for devices that require relatively high currents on a regular basis. With technological advancements, most current SR41 batteries are constructed as multi-drain batteries. For example, the Energizer 392/384 battery (external link, PDF datasheet) has a nominal voltage of 1.55 volts and a typical capacity of 44 mAh when drained down to 1.2 volts using a 22 k load at 21°C. Silver-oxide SR41 batteries have a longer shelf life than alkaline LR41 batteries; when stored at 68°F (20°C), a good SR41 battery has an expected shelf life of 6-8 years, occasionally even more. Ⅹ Frequently Asked Questions About LR41 Battery1. What battery is equivalent to an LR41?Direct equivalents for LR41 include 192, 92A, LR736, and AG3. The only difference between these batteries and the LR41 battery is their nomenclature. 2. Are LR41 and 392 batteries the same?This 392 Silver Oxide Button Cell Battery has a capacity of 45 mAh and a voltage of 1.55 V. It is also known as an LR41 battery. These are watch batteries and small electronic battery replacements. 3. Can I use LR44 battery instead of LR41?The size, voltage, and weight of LR43, LR41, and LR44 batteries differ. As a result, they are not completely interchangeable. 4. What size is LR41?7.9 x 3.6 mm1.5 Volt Maxell LR41 (192, AG3) Alkaline Button Cell 7.9 x 3.6 mm in size. Electronic clocks, watches, calculators, computers, cameras, digital cameras, thermometers, digital voice recorders, glucometers, cholesterol testing meters, and toys all make use of this material. 5. Is AG13 same as LR41?Other names for the AG3 coin cell battery include: 384, 392 192, LR41, LR736 L736 GP192, and V36A. Available in packs of 10, 30, 50, 100, and more! We don't have a wholesale order of AG3 coin cells that is too huge for us. 6. Is it possible to recharge LR41 batteries?20 x 1.5V Cell Batteries are included in the bundle; Model: LR41; Type: Lithium Battery (Non-rechargeable); Voltage: 1.5 Volts. 7. What does an LR41 battery look like?Because the battery is a circular disc-shaped cell, its dimensions can be represented as a diameter (the distance from one edge of the circle to the opposite edge, passing through the center) and the battery's height. From top to bottom, an LR41 battery has a diameter of 7.9 mm (5/16′′) and a height of 3.6 mm (9/64′′). 8. What is the purpose of an LR41 battery?These tiny alkaline button batteries are commonly used in miniature electronic gadgets including laser pointers, single-function clocks, interactive children's books, and medical testing devices. They are typically employed in series to boost the performance of these applications. 9. How are LR41 batteries installed?Typically, the chamber is spherical and constructed of plastic, with metal connectors on the interior. The battery should be able to be inserted directly into the space, though in certain cases, putting one edge first, with the battery tilted diagonally, and then swinging the battery down into the rest of the compartment is easier. 10. Are LR41 and 312 batteries interchangeable?Other LR41 battery labels include LR736, AG3, and others — some LR41 battery labels are also used for SR41 batteries and vice versa. The 312 battery has a little lower voltage of 1.40-1.45 volts, but a substantially larger capacity, often approximately 160 mAh. 11. What’s the distinction between LR41 and SR41?As you are aware, the LR41 has a voltage of 1.5v, however the SR41 has a voltage of 1.55v regardless of how new it is. As a result, the SR41 can provide more power to small devices, allowing them to run for longer periods of time. The SR41 has a 45mAh capacity, allowing it to deliver more current than most. 

CatalogⅠ What is a CR2016 Battery?Ⅱ CR2016 SpecificationsⅢ Applications of CR2016 BatteryⅣ Benefits of CR2016 Battery4.1 Excellent Discharge Characteristics4.2 Long-Term Reliability4.3 High Energy Density4.4 Many Of UseⅤ How to Replace a CR2016 BatteryⅥ Things To Consider When Buying CR2016 Battery6.1 Maintenance6.2 Battery Size6.3 Cranking Voltage6.4 Battery Freshness6.5 Reserve CapacityⅦ CR2016 vs. CR2025 vs. CR20327.1 CR2016 vs. CR2025 vs. CR2032: What are the Similarities?7.2 CR2016 vs. CR2025 vs. CR2032: What are the Differences?7.3 CR2016 vs. CR2025 vs. CR2032: Are These Batteries Interchangeable?Ⅷ CR2016 Battery EquivalentsⅨ Using WarningⅩ Frequently Asked Questions About CR2016 Ⅰ What is a CR2016 Battery?The CR2016 lithium coin cell is a primary lithium battery with a voltage of 3V. The CR2016 lithium coin cell is a 3V Lithium battery with a long shelf life for backup energy, great temperature resistance, and superior storage capacity. This lithium coin cell  battery has a high energy density, durability, and stability, as well as a long battery life in a variety of applications. CR2016 Battery Replacement Ⅱ CR2016 Specifications   When selecting a CR2016 tablet battery, consider its parameters and technical requirements. Everything will become much clearer once you realize that the first two numbers in the numerical identification (in the instance of the model in issue, they are 20) are an indication of the battery's diameter in millimeters. The other two numbers (16) are quite large. As a result, CR2016 includes:diameter of 20 millimeters6 mm thick If the customer is unsure what size battery he requires, this information can be found on the device for which the battery is intended. It is usually stated on the reverse side or in the instruction manual. The new variants have the same rated voltage of 3 volts. The power can vary, but the average is 75 mA each hour. The weight ranges between 1.6 and 1.9 grams. The greater the weight, the longer the service life. The output current is rated at 0.4 mA. The chemical element of lilies is indicated by the characteristic CR. Lithium batteries can be stored for around ten years without losing their functionality. However, with active use, the service life is around two years. ParameterValueBasic designation2016ViewLithium ionCapacity90 mAhVoltage3 vANSI / NEDA5000LCThe formcoin or tabletHeight1.6 mmDiameter20 mm Ⅲ Applications of CR2016 Battery CR2016 power supplies have demonstrated their worth and are used more frequently than other power supplies with similar dimensions. WatchesCalculatorsPC notebooksElectronic keysCard-type radiosIC cardsMemory cardsMedical equipmentCMOS memory backups Buyers appreciate this model because of its great power and energy consumption, as well as its long service life. At the same time, every manufacturer strives to produce batteries with the best technical qualities. Ⅳ Benefits of CR2016 BatteryThe CR2016 battery is a 1.4 volt button cell manufactured by companies such as 3M and Panasonic Chemical Comp. Wristwatches, calculators, and keyless auto remotes all use the CR2016 battery. Because of its small size and low cost, the CR2016 battery offers numerous advantages to consumers. The battery is small enough to be portable and does not require a lot of electricity or electric current to supply enough power for use in small electronic devices like wristwatches and calculators. The CR2016 battery is extremely compact. This makes it ideal for devices that are compact, have limited space, or are intended to fit in places with restricted space. The CR2016 battery is also fairly inexpensive while yet providing adequate power. This implies that, while the battery may not last as long as some larger batteries, it will also be less expensive. The main advantage of a cr2016 battery is that it charges quickly and consistently. The battery will supply the circuit with a consistent voltage. It will outperform a cr2032 battery. 4.1 Excellent Discharge CharacteristicsIt is not essential to discharge the battery before recharging it with this battery. This is why it has such a good discharge property. It can also be utilized for a wide range of functions and under a variety of conditions, which explains its varied discharge characteristic. This battery's principal application is for digital gadgets, but it may also be used in a variety of other ways and has a wide range of applications. This is a Lithium Ion Battery, which is often found in cell phones, laptop computers, digital cameras, and video recorders. The battery has a high energy density and outstanding discharge characteristics. 4.2 Long-Term Reliability  The long-term reliability of the Cr2016 battery is an important concern. The frequency of use and the voltage regulator employed determine the requirement for replacement. The use of a voltage regulator will extend the battery's life. Since of its lower dropout voltage, a transistor type (voltage regulator) is recommended over a Zener diode type because it decreases stress on the battery. Because of the relatively high cell voltage, the conventional lithium-manganese dioxide chemistry has inherent stress (nominal 3.0V). A typical Zener diode regulator will drop the voltage to 2.4 volts (30 percent less usable energy), further stressing an already stressed battery. The transistor type regulates down to roughly 2.7V, minimizing battery stress and extending battery life. The Cr2016 battery is a lithium ion battery designed to give longer power to electrical gadgets. The battery also employs a new electrolyte composition, which results in more stable capacity with less degradation over time. This is what gives the battery a higher long-term reliability over time. 4.3 High Energy Density  The CR2016 battery's high energy density is a positive feature. The battery, on the other hand, cannot simply be used to power gadgets that require a modest quantity of electricity. The battery can also be used to increase the voltage in capacitors, making it an efficient solution for medical devices. The energy density of the CR2016 battery is great. Many of our modern devices require electricity, which the batteries can provide. Because it does not have a mercury electrode, sealed Cr2032 can also be utilized in medicine and medical equipment. This makes them environmentally benign and ensures that neither the user nor the gadget is harmed. The company creates high-energy-density batteries. The battery is intended to last around 2 hours under heavy use. On moderate usage, this battery can last up to two days. 4.4 Many Of UseThere are various types of batteries to utilize in the present era. A broad variety of batteries are available to assist people power up their phones. Cr2016 is the name of a type of battery that is now available on the market. Because of its efficiency and performance, this battery has grown in popularity. Though this battery has a long life, it still requires rechargeable batteries as well as other accessories such as an external charger or a slot for extra batteries. The Battery Cr2016 must also be protected from dirt and water damage in order to last longer. For consumers looking for durability, Cr 2016 batteries will last longer than devices that use other types of batteries. This eliminates the need to replace the battery for an extended period of time. Ⅴ How to Replace a CR2016 BatteryA CR2016 coin cell battery is a tiny, circular lithium coin cell battery. Many household products use batteries, including keyless auto remotes, watches, MP3 players, calculators, and PDA devices. The battery is not rechargeable, and it must be replaced after it dies. Step 1: Examine the battery bay of the object that requires a new battery. Depending on the item, maker, and model, the battery compartment is positioned in different regions and can be accessible in various ways. If you're not sure how to get to the battery bay, consult the product's user manual. Step 2: Lift the old CR2016 battery from the battery bay. Step 3: Insert the new battery into the battery bay. The battery lies flat in the battery bay. Follow the +/- indicators in the battery bay or on the battery cover for proper placement of the battery. Coin cell batteries have a plus (+) mark on one side of the battery and a minus (-) mark on the opposite side. Ⅵ Things  To Consider When Buying CR2016 BatteryThere are numerous factors to consider when purchasing a battery. The first consideration  is the type of device that will be powered by the battery. The size and shape of the device might also influence which battery type is best suited for it. If you're unsure about the type of battery your device requires, speak with an expert at your local electronics store or read related articles. 