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IntroductionⅠ What is the Backlit Keyboard? 1.1 Advantages of the Backlit Keyboard 1.2 Disadvantages  of the Backlit KeyboardⅡ How to Enable and Disable a Backlit KeyboardⅢ Compact Backlit Keyboard w/Force Sensing Resistor (USB) (Black) | SLK-79-FSR-USB by iKey    3.1 How Does a Force Sensing Resistor (FSR) Work?    3.2 How do Force Sensing Resistors Measure Force?    3.3 How do You Calibrate a Force Sensing Resistor?    3.4 How are Force Sensing Resistors Made?    3.5 Matrix or Single-Point Force Sensing Resistors    3.6 How are Force Sensing Resistors Used?Ⅳ Factors to Consider Before Purchasing a Backlit Keyboard    4.1 Price    4.2 Increased Power Usage    4.3 Brightness    4.4 RGBⅤ How Much does a Backlit Gaming Keyboard Cost?Ⅵ Frequently Asked Questions about Backlit KeyboardIntroductionThe term "backlit keyboard" refers to a keyboard that has a light beneath the keys. In low-light situations, the backlight illuminates the letters and symbols on the keys to make them visible. Because the print on the keys is semi-transparent, the light will pass through it like a window. Read this article to learn how to choose a backlit keyboard quickly.Video: Backlight KeyboardsⅠ What is the Backlit Keyboard?A backlit keyboard, also known as an illuminated keyboard or a backlit gaming keyboard, is one that has lights inside it. The lights illuminate the area behind and around the keys, making them visible in low-light or dark settings. For energy efficiency and increased brightness, the light source is typically made up of mini LED light bulbs. Backlit gaming keyboards are popular among computer gamers, but they can also be used for general computing tasks. G.SKILL 's multicolor backlit gaming keyboard is shown below. 1.1 Advantages of the Backlit KeyboardThe distinction between a backlit keyboard and a regular keyboard is that the backlit keyboards can be used in the dark because they are illuminated from behind the keys.The characters associated with each key on regular boards are simply printed on and do not light up. Backlit keyboards  are therefore the most versatile option.You may have one or more colors depending on the keyboard supplier and model.A colorful backlit keyboard is a way to go for the gamer or the person who wants to add a little flair to their computer hardware setup.While these keyboards do have a more youthful feel to them, they are suitable for anyone who is young at heart.In general, the F and J keys have raised lines on them if you look at your keyboard (you may have to feel your keyboard).It's supposed to help you navigate the board even when the lighting isn't ideal.To work properly, you must, of course, know how to type efficiently and not just with your pointer finger (aka index finger).Some argue that efficient backlighting is the answer.Laptops with lights can be both functional and attractive.Learn more about illuminated keyboards as the ultimate gaming, editing, or programming accessory. 1.2 Disadvantages of the Backlit KeyboardFigure 1 Backlit keyboardThey cost more than other types of keyboards. Most models with key lighting start around $800 and rise from there - sometimes dramatically.Illuminated keyboards use more energy than standard keyboards. It can drain your battery faster if it is not plugged in and charging.Ⅱ How to Enable a Backlit KeyboardTouching the keys or across the edge of the keyboard usually activates the backlit feature. When the keys or keyboard edges are not touched, the lights automatically turn off after a short period of time. Turning off the lights automatically helps to conserve battery energy, extending battery performance between charges.Backlit keyboards for laptops and desktop computers may also include special keys or FN keys for permanently turning the backlight on and off, as well as the ability to change the color. The special or FN key to press on a keyboard varies depending on the manufacturer of the keyboard or laptop.In the Windows Mobility Center, most new PC laptops allow you to change the backlighting on the keyboard. On Dell laptops, this is frequently Fn+F10 or simply F10. Fn+Spacebar is the hidden key for adjusting the backlit keyboard  on Lenovo laptops.Ⅲ Compact Backlit Keyboard w/Force Sensing Resistor (USB) (Black) | SLK-79-FSR-USB by iKeyThe SLK-79-FSR-M keyboard was created for mobile applications that require a small footprint. The SLK-79-FSR-M, which includes an integrated force sensing resistor pointing gadget with dual left-click capability, packs a lot of power into a small package. The SLK-79-FSR-M includes backlit keys for working in low-light environments. The SLK-79-FSR-M, like the other iKey keyboards, has sealed industrial silicone rubber keypads and sturdy ABS polycarbonate cases.Features:12 Keys for FunctionPointing Device With Integrated Force Sensing ResistorKeyboard with Red BacklightConfigurations for USB and PS/2 are available. 3.1 How Does a Force Sensing Resistor (FSR) Work?In recent years, printed, thin, and flexible sensors have created quite a stir in the design engineering community. This is largely due to the proliferation of smart, lightweight, and energy-efficient technologies that have become ingrained in our daily lives. Naturally, when designing these small but powerful devices and products, the embedded components that make them game-changers should share the same characteristics.Force sensing resistors (also known as printed force sensors or force-sensitive resistors) are a large and expanding class of embedded components, with many new sensor types introduced in recent years. Force sensing resistors    , on the other hand, are not a new technology. For decades, force-sensing resistors have been used as an embedded component.3.2 How do Force Sensing Resistors Measure Force?Most engineers know that the formula for force is an object's mass multiplied by its acceleration (or, F=M*A) or applied pressure multiplied by contact zone (F=P*Area). Newtons (N), pound-force (lbf), and other engineering units are used to represent "F" in these equations.Figure 2: When a force sensing resistor is applied, the conductance response as a function of force is linear.Pressure sensor resistors are not pre-calibrated to correlate a force reading to a known technology unit on their own. The force measurement result captured by a force sensing resistor. On the other hand, can be correlated to the applied force via a calibration procedure.Piezoresistive sensing technology is a force-sensing resistor, This means that they are passive elements that serve as variable resistors in an electrical circuit. As illustrated in Figure 1, when the sensor is unloaded, it has a high resistance (on the order of Megaohms (M)) that decreases as force is applied (usually on the order of Kiloohms (K)). When the inverse of resistance (conductance) is considered, the thermal conduction response as a function of force is linear within the sensor's specified force range.3.3 How do You Calibrate a Force Sensing Resistor?Force sensing resistors  can really be calibrated with as few as two-to-three known loads due to their resistance/conductance linear relationship.Furthermore, if the circuit is built with adjustable components, the sensor's sensitivity can indeed be adjusted for optimal performance in the specific force range.3.4 How are Force Sensing Resistors Made?A semi-conductive material – or semi-conductive ink – is sandwiched between two thin substrates to form force-sensing resistors. As illustrated in Figure 3, there are two types of force sensing resistor technologies: Shunt Mode and Thru Mode.Figure 3:  The differences between shunt and thru mode force sensing resistor technologies.Force sensing resistors  in the shunt mode are polymer thick-film devices made up of two membranes separated by a thin air gap. One membrane contains two sets of interdigitated traces that are electronically isolated from one another, while the other is coated with a special textured, resistive ink.Thru mode force-sensing resistors  are flexible printed circuits with two outer substrates of polyester film. Above and below a pressure-sensitive layer, silver circles with traces are positioned, followed by a conductive polymer. The two layers of the substrate are laminated together with an adhesive layer. 3.5 Matrix or Single-Point Force Sensing ResistorsFigure 4: Examples of different force sensitive resistor technologies.ForceSensing resistors  can be configured as single-point force sensors or as a matrix array to capture pressure distribution over a large area. Pressure mapping technology refers to the use of force-sensing resistor  matrices.Tekscan's FlexiForceTM sensors are a type of thru mode force-sensing resistor. This technology's flexibility, combined with its operating capabilities and ability to operate on simple circuitry, makes it an excellent choice for embedding into smart devices with limited space and power. FlexiForce sensors are also extremely adaptable. Size, shape,  electrical termination, electrical termination, sensitivity,  and operating temperature can all be customized to meet the needs of your application. 3.6 How are Force Sensing Resistors Used?While there are new applications for force-sensing resistor technology every day, the majority of them fall into one of four categories:Detecting or measuring the rate at which a force changes.Detecting or measuring a change in force relative to another object.Touch and/or contact detectionDetecting force thresholds to initiate some kind of action (e.g., IoT applications)This short video gives you a better visual understanding of the various applications for force sensing resistors, specifically FlexiForce force sensing resistors.Are you interested in purchasing force sensing resistors? Ⅳ Factors to Consider Before Purchasing a Backlit KeyboardBefore purchasing a system with a backlit keyboard, you should think about a few things. The following sections go over each of them:4.1 PriceBacklit keyboard laptops are significantly more expensive than those without. As a result, it is recommended that you only invest in a feature if you are certain that it will benefit you and improve your user experience. It is recommended that you skip this feature if you rarely use your computer in dimly lit environments or if you can type without looking. 4.2 Increased Power UsageYour battery  percentage will quickly be depleted by backlit keyboard  s. As a result, if you value durability over aesthetics, you should avoid purchasing a laptop with a backlit keyboard,  However, if you don't mind having your system plugged in the majority of the time, the reduced battery  life shouldn't be a big deal. Furthermore, if you purchase a laptop with a backlit keyboard.  you can turn the feature on or off according to your needs.4.3  BrightnessOne of the main benefits of purchasing a laptop with a backlit keyboard  is the ability to use your system effectively in dimly lit environments. As a result, you should make sure that the backlit keyboard on your laptop is bright enough to meet your needs.4.4  RGBIf you're convinced that a backlit keyboard is a must-have feature for your ideal laptop, then go for the best that the market has to offer. When purchasing a laptop with a backlit keyboard, make sure that the keyboard can switch between different color ranges to effectively adapt to your surroundings.Ⅴ How Much does a Backlit Gaming Keyboard Cost?Gaming keyboards with backlighting are more expensive than standard keyboards, costing around $90 or more. They come in both wired and wireless versions. Wireless models require batteries to operate and may include a USB cable for charging the batteries by plugging the keyboard into the computer.Backlit gaming keyboards are made by a variety of companies, the most popular of which are Corsair, G.SKILL, Logitech, and RAZER.Ⅵ Frequently Asked Questions about Backlit Keyboard6.1 Are there wireless backlit keyboards?These keyboards are wireless and have backlit keys together. ... With backlit keys you are able to work in dark or dim light surroundings whereas wireless connectivity allows you to get free of all wires. Wireless keyboards mostly use bluetooth and are battery powered.6.2 Does backlit keyboard drain battery?Powering the keyboard backlights is a lesser drain on the battery, but there's a built-in setting that I recently learned about that turns off the keyboard backlights after a period of inactivity too.6.3 Does LED keyboard consume more power?There is no difference between the amount of energy/electricity usage a light up/LED keyboard will use compared to a non-light/non-LED up keyboard.6.4 Can you buy a backlit keyboard?Keyboards do come in a variety of different sizes, configurations, and builds, but these don't influence whether the keyboard has a backlight. Both membrane keyboards and mechanical keyboards may be built with backlights. Also, backlights are integrated into both desktop keyboards and laptop keyboards.6.5 Does Microsoft make a backlit keyboard?Yes, it does!all Surface Laptop 3 models come with the same three levels of the backlit keyboard. You can control the backlit on the Surface Laptop 3 keyboard by pressing the F1 media key (Next to Esc key). 1st Press: Activate backlight at level 1 (min). 2nd Press: Activate backlight at level 2 (medium).6.6 Does the surface laptop 2 have a backlit keyboard?Surface Laptop 2 keyboard and trackpadThe Surface Laptop 2 features a full-sized chicklet style keyboard with 1.5 mm of travel (versus 1.3 mm in Surface Pro 6) and three-stages of backlighting.6.7 Does HP laptop have backlit keyboard?Many HP laptops have backlit keyboards, some just a single color, others with what's known as RGB lighting, that can be customized to show different colors.6.8 Does ASUS have backlit keyboard?Here you can learn more about ASUS keyboard hotkeys introduction. For part of Notebook models, backlit function key is F3 and F4 key . If they are available, they can enable the backlit by pressing FN and F4 keys (FN+F4 keys) at the same time. ... For Gaming Notebook models, it's generally on Up and Down keys.6.9 How do I make my laptop keyboard glow?Also, depending on your computer model, your PC may be configured to control the backlit keyboard via the F9 or F11 button rather than the F5 button. Practice the same simultaneous Fn + F11 operation to turn on a backlight keyboard light.

CatalogIntroductionⅠ What is a Hot Swap PCB?Ⅱ Custom Keyboard - Hotswap vs. Solderable PCB    2.1 Advantages of Hotswap PCB    2.2 Disadvantages of Hotswap PCB    2.3 Advantages of Solderable PCB    2.4 Disadvantages of Solderable PCBⅢ What Is a Hotswap Mechanical Keyboard?Ⅳ Why are so few hotswap keyboards available?Ⅴ How to Make Hot-Swappable Mechanical keyboard PCB?Ⅵ Relevant Information about "Hot Swap PCB"IntroductionWhen building a custom mechanical keyboard, one of the most contentious decisions is whether to use a hotswap PCB or a solderable PCB. Is one superior to the other? This article will go over the specifics of the hot swap PCB.Ⅰ What is a Hot Swap PCB?The need to solder on switches is one of the most intimidating obstacles for people looking to build a mechanical keyboard. Hot swap PCBs, on the other hand, come to the rescue! A printed circuit board, or PCB, is the brain of your keyboard.There are two ways to connect your mechanical switches to the PCB to register inputs.1.SOLDER PCBSoldering necessitates the use of a soldering tool and solder, a low-melting metal alloy. This method entails inserting the pins of a switch through holes in your PCB and then melting the solder to connect the two. This secures the switch and creates a connection between the PCB and the switch's metal pins. When you press the switch, the signal can now transfer, register as an input, and eventually, trigger an action on your computer.Before attempting to complete this process properly, some research is required. You risk burning the solder, destroying the socket on your PCB, or messing up the switch's pins. Soldering may appear intimidating, but observing video tutorials and practicing with other objects will teach you how to do it correctly and safely.2. HOT SWAP PCBThe second, and far more straightforward method, is to install your switches using a hot swap PCB. You push your switch's pins into pre-installed sockets rather than using a soldering tool and solder. Hot swapping is similar to installing PC components  or Legos; you simply plug and play. It is quick, requires no training, and allows you to easily swap out switches.Glorious Modular Mechanical Keyboards (GMMK) all use hot swap PCBs.  making them the ideal choice for those looking for a simple, intuitive, and customizable keyboard experience.When installing switches into a hot-swap PCB, a softer surface to push against is recommended. Lining up your switch with the socket requires precision, so a softer surface reduces the possibility of bent pins. Furthermore, when removing switches, you should be gentle on the board. Ripping out a switch could result in catastrophic harm to the hot-swap socket.Note: A solder PCB  can be converted to a hot-swap PCB, but this still necessitates the use of a soldering tool. Furthermore, it is not a simple procedure that we recommend for beginners. Ⅱ Custom Keyboard  - Hotswap vs. Solderable PCB  When building a custom mechanical keyboard, one of the most contentious decisions is whether to use a hot swap PCB or a solderable PCB. Is one superior to the other?To that end, we will discuss the benefits and drawbacks of the two PCB options. The short answer is that there is no "better" PCB – it all comes down to personal preference, which is what defines the custom keyboard hobby.2.1 Advantages of Hotswap PCB  The most significant