6.1 MaintenanceWhen purchasing a new CR2016 Battery, it is critical to consider battery maintenance. Some batteries may require very little maintenance, while others may necessitate a large amount. Before choosing a battery, make sure you understand what it requires so that you don't wind up with an expensive product that requires a lot of attention and money to maintain functioning. Before purchasing a battery, there are a few things to consider. First, assess whether the battery requires any maintenance at all. Some batteries are totally sealed and require no maintenance. These CR2016 Batteries are usually the finest alternative  because there is no risk of leaking or leakage, which can damage your gadget. If you are unsure whether your battery requires maintenance, consult the user guide before making a purchase. Once you've concluded that your newly purchased CR2016 Battery requires maintenance, you'll want to make sure you have all of the materials you'll need. You'll need distilled water and possibly some rubbing alcohol. Other varieties of CR2016 Battery require certain chemicals to maintain them, so if you're unsure, do some study before purchasing anything. 6.2 Battery SizeThose looking to purchase a CR2032 battery must examine the battery size. The CR2032 battery, also known as the DL2020, is cylindrical in shape, similar to AA, C, and D-cell batteries. Most notably, the CR2032 battery can be used in camera flashes or other high-power devices. While the size of the CR2016 battery is not an issue, it is vital to examine the battery size when selecting the battery. The CR2016 Battery comes in a variety of sizes, so choose the one that best suits your needs. When purchasing CR2016 batteries, the battery size must also be addressed. This battery is available in three sizes: small, standard, and big. Small is around the size of an AA battery but has just 1.5 volts. A tiny battery will typically last between 2 and 4 hours. The largest size is roughly the size of two AA batteries, but contains only 1.2 volts and can power devices such as flashlights or wireless mice for up to 25 hours. 6.3 Cranking VoltageI just bought a new CR2016 battery and was wondering what voltage it has because I couldn't see it on the box. Cranking Voltage is the greatest voltage provided by a battery for a brief period of time when starting a car or other vehicle. It's also referred to as boost. Heavy loads and powerful currents in an engine are referred to as boost. Working voltage is greater than 10% of cranking voltage but less than 100% of full load voltage. However, because to the cost and power necessary to supply it, full load voltage is not always accessible. When purchasing a CR2016 battery, you should consider the Cranking Voltage. Before purchasing a battery, make sure to check the cranking voltage. The higher the Cranking Voltage, the better it will perform when subjected to large loads. 6.4 Battery FreshnessWhen determining what sort of battery to buy, consider the voltage, the amount of time until the battery is discharged, and the battery's "freshness." Battery freshness is defined as the length of time the battery has been manufactured. The longer an object has been manufactured, the newer it is. A newer CR2016 lithium coin cell outlasts an older CR2016 lithium coin cell.   When purchasing CR2016 batteries, I strongly advise you to evaluate the battery freshness. When you buy a new battery and it doesn't last as long after a few charges, you're usually unable to return it. Reducing the size of your lawn with the right equipment will save you time and money on electric bills. The demand for power grows in tandem with the number of gadgets people need to stay connected. It is feasible to limit your power use by switching to ENERGY STAR certified devices, purchasing only what you need, turning off TVs and computer monitors when not in use, and unplugging other charging electronics–but if running out of energy is unavoidable, there are some things you can do. 6.5 Reserve CapacityWhen purchasing a CR2016 battery, a corporation should always consider the Reserve Capacity, as this is a factor that might affect the battery's performance. This component determines how much total charge the battery can hold to replace what has already been used up before it needs to be recharged. The greater the Reserve Capacity, the greater the total discharge that can occur before the next recharge cycle. It's critical to understand how many Amp-hours a certain model provides, which translates to roughly half of capacity in Ah. If you only want to use your battery on occasion, this is less significant because you will be charging it rather frequently. When purchasing a CR2016 battery, it is critical to consider the Reserve Capacity. The Reserve Capacity of your battery determines how long it can hold power. In other words, it decides how long the battery can provide power before being entirely depleted. A battery with a high reserve capacity may power things for a longer period of time, hence it may be advisable to utilize this type of battery in an emergency. If you're going to use the battery to power something that has to be held for a lengthy amount of time, get one with a higher Reserve Capacity. One factor to consider when purchasing a CR2016 battery is its reserve capacity. When choosing a CR2016 battery, it is critical to evaluate how long it can work before entirely depleting its charge. Some batteries have a 120-minute backup capacity, while others can go up to 220 minutes. Ⅶ CR2016 vs. CR2025 vs. CR20327.1 CR2016 vs. CR2025 vs. CR2032: What are the Similarities?Naming SchemeCR: The letter C indicates that the battery uses a chemical composition, Lithium Manganese Dioxide. The letter R indicates the battery shape, in this case, round.First two digits: The first two numbers in the battery code indicate the battery’s diameter in millimeters. All three of these batteries are 20 mm in diameter.Second two digits: The second two numbers in the battery code indicate the thickness of the battery. The CR2016 is 1.6 mm thick, while the CR2025 and CR2032 are 2.5 and 3.2 mm thick. Usage: All three types of batteries are utilized in a wide variety of small devices, ranging from car remote key fobs to laser pens, children's toys, and much more. The CR2032 battery is commonly used in personal computers to retain the CMOS memory. Voltage: All three batteries have a voltage of 3 volts. They could all be interchangeable in theory, but we'll get to that later. Diameter: As indicated by the battery code, all three batteries are 20 mm in diameter. Chemistry: The same Lithium Manganese chemical composition is used in all of these batteries. 7.2 CR2016 vs. CR2025 vs. CR2032: What are the Differences?CR2016 vs CR2025 Lithium Batteries - What is the Difference? CR2016 vs CR2032 Lithium Batteries - What is the Difference? The CR2016, CR2025, and CR2032 differ primarily in two ways: battery thickness and battery capacity.  CR2016CR2025CR2032Thickness1.6 mm2.5 mm3.2 mmCapacity90 mAh170 mAh220 mAh Difference in thicknessThe most noticeable difference is the thickness of the battery. As previously stated, the battery code defines the thickness in tens of millimeters, therefore the 2016 is 1.6 mm thick. The only physical difference between the batteries is their thickness. The thickness difference is one barrier to adopting a CR2032 instead of a CR2016, but we also need to consider battery capacity. Difference in battery capacityThe difference in thickness is due to the battery capacity. The capacity grows as the case thickness increases. Capacity is significant for a number of reasons, including: Some devices will not work with a battery with a lower capacity The greater the capacity, the longer the battery will last The CR2032 has more than double the capacity of the CR2016: CR2016 – 90 mAhCR2025 – 170 mAhCR2032 – 220 mAh But what exactly does this capacity rating imply? Here's a quick comparison to show the difference. If all three batteries were used to power a single 20 mAh LED bulb, the CR2016 would last 4.5 hours, the CR2025 8.5 hours, and the CR2032 11 hours. So it's easy to understand why it could be tempting to try to swap a CR2032 for a CR2016, but are they interchangeable? 7.3 CR2016 vs. CR2025 vs. CR2032: Are These Batteries Interchangeable?Yes, the three battery types are compatible in theory. However, there are certain challenges. The diameter and voltage of all three batteries are equal, implying that one kind can be used in place of another. The issue is caused by the differing thicknesses of the batteries. The thinner battery will be too loose in the compartment, while the heavier battery may not fit or may damage something by forcing it in. *Batteries that can be interchanged: CR2016 vs. CR2025; CR2025 vs. CR2032Because the thickness difference between the CR2032 and the CR2025 is only 0.7 mm, either one can usually be used. The same is true for CR2025 and CR2016, where the thickness difference is 0.9 mm. This should work OK as long as the battery fits firmly without destroying any portion of the battery housing. *CR2016 vs. CR2032: Are They Interchangeable?The CR2032 battery, with equivalent diameters and voltages, can theoretically be used to replace a CR2016 battery. However, because the CR2032 is twice as thick as the CR2016, it may be too thick to fit into the battery slot without bending or harming something. *Can I use two CR2016 batteries in place of a CR2032? Many people believe that because the CR2032 is exactly twice the width of the CR2016, they can simply use two CR2016s instead of a single CR2032. While this appears to be correct in theory, there is a defect. By stacking two CR2016s on top of each other, you create a series of batteries with a voltage output of 6 volts. Do not try this! While the greater voltage may not harm anything, there is a chance it will, so don't do it. Solution: Using a penny to stack with CR2016 If you need to replace a CR2032 battery but only have a CR2016 on hand, there is a technique to make it work without damaging anything. You might use a cent coin instead of two CR2016s to achieve the desired thickness. A penny is the appropriate size, and when minted, it will be 1.52 mm thick, which is nearly identical to the CR2016. The metal penny is also conductive and will securely retain the battery. Ⅷ CR2016 Battery EquivalentsThe equivalents of the battery of this type are absolutely everything with the same numerical designation - 2016. Among them are popular:ECR2016;KCR2016;BR2016;LM2016;5000LC;Others with numbers 2016. Ⅸ Using WarningModern CR2016, CR2025, and CR2032 batteries have no lead, cadmium, or other heavy metals, yet they are still deadly if ingested. They are not simple to swallow with a 20mm diameter, however keep them away from children and dogs just in case. And if something like this happens, contact 911 immediately. Despite the fact that they do not contain heavy elements, they can produce electrolytic reactions in the body that can be quite hazardous. Fortunately, most CR2016 and comparable batteries are packaged in "children safe" containers, making them inaccessible to children. Even such products, in my opinion, can be opened by a determined child armed with scissors... Ⅹ Frequently Asked Questions About CR20161. Can I use a CR2032 in place of a CR2016?Using a CR2032 battery to replace a CR2016 battery is not always the best option. These two batteries have different voltages, and the CR2032 battery has a higher capacity. This may cause problems with your device due to running on an unstable voltage, or it may not last as long because it is being drained too quickly for its size. If you need to replace one of these batteries, consider alternative possibilities on the market before deciding which one will work. 2. Why should I care about the differences between CR2016 and CR2032?It is critical to understand the distinction between CR2032 and CR2016 batteries because they have almost identical properties but differ in size, capacity, and voltage. If you're looking for a CR2016 or CR2032 battery, make sure it's the right match by researching what your gadget requires before you buy. 3. What are the benefits of using a CR2032 over a CR2016 battery?A CR2032 cell lasts around four times as long as a CR2016 battery, and because it is larger, it does not snap as often, making it safer for toys and some children's devices. 4. How long does a CR2032 battery last?There are several elements that can influence how long the battery lasts. The important thing to understand is that whether you obtain one with a ten-year or three-month shelf life is determined on where it is stored and when it was created. If they were recently manufactured, there should be no reason why your batteries couldn't have a shelf life of up to ten years. 5. Are there safety hazards associated with CR2032 and CR2016 batteries?Yes, there are some risks involved with using these sorts of coin-cell batteries. To minimize unintended consequences, store your batteries correctly and keep them away from minors who may consume the hazardous chemical if it drips from the device. To avoid environmental concerns, you should also be aware of the right disposal techniques for CR2032 and CR2016 batteries, as well as any other type of battery. You will also be helping to safeguard the environment in this way. 

IntroductionIn electronics, the diode has the unique characteristic of unidirectional conduction. The main functions are rectification, voltage stabilization, and detection. In addition, there are light-emitting diodes(LED) added with different materials for indication and illumination. In a diode circuit, current can only flow in from the anode and flow out of the cathode. According to different circuit requirements, there are many different types of diodes to choose from. Most of the early diodes were made of germanium single crystals. Later, with the solution of silicon materials and manufacturing processes, silicon tubes have been developed and popularized. Here's how to distinguish silicon(Si) diodes and germanium(Ge) diodes.CatalogIntroductionⅠ Circuit Properties: Si Tube vs Ge Tube1.1 Differences between Ge and Si Diode1.2 Differences between Ge and Si Transistor1.3 SummeryⅡ Common Diode Types UsesⅢ Common Transistor Models UsesⅣ New Development: SiC Schottky Diodes4.1 SiC Schottky Diode Basic4.2 SiC Tech Characteristics4.3 SiC Schottky Diode ApplicationsⅠ Circuit Properties: Si Tube vs Ge Tube1.1 Differences between Ge and Si DiodeThe circuit properties of Si diodes and Ge diodes are the same, and the manufacturing process is also the same. Due to the difference in materials, the thermal stability of Si diodes is good, and the thermal stability of Ge diodes is slightly poor.1) When the current is the same, the DC resistance of the Ge tube is smaller than that of the Si tube. However, as for AC resistance, the situation is opposite.2) According to experimental research, the Ge diode starts to have current at 0.2V in the forward direction, while the Si diode does not start to have current until 0.5V, that is to say, the initial voltages for the two to reach conduction are different.3) Under reverse voltage, the leakage current of silicon tube is much smaller than that of germanium tube. After the start of conduction, the Ge tube current increases slowly, and the Si tube current increases relatively quickly.4) The threshold voltage of silicon tube is higher than that of germanium tube, because the threshold current of silicon tube is much smaller than that of germanium tube. Generally, the threshold voltage of a silicon tube is about 0.5V~0.6V, and the threshold voltage of a germanium tube is about 0.1V~0.2V.5) Temperature changes have a greater impact on Ge diodes, but less on silicon diodes. Therefore, silicon tubes have better high temperature resistance than Ge tubes.6) Forward voltage required for diode conduction:Diode TypesForward Conduction VoltageSi0.7VGe0.15VIt can be seen from the above table that the forward voltage required for the silicon tube to be turned on is higher than that of the germanium tube, so the diode can be distinguished by knowing the forward voltage.In addition, there is a very direct method to measure your diode with the Ω barrier of a multimeter. As shown in the figure, the red pen (anode) of the multimeter is connected to the cathode of the diode, and the black pen (cathode) is connected to the anode of the diode. If the resistance of the tested diode is around 1kΩ, it is a germanium tube; if the resistance is 4~8kΩ, it is a silicon tube.Compared with germanium diodes, silicon diodes have higher voltage resistance, shorter response time, and stable performance. In most circuits, silicon tubes can replace germanium tubes, but its forward pressure drop is higher than that of germanium tubes. Therefore, in some specific environments, such as small signal detection circuits, germanium tubes are better.1.2 Differences between Ge and Si TransistorThe main difference is that the junction voltage drop is different, the forward voltage drop of the germanium tube is lower about 0.3V, and the silicon tube is higher about 0.7V. In addition, silicon materials are abundant and manufacturing processes are suitable for mass production, so they are widely used and become the protagonist of electronic devices.Germanium semiconductor materials have high electron mobility and are suitable for low-voltage and high-current devices, but the temperature characteristics of it is worse than that of silicon materials. The reverse leakage current of PN junctions is much larger than that of silicon materials. Therefore, silicon tubes have to be used in high-power devices and high back-pressure devices. The triode has two PN junctions. In terms of a PN junction, the forward voltage of the PN junction of the germanium tube is reduced to only 0.3V, while the silicon tube is 0.7V. The reverse withstand voltage germanium tube is very low, so it is easy to reverse breakdown. Therefore, the penetrating current of the Ge tube is relatively large, noise will be generated in the amplifying circuit, and it is easy to be damaged. 1.3 SummeryGermanium diodes was used a lot in early electronics, such as radios, but they have largely been replaced by silicon diodes. Because the structure of germanium crystals will be destroyed at higher temperature, while Silicon crystals are not easily damaged by excess heat. What's more, peak inverse voltage ratings of silicon diodes are greater than germanium diodes. As for price, Silicon material has low cost and its producibility of high quality silicon dioxide needed for impurity diffusion and surface passivation processes. Therefore, germanium tubes were only produced before the 1970s. Ⅱ Common Diode Types Uses① Zener DiodesThe Zener diode is also made of a PN structure. It is in the reverse breakdown state when working (the ordinary diode will be damaged in the reverse breakdown zone). When connected to the circuit, it should be reversed, that is, the anode of the Zener diode should be connected with the cathode of the voltage stabilizing circuit, so is the rest. The voltage stabilizing tube uses its reverse breakdown current to change in a wide range, the reverse breakdown voltage is basically unchanged, to achieve the purpose of voltage stabilization.② Light-emitting DiodesThe light-emitting diode emits light when it passes forward current, and has the performance of electro-optical conversion. The visible light includes red, yellow, green, blue, purple, etc. It is widely used in various electronic equipment as working status indicator.③ PhotodiodesThe reverse current of the photodiode increases with the increase of the light intensity. Its main feature is: the tube works in the reverse state, and the reverse current is proportional to the illuminance.④ Rectifier Diodes for AutomobilesThe working principle of the diode for automobile silicon rectifier generator is basically the same as that of other diodes, but the external structure is different from that of general diodes. It has one lead pole and the other pole is a shell. It is divided into two types: positive diode and negative diode. The terminal is the positive pole and the shell is the negative pole, while the leading end of the negative diode is the negative pole and the shell is the positive pole. In order to facilitate identification, the positive diode is usually coated with a red dot and the negative diode is coated with a black dot.⑤ Freewheeling DiodeFreewheeling diodes are common used in automobiles. In addition, fast recovery diode (a kind of semiconductor diode with good switching characteristics and short reverse recovery time) is mainly used for switching power devices (such as IGBT or MOSFET) of various power converters to play a freewheeling effect. Ⅲ Common Transistor Models UsesThe following table lists some commonly used transistor models and their main parameters, packages and alternative models.ModelBasic ParametersDescriptionPcVCBOVCEOVEBOhFEIC2SC2655(NPN, TO-92L)0.9W50V50V5V*2AHigh-speed switching tube, used for high-current PWM push-pull drive, complementary to the 2SA10202SC9013(NPN, TO-92)0.625W40V20V5V84-2020.5AComplementary to  the SS90122N5551(NPN, TO-92)0.63W180V160V6V30-2500.3AHigh voltage tube, complementary to the 2N5401KSP2222A(PN2222A)(NPN, TO-92)0.625W75V40V6V35-30006AUniversal switch type, complementary to the KSP2907AS8050(NPN, TO-92)0.625W40V25V5V50-3000.5AComplementary to the S8550BD681A(NPN, TO-12640W100V100V5V750-15004ACan drive large relays, Darlington tubeTIP41/A/B/C(NPN, TO-220)60W40~100V40~100V5V15-756AMiddle Power tubes, complementary to the TIP42, can be used for IGBT PWM driveMPSA44(NPN, TO-92)0.625W500V400V6V40-3000.3AHigh voltage tubeKSP2907A(PNP, TO-92)0.625W-60V-60V-5V50-3000.6ACommon-type, complementary to the KSP2222AS8550(PNP, TO-92)0.625W-40V-25V-5V50-3000.5AComplementary to the S80502SA1020(PNP, TO-92L)0.9W-50V-50V-5V40-2402AHigh-speed switch tube, complementary to the 2SC26552SA684(PNP, TO-92L)1W-60V-50V-5V50-3401ADarlington tubeTIP42/A/B/C(PNP, TO-220)65W-40~-100V-40~-100V-5V15-756AMiddle power tubes, complementary to the TIP41, can be used for IGBT PWM driveKSP94(PNP, TO-92)0.625W-400V-400V-6V40-3000.3AHigh voltage tubeⅣ New Development: SiC Schottky Diodes4.1 SiC Schottky Diode BasicSchottky diodes, also known as hot carrier diodes, form a Schottky barrier through metal and semiconductor contacts to achieve rectification. Compared with ordinary PN junction diodes, the reverse recovery inertia of it is very low. Therefore, Schottky diodes are suitable for high-frequency rectification or high-speed switching.Silicon carbide (SiC) is a high-performance semiconductor material, so SiC Schottky diode have advantages of higher energy efficiency, higher power density, smaller size and higher reliability. It can be used in power electronics to break the limit of silicon, and becomes the preferred device for new energy and power electronics.4.2 SiC Tech CharacteristicsSiC is a compound semiconductor composed of silicon and carbide. It provides a number of advantages over silicon. The band gap of SiC is 2.8 times that of silicon (wide band gap), reaching 3.09 eV. Its insulation breakdown field strength is 5.3 times that of silicon, up to 3.2MV/cm, and its thermal conductivity is 3.3 times that of silicon, about 49w/cm·k. Like silicon semiconductor materials, it can be made into junction devices, field-effect devices, and special Schottky diodes. Here is SiC characteristics:1) Silicon carbide single-carrier devices have a thin drift region and low on-state resistance, about 100-300 times smaller than silicon devices. Due to the small on-resistance, the forward loss of the silicon carbide power device is small.2) The silicon carbide power device has a high breakdown voltage due to its high breakdown electric field. For example, the voltage of commercial silicon Schottky diode is less than 300V, while the breakdown voltage of the first commercial SiC Schottky diode has reached 600V.3) SiC has higher thermal conductivity.4) SiC devices can work at higher temperatures, while the maximum operating temperature of Si devices is only at 150ºC.5) SiC has high resistance to radiation.6) The forward and reverse characteristics of SiC power devices vary little with temperature and time, and their reliability is good.7) SiC devices have good reverse recovery characteristics, with low reverse recovery current and switching loss.8) SiC devices can reduce the volume of power devices and circuit losses.4.3 SiC Schottky Diode ApplicationsSiC Schottky diodes can be widely used in medium and high power fields such as switching power supplies, power factor correction (PFC) circuits, uninterruptible power supplies (UPS), photovoltaic inverters, etc., which can significantly reduce circuit losses and improve circuit operating frequency.Substituting SiC SBD(Schottky barrier diodes) for the original silicon FRD(fast recovery diodes) in the PFC circuit can make the circuit work above 300kHz, and the efficiency remains basically unchanged, while the efficiency of the circuit using silicon FRD above 100kHz drops sharply. As the operating frequency increases, the volume of passive components such as inductors decreases correspondingly, and the volume of the entire circuit board decreases by more than 30%. Frequently Asked Questions about Silicon and Germanium Diodes1. Why silicon diode is better than germanium diode?The structure of Germanium crystals will be destroyed at higher temperature. However, Silicon crystals are not easily damaged by excess heat. Peak Inverse Voltage ratings of Silicon diodes are greater than Germanium diodes. Si is less expensive due to the greater abundance of element. 