advantage of using a hotswap PCB  is the ease of switch installation, making it ideal for beginners. Simply ensure that the two pins of a switch are straight, install it to the PCB, and you're ready to go! You are not required to solder each individual switch to the PCB.Another reason why a hotswap PCB  is ideal for newcomers to the pastime is that it allows them to experiment with different switches in real-time. When you're new to the hobby, it's essential to figure out what kind of switch you like and don't like, and a hotswap PCB  makes this stage of...discovery easier.Aside from that, a hotswap PCB  simplifies keyboard tuning and maintenance. Assume you've been using your keyboard for a couple of years and you need to re-lube your switches – yes, you do need to re-lube your switches after some time.With a hotswap PCB.  you can simply remove the switches from your keyboard without having to desolder them.Tuning your stabilizers with a hotswap PCB is also not as difficult, assuming you use screw-in stabilizers. The issue is that you usually have to completely disassemble your keyboard to get to the screw-in stabilizers. Every component attached to the PCB, including the switches and plate, must be removed.While you may have fine-tuned your stabilizers during assembly, they may begin to tick later on. To be sure, you can inject lube directly into the stabilizer housing to try to solve the problem, but this doesn't always work – in my experience, it usually doesn't.2.2 Disadvantages of Hotswap PCB  You're stuck with only one layout if you use a hotswap PCB right away. Of course, some keyboards, such as the Ikki68 Aurora, provide slightly more layout options, but they still fall short of the sheer flexibility of a solderable PCB in this regard. Furthermore, you cannot use a hotswap PCB for half-plate builds. Because the switches are not as "attached" to the PCB as soldered switches are, using a half plate with a hotswap  PCB is not recommended.A half plate, as the name implies, does not cover the alphas on a keyboard. If you use a hotswap PCB with such a plate, the switches in the alphas portion are basically "suspended" without any support from the plate – this can damage a hotswap PCB,  2.3 Advantages of Solderable PCBAs previously stated, a solderable PCB allows you to design your own layout with almost no restrictions. Do you prefer a longer 7u spacebar over a 6.25u spacebar? That's fine. Would you rather have a split backspace than a full backspace? Done.A half plate with a solderable PCB, on the other hand, will provide a softer typing experience. You are typing directly on the PCB because the alphas portion of a half plate is exposed. You'll get a softer, less harsh typing experience if the PCB has flex cuts – a hotswap PCB doesn't have this kind of flexibility.Aside from that, a solderable PCB is less expensive than a hotswap PCB. The price difference isn't particularly significant – about $10 more in most cases – but it's worth noting. However, that is not the entire picture; I'll discuss this further in the following section.2.4 Disadvantages of Solderable PCBEven though a solderable PCB is less expensive than a hotswap PCB. It requires more tools to assemble, such as a soldering iron and desoldering tools. Depending on whether you already have such items, these do increase the "cost of ownership" of a solderable PCB.Assembling a keyboard with a solderable PCB requires more work because each individual switch must be soldered to the PCB. You may even damage the PCB during the assembly process if you are inexperienced with a soldering iron.The inability to easily swap out switches is, in my opinion, the most significant disadvantage of a solderable PCB. This makes a variety of keyboard maintenance tasks more difficult, such as stabilizer tuning, switch relubrication, and troubleshooting any keyboard problems.That's it. You may prefer a hotswap or solderable PCB depending on your preferences. Personally, I always use a hotswap PCB for ease of installation, even if it means I can only do a single layout or a half plate build.In addition, I review keyboard switches  on a regular basis; having a hotswap PCB makes this process much easier.Ⅲ What Is a Hotswap Mechanical Keyboard  ?Hotswap = changing switches without solderingHotswap (also known as hot-swap or hot swap) is a popular feature that Kono Store and Input Club were early adopters of. It refers to keyboards that allow for switch replacement without the use of solder. Kaihua (Kailh), a leading switch manufacturer in China, developed the market-leading hotswap  socket design shown below.How can that get confusing?Many websites state that hotswap keyboards have "hotswap switches," which is rarely the case and can lead to minor confusion. Cherry MX-style hotswap keyboard switches can be used in keyboards with the same hotswap socket pinout/plate design, but they were not designed for hotswap use. These switches can even be soldered into a conventional keyboard. The true innovation is found on the PCB (Printed Circuit Board) or, in the case of actual hotswap switches such as our contactless SILO / Keystone line, in the underlying technology.Ⅳ Why are so few hotswap keyboards available?The most significant reason is a reduction in profit — both long and short term. Hotswap sockets are slightly more expensive per keyboard. Most mass-market keyboards are generated in batches of several thousand or more, so manufacturers don't like the extra cost eating into their profit. They also make repairs very simple; when switches wear out, people are much less likely to purchase a new keyboard rather than repairing it themselves.Implementing hotswap sockets also necessitates some engineering expertise. They take up extra space on the PCB, requiring precise component placement and routing. This limits international layout support at the PCB level, which is especially important if a keyboard includes LEDs. Separate PCB designs are usually required if you want a European enter key or a split space bar in a hotswap keyboard. By reducing LED functionality, keyboards such as the Minivan, which is no longer accessible, achieve partial all-in-one success.Ⅴ How to Make Hot-Swappable Mechanical keyboard PCB  ?Hot-Swappable Sockets for DIY Mechanical Keyboard  With a hot-swappable mechanical keyboard, you can replace switches and LEDs on the fly without soldering or even turning off the keyboard. In this short video tutorial, I demonstrate how to make any printed circuit board for a mechanical keyboard hot-swappable by including footprints for Cherry MX plate switches. Other manufacturers' switches, such as Gateron and Kaihl, are compatible with the Cherry MX switches, making this a universal solution.Required HardwareSuitable printed circuit board (for example for ANAVI Macro Pad 8 maker kit)Switches made of metal3mm LEDs are optional, depending on the type of PCB and switches.KeycapsTE Connectivity / AMP 8134-HC-8P2 Holtite sockets for mechanical switches and TE Connectivity / AMP 8134-HC-5P2 Holtite sockets for 3mm LEDsTweezers, cutters and soldering irons are required tools.Holtite sockets for hot-swap  Step 1Insert the holtite sockets  into the PCB with tweezers . Because the sockets are small, take care not to lose any of them. Switch on the soldering iron. Warm each socket and push it gently. So we're using a soldering iron, but not for soldering. We're just using its heat to mount the sockets.It appears to be simpler than it is. It took some time for me to do it for all of the switches and LEDs. Each key has two holes for the switch and two holes for the LED, so you'll need four sockets of the appropriate size for each key.Step 2The following step is optional and only applies to the ANAVI Macro Pad 8 . The maker kit includes a WS2812B addressable LED strip that should be soldered to the back of the keyboard's side. Please take note of the arrow indicating the direction of the LED strip and ensure you place it correctly as shown in the video.Step 3Cut the legs of the 3mm LEDs  to ensure a good fit in the hot-swappable holtite sockets we've already installed.Step 4Put the switches, LEDs, and keycaps together. After you've completed step 1, this is a simple process since you already get a hot-swappable printed circuit board  for the mechanical keyboard.ANAVI Macro Pad 8 customized with blue Cherry MX switches and green 3mm LEDs for backlightingThe Gateron red switches, red LEDs, and white translucent keycaps that come standard with the ANAVI Macro Pad 8 are standard. In this case, however, I'm experimenting with blue Cherry MX switches, green LEDs, and dark translucent keycaps in the hot-swappable version. I bought a variety of mechanical switches, including Gateron Red, Cherry MX Blue , and Cherry MX Brown. Please keep in mind that the 3mm LED slots on the Cherry MX brown switches in the video are not present.The same method of using holtite sockets can be used on any other mechanical keyboard PCB  with a footprint for Cherry MX switches.