2. How can I tell if I have a Ge or Si diode?You can easily distinguish Silicon and Germanium Diodes. Silicon diodes should read approx 0.7V and Germanium diodes should read 0.3V. A little difficult to distinguish Schottky diodes though. They should show approx 0.2V which is close to 0.3V. 3. What are the differences between silicon and germanium semiconductor?The key difference between silicon and germanium is that the Germanium has d electrons, but Silicon does not have any d electrons. Silicon and germanium, are both in the same group (group 14) of the periodic table. Hence, they have four electrons in the outer energy level. 4. What is difference between silicon and germanium?Silicon and germanium have four valence electrons but at the given temperature germanium will have more free electrons and higher conductivity than silicon. Silicon is more widely used in the electronic device than germanium since it can be used at a higher temperature. 5. What is the difference between silicon and germanium transistors?To answer you actual question, there are two significant differences between silicon and germanium transistors: germanium has a low melting point and germanium transistors have much less tolerance for high temperatures. The forward voltage drop of a germanium junction is lower than for silicon.

Ⅰ. Filter DefinitionIn electronics, a filter (signal processing) is a kind of devices or process that removes some unwanted components or features from a signal. Filtering is a class of signal processing, the defining feature of filters being the complete or partial suppression of some aspect of the signal. Most often, this means removing some frequencies or frequency bands. However, filters do not exclusively act in the frequency domain; especially in the field of image processing many other targets for filtering exist. As is known to all, electronic filters remove unwanted frequency components from the applied signal, enhance wanted ones, or both.Introduction to Signal FilteringCatalogⅠ. Filter DefinitionⅡ. Type of Filters and Functions  2.1 Type of Filters  2.2 Filtering FunctionsⅢ. Filter TechnologiesⅣ. Main Characteristic Indexes of FilteringⅤ. Filter Classifications Analysis  5.1 Passive Filter & Active Filter  5.2 Digital Filter & Analog FiltersⅥ. One Question Related Filter and Going Further  6.1 Question  6.2 AnswerⅡ. Type of Filters and Functions2.1 Type of FiltersFilters have different effects on signals of different frequencies. According to this fact, the basic filter types can be classified into four categories: low-pass, high-pass, band-pass, and band-stop. Each of them has a specific application in DSP. One of the objectives may involve digital filters design in applications. Generally, the filter is designed based on the specifications primarily for the passband, stopband, and transition band of the filter frequency response. The filter passband is the frequency range with the amplitude gain of the filter response being approximately unity. The filter stopband refers to the frequency range over which the filter magnitude response is attenuated to eliminate the input signal whose frequency components are within that range. The transition band means the frequency range between the passband and the stopband.Figure 1. Filtering Out the Noise (signal processing)Because there are many different standards of classifying filters and these overlap in many different ways, there is no clearly distinctive classification. Filters may be:non-linear or linearanalog or digitaltime-variant or time-invariant , also known as shift invariance.discrete-time (sampled) or continuous-timepassive or active type of continuous-time filterinfinite impulse response (IIR) or finite impulse response (FIR) type2.2 Filtering FunctionsSeparate useful signals from noise to improve signal immunity and signal-to-noise ratio.Filter out unwanted frequency to improve signal analysis accuracy.Separate single frequency from complex frequencFigure 2. Electronic FilterⅢ. Filter TechnologiesFilters can be built in a number of different technologies. Before that, it is necessary to know some basics of it deeply.Center frequencyThe main parameters of the filter: the center frequency of the filter's pass-band f 0, generally f 0 = (f 1 + f 2) / 2, f 1 and f 2 are boundary frequencies of band-pass or band-stop filter, which decreased by 1dB or 3dB. In addition, narrowband filters often use the smallest point of insertion loss as the center frequency to calculate the pass-band bandwidth. Cutoff frequencyIt refers to the right frequency point of the pass-band of the low-pass filter and the left frequency point of the pass-band of the high-pass filter, and it is usually defined by relative loss points, 1dB or 3dB. The relative reference for the relative loss is: the low-pass is based on the insertion loss at DC, and the high-pass is based on the insertion loss at a high-pass frequency at which no parasitic stop-band occurs. Pass-band bandwidthThe bandwidth of the filter is simply the difference between the upper and lower cutoff frequencies, while passband bandwidth is the difference between the upper and lower cutoff frequencies of, for example, a band-pass filter, a communication channel, or a signal spectrum. Insertion lossIt refers to the loss of the original signal in the circuit due to the introduction of the filter. And it is characterized by the loss at the center or the cutoff frequency. If it is the full-band interpolation loss, it must be emphasized.Note: When adding a filter at the input end, the impedance of the filter should be mismatched with the impedance of the power supply. The more severe the mismatch, the more ideal the attenuation is, and the better the insertion loss characteristics. That is, if the internal resistance of the noise source is low impedance, the input impedance of the EMI filter connected to it should be high (such as a series inductor with a large amount of inductance); if the internal resistance of the noise source is high impedance, the input impedance of the EMI filter should be low (such as a large parallel capacitor). Due to the imbalance of the line impedance, the two components will convert to each other during transmission, and the situation becomes complicated. RippleIt refers to the peak-to-peak value of the insertion loss that fluctuates on the basis of the average loss curve with the frequency in the 1dB or 3dB bandwidth (cutoff frequency). Pass-band riplpeThe amount of change in insertion loss in the pass-band with frequency. For example, in a 1dB bandwidth, it is 1dB. Pass-band standing wave ratio (VSWR)An important indicator for measuring whether the signal in the filter pass-band is properly transferred. Ideal VSWR is 1: 1, when mismatched, VSWR> 1. For an actual filter, bandwidth satisfies VSWR <1.5: 1, which is generally less than 3dB, and the proportion when at 3dB is related to the filter order and insertion loss. Return lossThe decibels (dB) of the ratio of the port's signal input power to the reflected power, and it is also equal to | 20Log10ρ |, where ρ is the voltage reflection coefficient. In addition, when the input power is completely absorbed by the port, the return loss value is infinite. Stop band rejectionIt is a major index to measure the performance of filter selection. The higher the index, the better the suppression of out-of-band interference signals. There are usually two formulations: one is how much dB is required to suppress a given out-of-band frequency fs, and the calculation method is the attenuation fs=As-IL; another is to propose a characterizing filter whose amplitude-frequency response is close to the ideal rectangle index of degree-rectangular coefficient (KxdB> 1), KxdB = BWxdB / BW3dB, (x can be 40dB, 30dB, 20dB, etc.). The more the filter order, the higher the rectangularity, in other words, the closer the K is to the ideal value 1, the more difficult it is to make an ideal filter. Delay (Td)It refers to the time required for the signal to cross the filter. The value is the derivative of the diagonal frequency of the transmission phase function. In-band phase linearityThis indicator characterizes the phase distortion introduced by the filter on the transmission signal in the pass-band. The filter designed according to the linear phase response function, which has good phase linearity, but its frequency selectivity is very poor. It is only used to pulse or phase-modulate signal transmission system applications. Order (stage)For high-pass and low-pass filters, the order is the sum of all capacitors and inductors in the filter circuit. For a band-pass filter, the order is the total number of parallel resonators; for a band-stop filter, the order is the total number of series and parallel resonators. Absolute bandwidth / relative bandwidthThis indicator is usually used for band-pass filters, which characterize the frequency range of signals that can pass through the filter, and reflects the frequency selection of the filter. Relative bandwidth is the percentage of absolute bandwidth to center frequency. Standing waveIt indicates the impedance matching between the filter port and the required system, and also it indicates how much of the input signal failed to enter the filter and was reflected back to the input. LossIt represents the energy lost after the signal passes through the filter, that is, the energy consumed by the filter. Pass-band flatnessThe absolute value of the difference between the maximum loss and the minimum loss in the pass-band of the filter, which characterizes the difference in energy consumption of filters for different frequency signals. Out-of-band rejectionIt is the "attenuation" outside the pass-band frequency range of the filter, which characterizes the filter's ability to select unnecessary frequency signals. Absolute group delayThe time it taken for a signal to pass from the input port to the output port within the pass-band of the filter. Group delay fluctuationThe difference between the maximum and minimum absolute group delay in the pass-band of the filter, which characterizes the dispersion characteristics of a filter. Power capacityIt refers to the maximum power of the pass-band signal that can be input to the filter. Phase consistencyThe difference in the phase of the transmitted signal between different filters of the same index in the same batch, which characterizes the differences (consistency) between batch filters. Amplitude consistencyThe difference of transmission signal loss between different filters with the same index in the same batch, which represents the differences (consistency) between batch filters.Figure 3. Low-Pass Electrical FilterⅣ. Main Characteristic Indexes of FilteringCharacteristic frequency① The pass-band cutoff frequency fp = wp / (2p) is the frequency of the boundary point between the passband and the transition band, at which the signal gain decreases to the specified lower limit.② Stop-band cut-off frequency fr = wr / (2p) is the frequency of the boundary point between the stopband and the transition band, at which the signal attenuation (reciprocal of the gain) decreases to the specified lower limit.③ The corner frequency fc = wc / (2p) is the frequency when the signal power is attenuated to 1/2 (about 3dB). In many cases, fc is often used as the pass-band or stop-band cutoff frequency.④ Natural frequency f0 = w0 / (2p), when there is no loss in the circuit, it refers to the resonance frequency of the filter, and complex circuits often have multiple natural frequencies. Gain and attenuationThe gain of the filter in the pass-band is not constant.① For the low-pass filter pass-band gain Kp, for the ordinary filters, it refers to the gain at w = 0; for the high-pass, it refers to the gain at w → ∞; for the band pass, it refers to the gain at the center frequency.② For the band-stop filter, the stop-band attenuation should be given, and the attenuation is defined as the inverse of the gain.③ The change amount of the pass-band gain △ Kp, refers to the maximum change amount of the gain at each point in the pass-band. If △ Kp is in dB, it means the variation of the gain dB value. Damping coefficient and quality factorThe damping coefficient is a characterization of a filter’s damping effect on a signal with an angular frequency at w0, and is an indicator of energy loss in the filter.The reciprocal of the damping coefficient is called quality factor, and is an important indicator of the frequency selection characteristics of the valence band-pass and band-stop filters, Q = w0 / △ w, where △ w in the formula is the 3dB bandwidth of the band-pass or band-stop filter, w0 is the center frequency, and in many cases the center frequency is equal to the natural frequency. SensitivityThe filtering circuit is composed of many components, and changes of parameter values of each component will affect the performance of the filter. The sensitivity of a certain performance index y of the filter to the change of a certain component parameter x is recorded as Sxy, which is defined as: Sxy = (dy / y) / (dx / x).This sensitivity is not the same concept with the sensitivity of measuring instruments or circuit systems. The smaller the sensitivity, the stronger the fault tolerance of the circuit, and the higher the stability. Group delay functionWhen the filter's amplitude-frequency characteristics meet the design requirements, in order to ensure that the output signal distortion does not exceed the allowable range, certain requirements should be put forward for its phase-frequency characteristic ∮(w). In filter design, the closer the group delay function d∮ (w) / dw is to a constant, the smaller the signal phase distortion. Ⅴ. Filter Classifications Analysis5.1 Passive Filter & Active FilterPassive filterA passive filter is composed of passive components only. It is based on the principle that the reactance of the capacitive and inductive components changes with frequency. The advantages of this type of filter are: simple circuit, causal power supply, and high reliability. Also there are disadvantages: the signal in the pass-band has energy loss, the load effect is relatively obvious, and electromagnetic induction is easy to cause when using inductive components. When the inductance is large, the size and weight of the filter are relatively large, which is not applicable in the low frequency range.The passive filter circuit has a simple structure and is easy to design, but its pass-band magnification and cut-off frequency change with the load, so it is not suitable for occasions with large signal processing requirements. Passive filter circuits are usually used in power circuits, such as filtering after DC power rectification, or LC (inductance, capacitor) circuit filtering when high current loads are used. Active filterActive filters are composed of passive components and active devices. The advantages of this type of filter are that the signal in the pass-band has no energy loss, even be amplified; the load effect is not obvious, and the mutual influence is small when multi-levels are connected. The simple method of cascading is easy to form high-order filter, and the device is small, lightweight, and does not require magnetic shielding. Their disadvantages are that the pass-band range is limited by the bandwidth of the active device and requires a DC power supply; the reliability is not as high as that of a passive filter, and it is not suitable for high voltage, high frequency, and high power applications.The load of the active filter circuit does not affect the filtering characteristics, so it is often used in places with superior signal processing requirements. Active filter circuit is generally composed of an RC network and integrated operational amplifier, so it can only be used under the condition of suitable DC power supply, and it can also be amplified. However, the composition and design of the circuit are also more complicated. Active filter circuits are not suitable for high voltage and high current applications. 5.2 Digital Filter & Analog Filters5.2.1 TerminologyA digital filter is an algorithm or device consisting of a digital multiplier, an adder, and a delay unit. The function of the digital filter is to perform arithmetic processing on the digital code of the input discrete signal to achieve the purpose of changing the signal spectrum. Digital filters can be made by computer software or large-scale integrated digital hardware.There are active and passive analog filters. Active filters mainly consist of op amps, op amps,  resistors, and capacitors. They have problems such as voltage drift, temperature drift, and noise, while digital filters do not get these problems, so they can achieve high stability and accuracy. 5.2.2 Differences between Digital filter & Analog filtersDigital filters are used for discrete systems, analog filters are used in continuous-time systems, and they can also be used in discrete-time systems, such as SC (switched capacitor) filters.From the point of view of implementation, analog filters are generally built with analog devices such as capacitors and inductors. Digital filters can be implemented by software or digital chips. It is troublesome to replace the capacitor and inductor when the technique parameters of the analog filter are changed. If there is a need for replacement, it is necessary to modify the coefficients (such as when implemented in software).From the technical view, for example, it is very difficult for analog filters to reach -60dB, and digital filters can easily reach this.The biggest difference between analog and digital filters is that the digital filter on the Fs/2 frequency is flipped, that is, symmetrical, while analog filters are not. Therefore, a large number of interpolation filters are selected in the DAC, and the image frequency is placed at a far frequency point, and then the analog filter regarded as a sound meter is used to filter out the image frequency in the radio frequency band.The expression of analog filters is different from digital filters: analog filters are represented by H (S), and digital filters are represented by H (Z). Analog filter is based on the approximation of amplitude-frequency characteristics, while digital filters can achieve phase matching.Figure 4. EMI Filters ImageⅥ. One Question Related to Filter and Going Further6.1 QuestionHow to Select EMI Filters?6.2 AnswerSome people think that the higher the insertion loss of an EMI filter, the better, and the more stages of the filtering network, the better. In fact, this is not the right way to choose a EMI filter. In addition, the more stages of the filtering network, the more expensive, the larger the size and weight. In practice, the best way to select and evaluate an EMI filter is to install it on a device for testing. As is known to all, the performance of a filter depends largely on the load impedance of the device. It cannot be derived from one data of impedance insertion loss. Because it is a complex function of the filtering element impedance and the equipment impedance, and its magnitude and phase change within the frequency range. What's more, different performance levels of conducted radiation control (FCC, VDE) and sensitivity control required by the filter selection test are performed on the device. Frequently Asked Questions about Filter (Signal Processing) Basics1. What is filter in digital signal processing?In signal processing, a filter is a device or process that removes some unwanted components or features from a signal. Filtering is a class of signal processing, the defining feature of filters being the complete or partial suppression of some aspect of the signal. 2. Why do we use filter in digital signal processing?Digital filters are used for two general purposes:(1) Separation of signals that have been combined(2) Restoration of signals that have been distorted in some way. Analog (electronic) filters can be used for these same tasks; however, digital filters can achieve far superior results. 