Ⅵ Relevant Information about "Hot Swap PCB"1. Are hot-swappable PCBS good?If you're new to mechanical keyboards and not looking to learn how to solder, we recommend a PCB with hot-swap sockets as they are the most beginner friendly.2. Are solder switches hard?Soldering isn't difficult, especially with good tools, but it's still a skill which must be learned and it just doesn't make sense to risk a prized keyboard while you're learning. There are many posts here from folks who have damaged a keyboard with their first soldering attempt and looking for advice on how to fix it.3. What does a soldered PCB mean?PCB soldering is another term for the process of soldering electrical circuit boards. ... As the soldering iron melts this metal, it is then used a bit like glue to stick to pieces together. As the solder metal cools, it will re-harden into one large shape that connects the two parts.4. Can you put 3 pin switches in a 5 pin PCB?There are holes for 5-pin (PCB mount) switches, but 3-pin switches work just fine here since the plate is fastened to the PCB - alignment and stability won't be an issue. This PCB uses good quality Kailh hotswap sockets.5. Does PCB affect sound keyboard?Re: How does the PCB affect the sound of the keyboard? PCB will have minimal effect, despite being connected, it's a soft material and the plate tends to take the actual impact regardless of mount. The plate will change the sound of the ping, but more importantly it can and usually does amplify it.6. What temperature should I solder PCB?600°- 650°F (316°- 343°C) is a good place to start for lead-based solder and 650°- 700°F (343°- 371°C) for lead-free solder. You want the tip hot enough to melt the solder efficiency, but excess heat can damage components as the heat travels along the leads, and it will reduce the lifespan of the soldering tip.7. What are types of PCB?Common Types of Printed Circuit BoardsSingle Layer PCB. Single layer printed circuit boards are among some of the simplest to design and manufacture. ...Double Layer PCB. ...Multi-Layer PCB. ...High Density Interconnect (HDI) PCB. ...High Frequency PCB.8. Is Ducky hot-swappable?All standard Ducky One 3 mechanical keyboards are hot-swappable and feature Kailh's hot-swap sockets. Colored in a vibrant yellow, Kailh sockets are chosen for their impressive reliability.9. Do hot swap keyboards need soldering?All you need to do is just ensure that the two pins of a switch are straight, install it to the PCB, and…you're good to go! You don't have to go through the trouble of soldering each individual switch to the PCB. ... Other than that, a hotswap PCB makes keyboard tuning and maintenance much, much easier as well. 

Introduction In the computer field, a buffer refers to a buffer register, which is divided into two types: input buffer and output buffer. The function of the former is to temporarily store the data sent by the peripheral so that the processor can take it away; the latter is to temporarily store the data sent by the processor to the peripheral. With the numerical control buffer, the high-speed CPU and the slow-speed peripherals can coordinate and buffer to realize the synchronization of data transmission. Since the buffer is connected to the data bus, it must have a three-state output function. Catalog Introduction Ⅰ Three-State Buffer Meaning Ⅱ Buffers in the Java Language 2.1 Buffer 2.2 Data Transmission 2.3 Mark and Reset 2.4 Invariants 2.5 Clear Reverse Rewind 2.6 Read-Only Buffer 2.7 Thread Safety 2.8 Call Chain Ⅲ EDA Code Ⅳ Verilog HDL Model and Simulation of Tri-state Buffer 4.1 Tri-state Buffer IC 4.2 Application Example of 74LS541 as Input Port 4.3 Multiplexer (MUX) Ⅴ FAQ Ⅰ Three-State Buffer Meaning Three-state buffer (tri-state buffer), also known as three-state driver, its three-state output is controlled by the enable output terminal. When the enable output is valid, the device realizes normal logic state output (logic 0, logic 1); when the enable input is invalid, the output is in a high-impedance state, which is equivalent to disconnecting from the connected circuit. Figure 1. Tristate Buffers A buffer is one of the digital components, it does not perform any operation on the input value, and its output value is the same as the input value. It plays an important role in the design of the computer. There are two types of buffers. In addition to tri-state buffers, there are also conventional buffers (regular buffers).Conventional buffers always output the value directly, which is used to output current to higher-level circuitry. The tri-state buffer has an optional card input, denoted by E, in addition to the functions of a conventional buffer. E=0 and E=1 have different output values. Figure 2. Tristate Buffer Symbols When E=1, it is gated, and its input is directly sent to the output.If E=0, the buffer is blocked. No matter what value is input, the output is always high impedance. The high-impedance state can drop the current low enough that the buffer-like output is not connected to anything.In the design of the CPU, the DC load capacity of the general output line can drive a TTL load, and in the connection, an address line or data line of the CPU may be connected to multiple memory chips, but the memory chips are all MOS circuits. It is a capacitive load, and the DC load is much smaller than the TTL load. Therefore, in a small system, the CPU can be directly connected to the memory, but a buffer needs to be added in a large system.In order to reduce the number of information transmission lines, the information transmission lines in most computers are in the form of buses, that is, all the same type of information to be transmitted goes through the same group of transmission lines, and the information is transmitted in time-sharing. There are generally three groups of buses in the computer, namely the data bus, the address bus and the control bus. In order to prevent information from interfering with each other, it is required that any register or memory hung on the bus, etc., its transmission end can not only show two information states of 0 and 1, but also should be able to show a third state-high impedance state. That is, it seems that their outputs are disconnected at this time, which has no effect on the bus state, and the bus can be occupied by other devices at this time. The above functions can be realized. In addition to the input and output terminals, it also has a control terminal, please see the figure below. Figure 3. Three-state Output Buffer Register When E=1, the output=input, the bus is driven by the device at this time, and the data on the bus is determined by the input data.When E=0, the output terminal is in a high-impedance state, and the device has no effect on the bus. When the output terminal of the register is connected to the three-state gate, and then the output terminal of the three-state gate is connected with the bus, the stage-rush register of the three-state output is formed. Since the one-way tri-state gate is used here, the data can only be output from the register to the data bus. If you want to achieve bidirectional transmission, you will use a bidirectional tri-state gate. Figure 4. Three-state Gate Ⅱ Buffers in the Java Language 2.1 Buffer Directly known subclasses of java.nio.Buffer: ByteBuffer, CharBuffer, DoubleBuffer, FloatBuffer, IntBuffer, LongBuffer, ShortBuffer public abstract classBufferextendsObject. A container for data of a specific basic type.A buffer is a linear finite sequence of elements of a particular primitive type. In addition to content, the basic properties of a buffer include capacity, limitation, and location.1) The capacity of a buffer is the number of elements it contains. The capacity of the buffer cannot be negative and cannot be changed.2) The limit of the buffer is the index of the first element that should not be read or written. A buffer's limit cannot be negative and cannot be larger than its capacity.3) The position of the buffer is the index of the next element to be read or written. The buffer's position cannot be negative and cannot be larger than its limit. This class has a subclass for each non-boolean primitive type. 2.2 Data Transmission Each subclass of this class defines two get and put operations:A relative operation reads or writes one or more elements, starting at the current position and incrementing the position by the number of elements transferred. If the requested transfer exceeds the limit, a relative get operation will throw a BufferUnderflowException, and a relative put operation will throw a BufferOverflowException. In both cases, no data is transferred.Absolute operations take explicit element indices, which do not affect position. Absolute get and put operations will throw IndexOutOfBoundsException if the index parameter exceeds the limit. Of course, I/O operations through the appropriate channel (usually related to the current position) can also transfer data to and from the buffer. 