3. What is filter response?In comparison, filters carried out by convolution are called Finite Impulse Response or FIR filters. As you know, the impulse response is the output of a system when the input is an impulse. In this same manner, the step response is the output when the input is a step (also called an edge, and an edge response). 4. Which filter is present in DSP system?An ideal bandpass filter and second-order approximations. With DSP software, there are two basic approaches to filter design: finite impulse response (FIR) and infinite impulse response (IIR). 5. What are the functions of filter in signal processing?In the field of signal processing, a filter is a device or process that, completely or partially, suppresses unwanted components or features from a signal. This usually means removing some frequencies to suppress interfering signals and to reduce background noise. 6. What is filter frequency?A frequency filter is an electrical circuit that alters the amplitude and sometimes phase of an electrical signal with respect to frequency. ... The frequency separating the attenuation band and the pass is called the cut-off frequency. 7. What is IIR filter in DSP?The infinite impulse response (IIR) filter is a recursive filter in that the output from the filter is computed by using the current and previous inputs and previous outputs. Because the filter uses previous values of the output, there is feedback of the output in the filter structure. 8. Where FIR filter is used?The term FIR abbreviation is “Finite Impulse Response” and it is one of two main types of digital filters used in DSP applications. Filters are signal conditioners and function of each filter is, it allows an AC components and blocks DC components. The best example of the filter is a phone line, which acts as a filter. 9. What are the most commonly used active filters?The most common and easily understood active filter is the Active Low Pass Filter. Its principle of operation and frequency response is exactly the same as those for the previously seen passive filter, the only difference this time is that it uses an op-amp for amplification and gain control. 10. Why IIR filter is unstable?So, for unstable filters, the impulse response is not absolutely summable. In another way, the impulse response never approaches zero. Again, for IIR filter, h continues to go on with n i.e. never goes to zero. So, IIR filters are supposed to be unstable. Recommended ReadingComplete Introduction and Classification of Filters and ApplicationsPrinciple and Function of the FilterCommon Applications of FilterClassification of Electronic Filters

IntroductionThe alternator diodes are a critical component of the rectifier assembly. Their primary function is to transform the alternator's output from Alternating Current (AC) to Direct Current (DC), which is required by your vehicle's battery and electronic systems.The charging output passes through a set of diodes (usually six or more) in the rectifier assembly. Because they handle high current, they generate significant heat. As the electrical load increases, the diodes become hotter. If you notice a change in the operation of your vehicle's electrical systems—such as dimming lights or a draining battery—the alternator diodes may be failing.It is critical to understand the early warning signals of failure and know a few simple tests you can perform. Early detection can help you avoid a costly breakdown and being stranded.Ⅰ How To Test An Alternator DiodeIn the video above, we demonstrate how to test an alternator diode with a multimeter to determine whether the rectifier pack is functional or defective. Flickering dashboard lights and headlights are classic symptoms of a bad alternator diode. Furthermore, a failed diode pack can cause "parasitic draw," killing your car battery overnight even when the engine is turned off, as current leaks back from the battery into the alternator.1.1 Testing With A Voltmeter (Multimeter)⚠ Safety First: Ensure loose clothing and jewelry are secured before leaning over a running engine. Keep hands clear of the serpentine belt and cooling fan.Step 1: Measure Your Battery’s Base VoltageBefore you begin, ensure your battery has a decent surface charge.Set your multimeter to 20 Volts DC. Ensure the multimeter's internal battery is fresh for accurate readings.Connect the probe tips to the battery terminals: Red to Positive (+), Black to Negative (-).Reading Analysis: A fully charged battery should read approximately 12.6V. If the base voltage is below 12.2V, the battery is partially discharged. If it is below 10.5V, it may have a dead cell and need replacement.Step 2: Measure The Charging System’s No-Load VoltageStart the engine and let it idle. Keep the engine speed at approximately 1500 RPM. Ensure all accessories (radio, AC, lights) are OFF.Connect the multimeter probes to the battery terminals again.Reading Analysis: You should see a rise in voltage, typically between 13.5V and 14.8V. Note: If the voltage exceeds 15.0V, the regulator is overcharging. If the voltage does not rise above base battery voltage, the alternator is not charging.Step 3: Measure The Charging System’s Load VoltageWith the engine running at 2000 RPM, turn ON high-load accessories (High-beam headlights, AC/Heater blower max, rear defroster).Check the multimeter reading.Reading Analysis: The voltage should remain at least 0.5V above the base battery voltage (typically staying above 13.5V). If the voltage drops below 12.6V under load, the alternator cannot keep up with demand.Step 4: Test The Alternator Diode (The Ripple Test)Correction: The original text stated that a reading of 0.001 indicates failure. This is incorrect. A reading of 0.00 (or very close to it) is good. High AC voltage indicates failure.Switch your multimeter to the AC Voltage setting (lowest scale, e.g., 200mV or 2V).With the engine running at approx 1200 RPM, connect the probes to the battery terminals.Reading Analysis: A good alternator should produce very little AC current (Ripple).0.00V - 0.05V (50mV): Excellent condition.0.5V (500mV) or higher: Bad Diode. The rectifier is leaking AC current into the system. This requires alternator replacement.1.2 Testing Without A VoltmeterWhile a multimeter provides scientific accuracy, physical inspection can offer clues.1. Assess The Alternator Belt Drive ConditionCheck the serpentine belt tension and condition. A glazed, cracked, or loose belt can slip, preventing the alternator from spinning fast enough to charge, mimicking a bad diode.2. Listen For Unusual SoundsListen for a high-pitched whine or a growling sound.Whining: Often indicates a failed diode allowing AC ripple, which causes the windings to vibrate.Grinding/Growling: Indicates failed internal bearings.3. Do A Headlight TestPerform this in a dark setting against a wall.Turn on the headlights with the engine running.Have a helper rev the engine. The lights should brighten slightly or stay steady.If the lights flicker or pulse rhythmically, this is a strong indicator of a bad diode (AC Ripple).4. Magnetic Screwdriver TestNote: Be extremely careful near moving belts. Bring the tip of a screwdriver near the rear bearing cover of the alternator (not the pulley). A strong magnetic pull indicates the internal field coil is energized. No magnetism while the car is running suggests a failure in the rotor or brushes.Ⅱ Alternator Diode ReplacementNote on Modern Vehicles: In the past, it was common to replace just the brushes or the diode pack (rectifier bridge). However, on modern alternators, these components are often soldered deep within the unit or integrated with complex electronics.If you have a rebuildable unit (like older Denso or Bosch models):Remove the alternator from the vehicle.Remove the rear housing cover (often held by 8mm or 10mm nuts).Unsolder or unbolt the Rectifier Bridge and Brush Holder.Install the new components, ensuring clean electrical contacts.For most users, replacing the entire alternator is the recommended path to ensure reliability, as worn bearings usually accompany failed diodes.Ⅲ FAQ1. How do you know if your alternator has a bad diode?The most common symptoms are flickering headlights or dashboard lights, a high-pitched whining noise from the engine, and a battery that drains overnight (parasitic draw). A multimeter test showing more than 0.5V AC at the battery confirms this.2. What does an Alternator Diode do?The alternator generates electricity by spinning a magnet inside copper coils. This creates Alternating Current (AC). However, cars run on Direct Current (DC). The diodes act as one-way check valves that block the negative half of the AC wave and allow only the positive current to pass, "rectifying" it into DC power.3. What causes an alternator diode to go bad?Heat is the primary enemy. Diodes can fail due to:Using the alternator to charge a completely dead battery (excessive load).Jump-starting another car incorrectly (voltage spikes).Poor battery connections creating resistance.Normal aging and thermal cycling.4. How much does it cost to replace an alternator?(Updated for 2025) Costs have risen due to the complexity of modern charging systems.DIY Part Cost: A remanufactured alternator typically costs between $150 and $400 depending on the vehicle.Professional Installation: Including labor and parts, expect to pay between $450 and $900. Luxury vehicles with water-cooled alternators or "smart" charging systems can cost upwards of $1,200.5. What are the symptoms of bad alternator diodes?1. Battery Warning Light (Red battery icon).2. Whining noise (electrical interference).3. Electrical issues (radio cutting out, windows moving slowly).4. Rapid battery drain when parked.5. Smell of burning rubber or hot wire insulation.6. Can a bad alternator diode cause a car battery to run down?Yes. A "leaky" diode can allow current to flow from the battery back into the alternator when the car is off. This parasitic drain can empty a healthy battery in just a few hours or overnight.7. How many diodes does an alternator have?Most standard alternators have six diodes arranged in a rectifier bridge. Some heavy-duty or high-efficiency alternators may have 8 or more (avalanche diodes) to handle higher amperage loads.8. How to check an alternator diode with a multimeter (Resistance Mode)?If the alternator is disassembled, you can test individual diodes using the "Diode Check" mode on your multimeter.Bias Forward: Connect Red to the anode and Black to the cathode. You should see a voltage drop of roughly 0.5V to 0.7V.Bias Reverse: Reverse the leads. The meter should read OL (Open Loop) or infinite resistance.If you get a reading in both directions, the diode is shorted. If you get OL in both directions, the diode is open.Disclaimer: This guide is for informational purposes. Always consult your vehicle’s service manual for specific voltage specifications and safety procedures.