2.3 Mark and Reset The mark is an index to which the buffer's position is reset when the reset method is called. It is not always necessary to define a marker, but when defining a marker, you cannot define it as a negative number, and you cannot make it larger than the position. If a marker is defined, it will be discarded when the position or limit is adjusted to a value less than the marker. Calling the reset method will cause an InvalidMarkException to be thrown if the mark is not defined. 2.4 Invariants Mark, position, limit, and capacity values obey the following invariants:0<=mark<=position<=limit<=capacity, newly created buffers always have a 0 position and an undefined mark. The initial limit can be 0 or some other value, depending on the buffer type and how it is built. In general, the initial contents of the buffer are undefined. 2.5 Clear Reverse Rewind In addition to methods for accessing position, limitation, capacity values, and methods for marking and resetting, this class defines the following operations that can be performed on buffers.clear() prepares the buffer for a series of new channel reads or relative put operations. It sets the limit to the capacity size and the position to 0.flip() prepares the buffer for a series of new channel write or relative get operations. It sets the limit to the current position, then the position to 0.rewind() prepares the buffer for rereading already contained data. It leaves the limit unchanged, setting the position to 0. 2.6 Read-Only Buffer Every buffer is readable, but not every buffer is writable. The mutate method of each buffer class is designated as an optional operation and will throw a ReadOnlyBufferException when called on a read-only buffer. A read-only buffer does not allow changes to its contents, but its tag, position, and limit values are mutable. Its isReadOnly method can be called to determine whether the buffer is read-only. 2.7 Thread Safety It is not safe for multiple current threads to use the buffer. If it is used by more than one thread, access to that buffer should be controlled through appropriate synchronization. 2.8 Call Chain Specifies that methods in this class return the buffer on which they were called (otherwise they would return no value). This operation allows method calls to be formed into a chain, like a sequence of statementsb.flip(); b.position(23); b.limit(42); can be replaced by the following short statement b.flip().position(23).limit(42);   Ⅲ EDA Code library ieee;use IEEE.STD_LOGIC_1164.all;ENTITY BUF3S ISPORT (INPUT:IN STD_LOGIC;ENABLE:IN STD_LOGIC;OUTPUT:OUT STD_LOGIC);END BUF3S;ARCHITECTURE BHV OF BUF3S ISBEGINPROCESS(ENABLE,INPUT)BEGINIF ENABLE='1'THEN OUTPUT<=INPUT;ELSE OUTPUT<='Z';END IF;END PROCESS;END BHV;   Ⅳ Verilog HDL Model and Simulation of Tri-state Buffer Figure 5. Verilog HDL Model and Simulation of Tristate Buffer 4.1 Tri-state Buffer IC Tristate buffers are often used for multiple data sources to share a (group) common line (bus). Figure 6. For Multiple Data Sources When all enable terminals of the decoder are valid, the combination of SS2~SS0 makes only one of /SELP~/SELW valid at the same time, so that one of the 8 data sources P~W drives SDATA. When the enable terminal is invalid, then none of the three-state gates are enabled, and the outputs are all high impedance.The MSI device 74LS541 contains 8 independent tri-state gates and shares two enable inputs. The logic diagram and logic symbols are as follows: Figure 7. 74LS541 Logic Diagram and Logic Symbol 4.2 Application Example of 74LS541 as Input Port Figure 8. Application Example of 74LS541 as Input Port The MSI device 74LS245 is an 8-bit tri-state bus transceiver with an enable output G and a direction selection input DIR to determine the transmission direction: when DIR=1, data is transmitted from A to B; when DIR=0, data is transmitted from B passed to A. The logic diagram and logic symbols are as follows: Figure 9. 74LS245 Logic Diagram and Logic Symbol   Figure 10. Bus   Figure 11. Verilog HDL Model of 8-bit Tri-state Bus Transceiver 4.3 Multiplexer (MUX) Multiplexers are also called data selectors, and are often abbreviated as MUX. It is a combinational logic circuit with multiple inputs and single outputs, denoted as n/1 or n-1.Logic function: Since the enable terminal EN is valid., when selecting the control variable, select one of the multiple input data to the output terminal. Figure 12. MUX Each value group of the n selection control variables corresponds to select one of the m=2n input data and then send it to the output terminal.Design of Commonly Used Multiplexers🔺8 to 1 Multiplexer Figure 13. 8 to 1 Multiplexer Function Description   Figure 14. 8 to 1 Logic Circuit Diagram Circuit package, Logic symbol Figure 15. Circuit Package   Figure 16. Logic Symbol 1 Out of 8 Verilog HDL Models Figure 17. 1 Out of 8 Verilog HDL Model   Figure 18. 8 Out of 1 Functional Simulation 🔺8 Out of 1 Multiplexer with Tri--state Output Figure 19. Function Description   Figure 20. 8 to 1 Logic Circuit Diagramof Three-state Output Circuit Package, Logical Symbol Figure 21. 74LS251 Circuit Package and Logical Symbol 1 Out of 8 Verilog HDL Model for Tri-state Output Figure 22. Verilog HDL Model Ⅴ FAQ 1. What is a buffer software?A reserved segment of memory within a program that is used to hold the data being processed. Buffers are set up in every program to hold data coming in and going out. In a video streaming application, the program uses buffers to store an advance supply of video data to compensate for momentary delays. 2. Is buffer safe to use?Buffer is a reliable, fast way to manage multiple social media accounts, from a user-friendly dashboard. 3. Why do we need buffering in OS?Computers have many different devices that operate at varying speeds, and a buffer is needed to act as a temporary placeholder for everything interacting. This is done to keep everything running efficiently and without issues between all the devices, programs, and processes running at that time. 4. Is a buffer hardware or software?A buffer is a data area shared by hardware devices or program processes that operate at different speeds or with different sets of priorities. The buffer allows each device or process to operate without being held up by the other. This term is used both in programming and in hardware. 5. What is tri-state buffer?A tri-state buffer is a logic inverter or a non-inverting buffer with a tri-state output stage. ... When the enable line is not activated the buffer output stage has a high output impedance (i.e., the Z state, as described above in section 10.15) and transmission of data is prevented. 6. What is the difference between buffer and tri-state buffer?A tri-state buffer is similar to a buffer, but it adds an additional "enable" input that controls whether the primary input is passed to its output or not. If the "enable" inputs signal is true, the tri-state buffer behaves like a normal buffer. 7. What is meant by tri-state buffer how it helps in reading and writing data from a register?Definition: A three-state bus buffer is an integrated circuit that connects multiple data sources to a single bus. The open drivers can be selected to be either a logical high, a logical low, or high impedance which allows other buffers to drive the bus. 8. What is tri-state TTL?Tri-state gates have additional circuitry via which the gate outputs can be enabled or disabled. This is very useful in digital systems where devices communicate via common wires called busses. Only one device can talk at a time; the others are disabled. 9. Which of the following is also known as tri-state?Explanation: The progression in the parallel ports provides a third register or an individual control bit which can make the pin in a high impedance state. An output port which can do this is also known as tri-state, that is, logic high, logic low and a high impedance state. 10. What is tri-state in microprocessor?Tristate means three states viz. Logic 0, Logic 1 and high impedance states. In high impedance state, the pin neither connected to supply nor to ground. Hence impedance at this pin is very high with respect to suppy as well as ground. Some pins of 8085 have three states. 11. How many buffer may active at any given time?At any one time, one buffer is actively being displayed by the monitor, while the other, background buffer is being drawn. 12. What is tri-state circuit?Tristate means a digital circuit output that can have 3 states: 0, 1 and High-Z or high impedance which is the circuit equivalent of “disconnected”. There are times when you want to have multiple digital circuits connected on a bus but not interfering with each other.

ⅠIntroductionThyristors are high-speed solid-state devices that can control motors, heaters, and lighting. Before we get into Thyristor Circuits. We'll look at the basic construction and operation of the Silicon Controlled Rectifier, also known as a Thyristor. Next, we'll look at how we can use thyristors and thyristor switching circuits to control much larger loads like lamps, motors, or heaters, among other things. CatalogⅠIntroductionⅡ Thyristors Circuits Related VideoⅢ What Is Silicon Controlled Rectifier?Ⅳ Construction of Silicon Controlled RectifierⅤ What is a Thyristor?Ⅵ Thyristor Switching Circuits6.1 Thyristor Circuit in DC6.2 AC Thyristor CircuitⅦ How an SCR Circuit Works with Thyristor Circuits?7.1 DC Thyristor / SCR Circuit7.2 Basic AC Thyristor / SCR Circuit7.3 AC SCR Circuit with Gate Phase ControlⅧ FAQ Ⅱ Thyristors Circuits Related VideoSilicon Control Rectifier SCR Basic AC Circuit Thyristors Circuits Video Description:  Silicon Control Rectifier SCR Basic AC Circuit Ⅲ What Is Silicon Controlled Rectifier?The Silicon Controlled Rectifier (SCR) is one of the most popular devices in the market. SCR can be found in a variety of applications such as rectification, power regulation, and inversion, among others. SCR, like a diode, is a unidirectional device that allows current in one direction but opposes it in the other gate. SCRs have the ability to turn ON or OFF, and their switching is controlled by biasing conditions and the gate input terminal.By varying the ON periods of the SCR, the average power delivered at the load can be varied. It is capable of handling tens of thousands of voltages and currents. Figure depicts the SCR symbol and its terminals.Figure1 :Silicon Controlled Rectifier   Ⅳ Construction of Silicon Controlled RectifierAs shown in the figure, an SCR has three terminals: anode, cathode, and gate. SCRs have the ability to turn ON or OFF, and their switching is controlled by biasing conditions and the gate input terminal.By varying the ON periods of the SCR, the average power delivered at the load can be varied. It is capable of handling tens of thousands of voltages and currents. Figure depicts the SCR symbol and its terminals.Figure2:Construction The SCR is manufactured using three different types of constructions: planar, Mesa, and press pack. Planar construction, in which all junctions in an SCR are diffused, is used for low-power SCRs. In a mesa type construction, junction J2 is formed by diffusion and the outer layers are alloyed to it as a result. This design is primarily used in high-power Silicon Controlled Rectifiers. The SCR is braced with plates made of molybdenum or tungsten to provide high mechanical strength. One of these plates is soldered to a copper stud, which is threaded to connect to the heat sink. Ⅴ What is a Thyristor?A thyristor is a four-layer solid-state semiconductor device made of P and N materials. When a gate receives a triggering current, it begins to conduct until the voltage across the thyristor device is biased forward. In this case, it functions as a bistable switch. To control a large amount of current flowing through the two leads, we must create a three-lead thyristor by combining the small amount of current with that current. This is referred to as control lead. If the potential difference between the two leads is less than the breakdown voltage, a two-lead thyristor is used to turn the device on.Figure3:Thyristor Ⅵ Thyristor Switching CircuitsDC Thyristor CircuitAC Thyristor circuit 6.1 Thyristor Circuit in DCWhen connected to a DC supply, we use a thyristor to control larger DC loads and current. The main advantage of using a thyristor in a DC circuit as a switch is that it provides a high current gain. Because a small gate current can control a large anode current, the thyristor is classified as a current-operated device.Figure4:Thyristor Circuit in DC 6.2 AC Thyristor CircuitWhen connected to an alternating current supply, the thyristor behaves differently because it is not the same as a DC-connected circuit. A thyristor is used as an AC circuit during one half of a cycle, causing it to turn off automatically due to its reverse biased condition. Figure6:AC Thyristor Circuit Ⅶ How an SCR Circuit Works with Thyristor Circuits?7.1 DC Thyristor / SCR CircuitMany applications call for an SCR circuit to control the operation of a DC load. This can be used for switching DC motors, lamps, or any other load.The basic SCR circuit shown below can control power to a load by using a small switch to initiate power application to the load.Figure7:Basic DC thyristor / SCR circuit With S1 closed and S2 open, no current will flow at first. The SCR circuit will turn on and the current will flow in the load only when S2 is closed and it triggers the gate by causing the gate current to flow.Until the anode circuit is broken, the current will continue to flow. S1 can be used for this. Another method is to place the switch S1 across the SCR and briefly close it, causing the voltage across the SCR to disappear and the SCR to stop conducting.Because of their functions in this SCR circuit, S1 and S2 may be referred to as the Off switch and the ON switch, respectively. In this configuration, S1 must be able to carry the full load current, while S2 must only carry the gate current. Once the SCR is turned on, the switch can be released and remain open because the SCR's action maintains the current flow through the device and thus the load.R1 connects the gate to the power supply via the switch. When S2 is closed, current flows through the resistor enters the gate and activates the SCR. The resistor R1 must be calculated to provide enough gate current to turn on the SCR circuit.R2 is included to reduce the SCR's sensitivity so that it does not fire on any noise that is detected. 7.2 Basic AC Thyristor / SCR CircuitWhen using a thyristor circuit with AC, a few changes must be made, as shown below.This is because alternating current reverses polarity throughout the cycle. This means that the SCR will become reverse-biased, effectively lowering the anode voltage to zero and causing it to turn OFF for one-half of each cycle. As a result, there is no need for an off switch because this is accomplished as part of the use of an alternating current supply.When using a thyristor circuit with AC, a few changes must be made, as shown below.This is because alternating current reverses polarity throughout the cycle. This means that the SCR will become reverse-biased, effectively lowering the anode voltage to zero and causing it to turn OFF for one-half of each cycle. As a result, there is no need for an off switch because this is accomplished as part of the use of an alternating current supply.Figure8: AC thyristor / SCR circuitThe circuit operates in a slightly different manner than the DC SCR circuit. When the switch is turned on, the circuit must wait for sufficient anode voltage to be available as the AC waveform progresses along its path. In addition, the SCR circuit will have to wait until the voltage within the gate section of the circuit is high enough to trigger the SCR. The switch must be in a closed position for this to work.Once triggered, the SCR will remain to conduct for the duration of the positive half of the cycle. As the voltage falls, the anode-cathode voltage will become insufficient to support conduction. At this point, the SCR will come to a halt.The SCR will then not operate during the negative half of the cycle. The process will only be repeated when the next positive half of the cycle returns. As a result, this circuit will only operate when the gate switch is closed.One disadvantage of using this type of SCR circuit is that it cannot supply more than 50% power to the load because it does not conduct during the negative half of the AC cycle because the SCR is reverse biased. 