I IntroductionLaser sensor is a kind of sensor which uses laser technology to measure. It is generally composed of laser, optical parts and photoelectric devices. It can convert the measured physical parameters (such as length, flow, speed, etc.) into optical signals, and then use photoelectric converter to convert the optical signals into electrical signals. Through the filtering, amplification and rectification of corresponding circuits, the output signals can be obtained, so as to calculate the measured quantity. Laser technology has the characteristics of strong direction, high brightness and good monochromaticity. It is widely used in industrial and agricultural production, national defense and military, medical and health, scientific research and other aspects, such as distance measurement, precision detection, positioning, etc., as well as length benchmark and optical frequency benchmark.Laser Distance Sensor OverviewCatalogI IntroductionII What is Laser? 2.1 The Concept of Laser 2.2 Important Characteristics of Laser 2.3 Types of Laser 2.4 What can Laser Sensor Detect?III Laser Displacement Sensor 3.1 What is Laser Displacement Sensor 3.2 How Does Laser Displacement Sensor Work? 3.3 Application of Laser Displacement Sensor 3.4 What are the Parameters to Know When Choosing a Laser Displacement Sensor?IV Laser Distance Sensor 4.1 Classification of Laser Distance Sensors  4.2 Measuring Principle of Different Laser Distance Sensors 4.3 Application of Laser Distance SensorV Laser Sensor Application CaseVI FAQII What is Laser?2.1 The Concept of LaserLaser light is different from ordinary light. (See more about light and photoelectric effect in the article introducing light sensor and photoresistor)We need to use laser to produce laser light. In the normal state, most of the atoms in the laser are in stable low energy level E1. Under the action of appropriate frequency of external light, the atoms in low energy level absorb photon energy to excite and transition to high energy level E2. The photon energy E = e2-e1 = h V, where h is the Planck constant and V is the photon frequency.  On the contrary, when the frequency of light is V, the atom in level E2 will jump to the low energy level to release energy and emit light, which is called stimulated radiation. First of all, the laser makes the atoms of the working materials abnormally in the high-energy level (i.e. inversion distribution of the particle number ), which can make the stimulated radiation process dominant, so that the induced light with the frequency of V can be enhanced, and the large stimulated radiation light can be produced through the avalanche amplification of the parallel reflector, which is called laser light for short.Figure1. Laser2.2 Important Characteristics of Laser（1）High directivity, small divergence angle of light speed, the laser beam extends only a few centimeters from a few kilometers away.（2）High monochromaticity, the frequency width of laser light is more than 10 times smaller than that of ordinary light.（3）High brightness, laser beam convergence can produce temperatures up to several million degrees.2.3 Types of LaserLaser can be divided into four types according to working substance:（1）Solid state laserIts working substance is solid. Ruby laser, neodymium doped yttrium aluminum garnet laser (i.e. YAG laser) and neodymium glass laser are commonly used. Their structures are basically the same, characterized by small and solid, high power. At present, neodymium glass laser is the device with the highest pulse output power, which has reached tens of megawatts.（2）Gas laserIts working substance is gas. Now there are various kinds of gas atoms, ions, metal vapor, gas molecular lasers. Commonly used are carbon dioxide laser, helium neon laser and carbon monoxide laser, whose shape is like a common discharge tube, characterized by stable output, good monochromaticity, long life, but small power, low conversion efficiency.（3）Liquid laserIt can be divided into chelate laser, inorganic liquid laser and organic dye laser, the most important of which is organic dye laser. Its main feature is that the wavelength is continuously adjustable.（4）Semiconductor laserIt is a younger laser, and the more mature one is GaAs laser. It is characterized by high efficiency, small size, light weight and simple structure, and is suitable for carrying on airplanes, warships, tanks and infantry. It can be made into range finder and sighting device. However, the output power is small, the directivity is poor, and it is greatly affected by the ambient temperature.2.4 What can Laser Sensor Detect? (1) Laser measurement of lengthPrecise measurement of length is one of the key technologies in precise machinery manufacturing industry and optical processing industry. Modern length measurement is mostly based on the interference phenomenon of light wave, and its accuracy mainly depends on the monochromaticity of light. Laser is the most ideal light source. It is 100 thousand times purer than the best monochromatic light source (krypton-86 lamp). Therefore, the laser measurement range of length is large and the accuracy is high.  According to the optical principle, the relationship between the maximum measurable length L of monochromatic light and wavelength λ and spectral line width δ is L = λ 2 / δ. The maximum measurable length of krypton-86 lamp is 38.5cm. For a long object, it is necessary to measure in sections to reduce the accuracy. If He-Ne gas laser is used, it can measure tens of kilometers at most. Generally, the length within several meters can be measured with an accuracy of 0.1 μ M.Figure2. Laser Measure(2) Laser measurement of distanceIts principle is the same as that of the radio radar. After the laser is aimed at the target, the round-trip time is measured, and then the round-trip distance is obtained by multiplying the speed of light. Because of the advantages of laser, such as high directivity, high monochromaticity and high power, these are very important for the measurement of long distance, the determination of target orientation, the improvement of signal-to-noise ratio of the receiving system, and the guarantee of measurement accuracy, so the laser rangefinder is paid more and more attention.  The lidar developed on the basis of the laser rangefinder can not only measure the distance, but also the azimuth, velocity and acceleration of the target. It has been successfully used in the ranging and tracking of the artificial satellite. For example, the lidar using ruby laser has a distance measuring range of 500-2000 km with an error of only a few meters. At present, ruby laser, neodymium glass laser, carbon dioxide laser and Gas laser are often used as the light source of laser rangefinder.Figure3. Measuring Distance with Laser Sensor (3) Laser measurement of thickness Based on the principle of triangle ranging, a precise laser ranging sensor is divided at the upper and lower part of the C-frame. The modulated laser emitted by the laser hits the surface of the measured object. By sampling the signal of the linear CCD, the distance between the measured object and the C-frame is synchronously obtained by the linear CCD camera under the control of the control circuit. The thickness of the middle measured object is calculated by the data fed back by the sensor. Because the detection is continuous, the continuous dynamic thickness of the measured object can be obtained.Figure4. Thickness Measuring with Laser SensorThickness measurement by single laser displacement sensorPut the measured body on the measuring platform, measure the distance from the sensor to the platform surface, then measure the distance from the sensor to the measured body surface, and measure the thickness after calculation. It is required that there is no air gap between the measured body and the measuring platform, and the measured body is not cocked. These strict requirements can only be achieved offline.Thickness measurement by double laser displacement sensorA laser displacement sensor is installed above and below the measured body respectively, and the thickness of the measured body is d = C - (a + b). Among them, C is the distance between two sensors, a is the distance between the upper sensor and the measured body, and B is the distance between the lower sensor and the measured body. The advantage of this method for on-line thickness measurement is that it can eliminate the influence of the vibration of the measured body on the measurement results.  But at the same time, there are requirements for sensor installation and performance. The conditions to ensure the accuracy of measurement are that two sensor beams must be coaxial and that two sensor scans must be synchronous. Coaxiality is realized by installation, and synchronization depends on the selection of laser sensor with synchronization end.Figure5. Thickness MeasurementIII Laser Displacement Sensor3.1 What is Laser Displacement SensorThe laser displacement sensor is called the eyes of the robot and machine, and has an irreplaceable role in welding, blank manufacturing, mechanical processing, heat treatment, loading and unloading, assembly and other operations. So, what is a laser displacement sensor? The laser displacement sensor is a sensor that uses laser technology for measurement, and is composed of a laser, a laser detector, and a measurement circuit. As a new type of measuring equipment, the laser displacement sensor can accurately measure the position, displacement and other changes of the measured object, and can also measure precise geometric measurements such as displacement, thickness, vibration, distance, and diameter.3.2 How Does Laser Displacement Sensor Work?The laser displacement sensor can accurately and non-contactly measure the position, displacement and other changes of the measured object, and is mainly used to measure the displacement, thickness, vibration, distance, diameter and other geometric quantities of the object. According to the measurement principle, the principle of laser displacement sensor is divided into laser triangulation method and laser echo analysis method. Laser triangulation method is generally suitable for high-precision and short-distance measurement, while laser echo analysis method is used for long-distance measurement. The following is the introduction to two measurement methods of laser displacement sensor principle.TriangulationFigure6. Laser Displacement SensorThe laser emitter shoots the visible red laser to the object surface through the lens, and the laser reflected by the object passes through the receiver lens, which is accepted by the internal CCD linear camera. According to different distances, the CCD linear camera can "see" this light point at different angles. According to the distance between the laser and the camera known from this angle, the digital signal processor can calculate the distance between the sensor and the measured object. At the same time, the position of the beam in the receiving element is processed by analog and digital circuits, and the corresponding output value is calculated by microprocessor analysis, and the standard data signal is output in proportion in the analog quantity window set by the user. If switching value output is used, it will be conducted in the settings window and cut off outside the window. In addition, an independent detection window can be set for analog quantity and switch quantity output.Echo analysisThe laser displacement sensor can achieve a certain degree of accuracy by using the echo analysis principle to measure the distance. The sensor is composed of processor unit, echo processing unit, laser transmitter and laser receiver. The laser displacement sensor emits one million pulses per second through the laser transmitter to the detector and returns to the receiver. The processor calculates the time required for the laser pulse to meet the detector and return to the receiver, so as to calculate the distance value.  The output value is the average output of thousands of measurement results. It is the so-called pulse time method. The laser echo analysis method is suitable for long-distance detection, but the measurement accuracy is lower than the laser triangulation method, and the longest detection distance can reach 250m.3.3 Application of Laser Displacement Sensor(1) Dimension measurement: position identification of small parts; monitoring of whether there are parts on the conveyor belt; detection of material overlapping and covering; control of manipulator position (tool center position); device state detection; detection of device position (through the small hole); monitoring of liquid level; thickness measurement; vibration analysis; collision test measurement; automobile-related test, etc. (2) Thickness measurement of sheet metal: laser sensor measures the thickness of sheet metal. Thickness change detection can help to detect wrinkles, small holes or overlaps to avoid machine failure. (3) Cylinder measurement: angle, length, eccentricity of inner and outer diameter, conicity, concentricity and surface profile.Figure7. Application of Laser Displacement Sensor(4) Length measurement: place the measured component on the conveyor belt at the designated position, the laser sensor detects the component and simultaneously measures it with the triggered laser scanner, and finally obtains the length of the component. (5) Uniformity check: place several laser sensors in a row in the tilt direction of the workpiece movement to be measured, and directly output the measurement value through one sensor. In addition, the software can be used to calculate the measurement value and read out the result according to the signal or data. (6) Inspection of electronic components: two laser scanners are used to place the tested components between them. Finally, the data is read out by the sensor, so as to detect the accuracy and integrity of the component size. (7) Inspection of filling level in production line: laser sensor is integrated into the production and manufacturing of filling products. When the filling products pass through the sensor, it can detect whether the filling is full. The sensor can accurately identify whether the filling product is qualified and the quantity of the product by using the extended program of laser beam reflecting surface. 