7.3 AC SCR Circuit with Gate Phase ControlBy varying the proportion of the half-cycle over which the SCR conducts, the amount of power reaching the load can be controlled. This can be accomplished by using an SCR circuit with phase control of the input gate signal.Figure9:AC thyristor circuit waveformsThe SCR gate signal is derived from an RC circuit consisting of R1, VR1, and C1 before the diode D1 when using the SCR circuit with phase control.Because the SCR is forward biased, only the positive half cycle of the waveform is of interest, as with the basic AC SCR circuit. During this half-cycle, the capacitor, C1, charges up from the AC supply voltage via the resistor network of R1 and VR1. The waveform at the positive end of C1 is seen to lag behind the input waveform, and the Gate is only triggered when the voltage at the capacitor's high end has risen sufficiently to trigger the SCR via D1. As a result, the SCR's turn-on time is delayed compared to what it would be if the RC network was not present. The VR1 value changes the delay and thus the proportion of the cycle over which the SCR operates. The power into the load can thus be adjusted in this manner. Figure10: AC thyristor circuit with gate phase control R1 is a series resistor that has been included to limit the minimum value for the resistor network to a value that will provide an acceptable gate current level for the SCR. The phase angle of the gate waveform must typically vary between 0° and 180° to provide complete control of the 50% of the cycle available for conduction with an SCR. These circuits demonstrate some of the fundamental concepts underlying the design of SCR thyristor circuits. They show how they work and how they can be used in their most basic form. One of the most important considerations when designing thyristor circuits is power dissipation. Because these circuits frequently handle high voltages and high power levels, power dissipation can be a significant factor in circuit design and operation. Ⅷ FAQ1. What does a thyristor do in a circuit?The primary function of a thyristor is to control electric power and current by acting as a switch. For such a small and lightweight component, it offers adequate protection to circuits with large voltages and currents (up to 6000 V, 4500 A).2. How thyristor acts as a switch?When connected to a direct current DC supply, the thyristor can be used as a DC switch to control larger DC currents and loads. When using the Thyristor as a switch it behaves like an electronic latch because once activated it remains in the “ON” state until manually reset3. What is difference between SCR and thyristor?Thyristor is a four semiconductor layer or three PN junction device. It is also known as “SCR” (Silicon Control Rectifier). The term “Thyristor” is derived from the words of thyratron (a gas fluid tube which works as SCR) and Transistor. Thyristors are also known as PN PN Devices.4. Is thyristor convert AC to DC?A single-phase thyristor rectifier converts an AC voltage to a DC voltage at the output. The power flow is bidirectional between the AC and the DC side.5. What are the advantages of thyristor?Advantages of Thyristor :It is easy to turn on. It is able to control AC power. It can switch high voltage, a high current device. It cost is very low. 

Ⅰ Introduction A flyback converter has the function of a simple switch-mode power supply, which is usually applied in either AC or DC applications. This low- to mid-power device with multiple outputs transfers power from the input to the output during off-time. It can be found in a television set, a plasma lamp, and a variety of other electronic devices that require high voltage.   flyback transformers which I have met with." width="455" height="240" />  6 different kinds of flyback transformers which I have met with   Catalog Ⅰ Introduction Ⅱ Basics of Flyback Transformers 2.1 What are Flyback Transformers? 2.2 What is a flyback? Ⅲ How Does a Flyback Transformer Work? Ⅳ Design of Flyback Transformer 4.1 Key Components of Flyback Transformer 4.2 Design of Flyback Transformer Ⅴ Advantage  and application of Flyback Transformers 5.1 Advantages of Using Flyback Transformers 5.2 What are typical flyback transformer applications? Ⅵ Practical Projects of Flyback Transformers Ⅶ FAQ       Ⅱ Basics of Flyback Transformers   2.1 What are Flyback Transformers?   A flyback transformer is a gapped-core coupled inductor. When the input voltage is applied to the primary winding during each cycle, energy is stored in the gap of the core. It is then transferred to the secondary winding, where it is used to power the load. Flyback transformers are used in flyback converters to provide voltage transformation and circuit isolation.   Flyback transformers are the most common choice for low-cost, high-efficiency isolated power supply designs up to 120 Watts. They offer circuit isolation, the ability to have multiple outputs, and the ability to have positive or negative output voltages. They can also be controlled across a wide range of input voltage and load conditions. Because the energy is stored in the transformer, the flyback topology, unlike the other isolated topologies, does not require a separate output filter inductor. This reduces the number of components required and simplifies the circuit requirements. This article goes over flyback transformers and the applications that they are best suited for. What is a flybackTransformers ?     2.2 What is a flyback?   In the condition of flyback topologies, energy is kept in the magnetic field of the transformer during the first half of the switching cycle, but in the second half of the cycle, it is released to the secondary winding(s) connected to the load. Flyback transformers have a gapped-core design that allows for high energy storage without oversaturating the core. This aspect of energy storage distinguishes flybacks from other topologies such as forward-mode, in which energy is transferred directly from primary to secondary. Flyback transformers are also known as coupled inductors as the gapped core and stored energy.   The circuit of a flyback transformer？       Ⅲ How Does a Flyback Transformer Work?   A flyback transformer circuit resembles other isolated transformer circuits in appearance and has many of the same components, such as a switch, output rectifier or diode, and input and output capacitors. However, compared with other isolated transformers, flyback transformers store energy within the core and do not require a separate output inductor. By ensuring circuit isolation and allowing both positive and negative output voltage, this highly efficient construction facilitates cost-effective power usage.   Switch The metal oxide semiconductor field-effect transistor (MOSFET) is the most common switch design for flyback converters, consisting of three terminals that modify the intensity of and redirect electronic signals. Flyback converter switches can also consist of bipolar transistors, gallium nitride (GaN), or silicon carbide (SiC). Current flows are stored in the core through the primary coil when the switch is closed (or in the on position). When the switch is turned off, current flows through the secondary coil and is transmitted to the output load. The output voltage is adjusted by varying the duty cycles and turn ratios of the primary and secondary coils.   Coupled Inductor A coupled inductor is made up of the coils that transmit and store energy in a flyback transformer. Mutual electromagnetic inductance connects the two coils—when energy flows into the primary coil, it creates a magnetic link and generates a voltage in the second coil. The function of coupled inductors is to change the voltage. They can also be used to isolate circuit components to improve electrical flow efficiency. When the switch is turned on, energy enters the primary winding and is stored in the core. When the switch is in off status, the stored magnetic flux flows into the secondary winding, and the energy is distributed via a diode.   Output Diode As current flows from the second coil, it can be increased, decreased, or modified. Diodes ensure that current flows unidirectionally toward the output and that the voltage remains constant to meet the application's requirements. Because the current from the transformer can fluctuate depending on the input voltage, the diode, and output capacitor help to maintain a constant outflow of current.   Input and Output Capacitors In flyback transformers, capacitors can be installed on both the input and output ends of the current flow. They are used to reserve energy to release it in controlled amounts. Input capacitors manage the flow of energy into the primary coil, while output capacitors manage the flow of energy to ensure a smooth flow at the desired voltage and current.     