3.4 What are the Parameters to Know When Choosing a Laser Displacement Sensor?Some parameters that must be understood when selecting a laser displacement sensor are very important.(1) Resolution: generally refers to the minimum range of the sensor, that is, the maximum recognition rate of the sensor. If the parameter is marked as 1mm, then the resolution is equal to 1mm. (2) Repeatability: We must know that even if the measured object is at rest, the measured value will fluctuate slightly. The error margin of repeated measurement of the measured object at the same position in the static state is the repeat accuracy. For example, if the parameter is marked as 1μm, the repeat accuracy of the sensor is 1μm. (3) Full range (effective range): the rated effective range of the sensor. When selecting a sensor, we must select the sensor that contains the effective range according to the required detection distance. (4) Linear accuracy: the error between the measured value and the actual displacement. Linear accuracy is expressed as a percentage, but since the range is a range and the measurement accuracy is more difficult to reach the apex of the range, most sensors will mark the linear accuracy of the apex of the range to intuitively reflect the performance of the sensor. (5) Sampling frequency/sampling period: frequency refers to the number of measurements per second. The higher the frequency, the shorter the time it takes to make a measurement. The shorter the measurement time, the more suitable it is for the detection of high-speed moving objects. (6) Average sampling times: even in the static state, there will be slight measurement fluctuations. At this time, multiple measurements are required to calculate the average number to make the measured value stable and accurate.Figure8. Laser SensorIV Laser Distance SensorLaser ranging is one of the earliest applications of the laser. This is because the laser has many advantages such as strong directivity, high brightness, and good monochromaticity. Before 1965, the Soviet Union used a laser to measure the distance between the earth and the moon (384401km) with an error of only 250m. In 1969, the Americans landed on the moon with a retro-reflector on the lunar surface. They also used a laser to measure the distance between the earth and the moon, with an error of only 15cm. The basic principle of using laser transmission time to measure the distance is to determine the target distance by measuring the time required for the laser to travel to and from the target.Related recommendation: Proximity SensorFigure9. Laser Distance Sensor4.1 Classification of Laser Distance Sensors Laser distance sensor technology is divided into absolute distance measurement method and micro displacement measurement method according to the measurement range. Subdivided according to the measuring method, the absolute distance ranging method mainly includes pulse laser ranging and phase laser ranging, and the micro displacement measuring method mainly includes triangulation laser ranging and interferometric laser ranging.4.2 Measuring Principle of Different Laser Distance Sensors(1) Pulse Laser Distance SensorA pulse laser with a very short duration is emitted by a pulsed laser, and after reaching the target to be measured after the distance to be measured, part of the energy will be reflected back. The reflected pulsed laser is called an echo. The echo returns to the rangefinder and is received by a photoelectric detector. According to the interval between the main wave signal and the echo signal, that is, when the laser pulse travels from the laser to the target to be measured, the distance of the target to be measured can be calculated.  (2) Phase laser Distance SensorThe emitted laser light is emphasized, and the phase change of the modulated signal is used when the laser is propagated in space. According to the wavelength of the modulated wave, the distance represented by the phase delay is calculated. That is, the indirect method of phase delay measurement is used instead of directly measuring the time required for the round trip of the laser to achieve distance measurement. The accuracy of this method can reach the millimeter level.Figure10. Working Principle of Laser Distance Measuring Device (3) Triangulation Laser Distance SensorAs mentioned above, this measurement principle is that the light emitted by the laser is focused on the surface of the measured object after being focused by the condensing lens, and the receiving lens receives the scattered light from the incident light spot and images it on the photoelectric  position detector On the sensitive side. When the object moves, the relative distance of the object movement is calculated by the displacement of the light spot on the imaging surface. The resolution of triangulation laser ranging is very high, which can reach the order of microns.   Figure11. Triangulation Principle (4) Interferometric Laser Distance SensorBy moving the measured target and measuring the coherence, the distance increment measurement is completed by counting, so the sensitivity of the interferometric measurement is very high, which can reach the nanometer level.4.3 Application of Laser Distance SensorThe laser distance sensor is mainly used for: monitoring the position of moving objects; measuring the railway contact network, measuring the boundary of buildings; measuring unsuitable objects; industrial automation and intelligent production management; vehicle speed and flow statistics; industrial monitoring signal trigger control; tower crane XY positioning of crane; automatic target distance control; monitoring of ship's safe docking position; positioning of container; measurement of vehicle's safe distance; measurement of overhead cable and height limitation; measurement of width of boxes on conveyor belt.V Laser Sensor Application Case(1) Over-limit detection of vehicle width and heightThe laser sensor is used for rapid measurement, the network core of the PC industrial control computer and the visual programming software VB are used for real-time data transmission and processing, and the friendly interface control software is also designed. Field test data shows that the system has good real-time performance and high measurement accuracy, and has certain practical value. (2) Expressway toll stationUsed in highway toll stations to count and protect vehicles. Malaysian Teras has applied hundreds of BEA laser sensors to its manual and automatic toll station systems. The laser sensor uses the time-of-flight (TOF) measurement principle, which can form 4 planes in the detection area to detect the vehicle. At the same time, the product also has functions such as anti-collision and vehicle safety protection. Compared with the traditional light curtain, the laser sensor has the advantages of high sensitivity, high accuracy, easy installation, high cost performance and strong stability. (3) Google's second-generation unmanned vehicleIn addition to the laser sensor on the top, Google’s second-generation driverless car prototype is still quite obvious, and the other sensors are set very concealed. The front, rear and sides of the vehicle are clearly marked with the Google unmanned vehicle logo. The driving principle of Google's unmanned vehicle is to continuously collect various accurate data of the vehicle itself and the surroundings through many sensors installed around the car, analyze and calculate it through the processor in the car, and then control the driving of the car according to the calculation results . Unmanned vehicles will use GPS equipment and sensors to accurately locate the vehicle's position and speed, and judge pedestrians, vehicles, bicycles, signal lights and many other objects around it.Figure12. Google's Self-driving CarThe roof of this Lexus is equipped with a 360° rotating laser holographic sensor, which can sense the front, side and rear conditions of the car almost simultaneously. The data collected by the sensor will be input to the processor located on the right rear side of the vehicle through the green data line. This laser sensor can also allow unmanned vehicles to be accurately positioned globally. The original L-shaped Lexus logo on the front of the car was also removed and replaced with a radar sensor; it was used to measure the distance ahead and the speed of the vehicle in order to determine the condition of the vehicle ahead and control the safe acceleration and deceleration of the vehicle. The wheel hub of the tire is also equipped with a position sensor, which is used to detect wheel rotation and help the vehicle to locate. The heart of Google's unmanned vehicles-the processor is located on the right rear side of the vehicle, the data information from each sensor will be transmitted here through the data wire, and analyzed and processed through the software in order to accurately sense and judge the difference between the unmanned vehicles object. In addition to analyzing and judging the current position of objects around the unmanned vehicle, the unmanned vehicle also needs to be calculated by software to accurately predict the possible next position of each object. Finally, the unmanned car will make safe driving decisions based on all the collected data, including controlling the speed of the car and the surrounding distance. VI FAQ1. How does laser sensor work?The basic principle is optical triangulation using a CMOS linear imager. A diffuse triangulating laser distance sensor transmits a laser through a lens and to the target, which reflects the light back to the sensor. A lens focuses this reflected light into a small spot onto the CMOS linear imager. 2. What is the use of laser sensors?The definition of a laser sensor is, it is an electrical device used to sense minute objects and precise positions. This sensor uses a laser to produce light within a straight line. Its visible ray mark of the laser makes the arrangement very simple. Laser light includes light waves with similar wavelengths. 3. What are the types of laser sensors?Laser distance sensors.Displacement sensors.Laser projectors.Laser light curtains.Laser photoelectric sensors.Positioning lasers.Laser edge detection sensors. 4. Are laser sensors dangerous?Improperly used laser devices are potentially dangerous. Effects can range from mild skin burns to irreversible injury to the skin and eye. The biological damage caused by lasers is produced through thermal, acoustical and photochemical processes. 5. Is a laser a sensor?A laser sensor uses a 'laser' to emit light in a straight line. Its visible beam spot makes alignment and positioning very easy. Since the light beam is focused, the sensor can be installed without worries about stray light. The major types of laser sensors include reflective, thru beam, and retro-reflective. 6. What is the range of the laser sensor?Laser distance sensors are designed for non-contact distance measurements: laser gauges for measuring ranges up to 10m, laser distance sensors for up to 3,000m. 7. What is CMOS Laser Sensor?A CMOS image sensor combines with a step-less laser power adjustment algorithm to produce stable detection of all types of workpieces from black rubber with low reflectivity to stainless steel and other highly glossy materials. 8. Which laser sensor is used for measuring very long distances?LDM301 laser distance sensor series – fast measurement of long distances. The laser distance sensors of the LDM301 series use a measured time-of-flight principle to measure distances of 300 m for natural surfaces and 3,000 m for reflective surfaces. 9. How does a laser sensor measure distance?The distance measurement is based on the triangulation principle. The laser beam strikes the object as a small point. The receiver of the sensor (photodiode line) detects the position of this point. The angle of incidence changes according to the distance, and thereby the position of the laser point on the receiver. 10. How accurate are laser distance sensors?Compared to other types of laser sensors, OM70 sensors feature one of the thinnest beam shapes, helping to ensure a more precise measuring focus. For example, most point-type lasers typically only go down to 0.2mm x 0.75mm whereas the OM70 goes down to 0.05mm x 0.05mm.