Fig. 2: Current when switching on and off       Ⅳ Design of Flyback Transformer   4.1 Key Components of Flyback Transformer Primary switchMutually coupled inductorOutput rectifierInput capacitorOutput capacitor     4.2 Design of Flyback Transformer It is made up of a few electrical components. A switching device, consisting of transistors or MOSFETs, is present at the input to turn on and off the primary coil's input voltage. In reverse bias, the secondary coil contains a diode that restricts current flow.       Fig 1. Construction of Flyback transformer   A flyback transformer, unlike other types of transformers, is designed to be excited by direct current voltage. A switch powered by a DC supply drives the primary winding. The magnetic flux is transferred to the secondary coil when the primary coil is activated. Because the secondary coil is connected to a diode in reverse bias., the current is stored. However, As a result, the next incoming primary winding pulse adds to the stored current (i.e the energy stored in the previous pulse). The result of this subsequent addition is a very high pulse of electricity at the output.       Ⅴ Advantage  and application of Flyback Transformers   5.1 Advantages of Using Flyback Transformers Flyback transformers have several advantages over other types of converters, including:   Circuit isolation. The circuit isolation provided by flyback transformers prevents electrical hazards and improves safety, especially for those working near high-energy electrical systems.   Compact size. Flyback transformers are smaller, lighter, and easier to install than comparable transformers due to their simple design, making them a better fit within your overall electrical system.   Cost-effectiveness. Flyback transformers typically cost the same as other transformers. However, because they contain fewer components, flyback converters – of which flyback transformers are an important component – are typically less expensive than comparable converters. This is important to remember when thinking about flyback transformers and their use in flyback converters.   Convenience Flyback transformers can be used to isolate and manipulate multiple output voltages from a single control.     5.2 What are typical flyback transformer applications? Flyback transformers can be used in a variety of applications, including:   DC-DC power suppliesTelecomLED LightingPower over Ethernet (PoE)Capacitor chargingBattery chargingSolar MicroinvertersAC-DC power supplies Flyback transformers are commonly used when the output current is less than 10 amps and the output power is less than 100 watts. Coilcraft sells standard, off-the-shelf flyback transformers ranging in power from a few Watts to around 120 Watts. Forward-mode, push-pull, and half-bridge / full-bridge topologies are more efficient when higher current and power are required.     Ⅵ Practical Projects of Flyback Transformers The drivers used to drive flyback transformers in flyback mode, or push-pull topology, are featured in this project because they are not conventional transformers.   Projects circuit   These flyback transformers can be found in anything with a CRT, such as TVs or monitors, and are responsible for generating high voltage to create an electric field. In turn, electrons are accelerated toward the screen, where they excite phosphors and form images. Flyback transformers are made of coupled inductors that are driven differently than iron-cored main transformers because they use a ferrite core that requires different operating conditions.   building drivers for flyback transformer   To avoid finding the built-in primary, you may need to consider winding your primary during construction. The primary turns can be adjusted to achieve the desired output voltage or drive voltage. The 555 astable modes is used in one flyback driver design.   Ⅶ FAQ 1. What is the function of flyback transformer? A flyback transformers, also known as a line output transformer, stores energy from input voltage in switched-mode power supplies. It is useful for multiple electrical applications. At one time, these transformers were used to meet high voltage needs at high frequencies.   2. Why is it called a flyback transformer? The reason it is called a flyback transformer is because the primary winding uses a relatively low-voltage saw-tooth wave. The wave gets strengthened first and then gets switched off abruptly; this causes the beam to fly back from right to left on the display.   3. What is a flyback transformer in CRT? A flyback transformer, sometimes called a line output transformer, is used in older CRT TV's and computer monitors to produce the high voltage required to drive the CRT and electron gun. They also have auxiliary low voltage windings which the TV designers use to power other parts of the TV.   4. What type of transformer do I have? In order to do this, simply look for the “W” on your device's label. This will help you determine which transformer you need. If the device is 300 watts, then you will need to buy a transformer that is also 300 watts.   5. Why flyback converter is used? Flyback converters are often used in power supplies requiring low to medium output power at several output voltages. With a flyback, multiple outputs incur little additional cost or complexity—each additional output requires only another transformer winding, rectifier and output filter capacitor.   6. How do I select a core for a flyback transformer? The ideal core material should have a maximum available ΔB and low core losses (proportional to the shaded area). Powder cores are made of tiny insulated particles, hence, the air gaps are distributed evenly through the core structure.        

IntroductionIn the lighting industry, people often have a misunderstanding about dimming LED lights. And the reality is that the application of LED light source dimming technology in engineering is often unsatisfactory. Why is this the case? Is the LED light source dimming technology immature, or the technology is difficult to master? So this article analyzes the LED dimmer to help readers to fully understand and master it.Dimming all kinds of LEDs?CatalogIntroductionⅠ Dimming LED Lights1.1 What is Dimming?1.2 LED Dimming Circuit Example1.3 LED Dimming Using SCRⅡ Dimming LED Using PWM2.1 LED Dimming Current2.2 LED PWM Dimmer2.3 LED PWM Dimming Advantages2.4 LED PWM Dimming Problems2.5 DALI PWM Dimmer IntroductionⅢ Main LED Dimmers ComparisonsⅠ Dimming LED Lights1.1 What is Dimming?LED dimmer switch is an electrical device that changes the luminous flux of the light source in the lighting device and adjusts the illuminance level. The purpose of the dimmer is to adjust the different brightness of the light. By reducing or increasing the rms voltage, the light output of different intensities produced by the average power lamp is promoted. Although variable voltage devices can be used for various purposes, this regulation is aimed at controlling lighting. Regarding the LED dimmer switch, we must first understand the volt-ampere characteristics of the LED. That is, the characteristics of the current flowing through the LED PN junction with voltage. Generally, the reverse characteristic curve changes steeply. When the voltage exceeds a certain threshold, the current will rise exponentially, thereby breaking down the LED PN junction. The forward voltage of the LED is also determined by its forward current. It can be seen from the figure that the change of the forward current will cause the corresponding change of the forward voltage, to be precise, the decrease of the forward current will also cause the decrease of the forward voltage. Therefore, when the current is lowered, the voltage of the LED will also decrease, which will change the relationship between the power supply voltage and the load voltage.Figure 1. Diode Volt-Ampere Characteristics CurveTherefore, from the volt-ampere characteristics of the LED, we can know that the dimming of the light source cannot be achieved simply by reducing the input voltage or input current of the LED. In addition, the waveform of the sine wave of the LED is different from the waveform of the incandescent lamp, so it cannot simply change its conduction angle to achieve the purpose of dimming.LED dimming methods can be divided into analog dimming and digital dimming. Analog dimming is to achieve dimming by changing the current in the LED loop. The power supply voltage remains unchanged, and the current in the loop is changed by changing the resistance value to achieve the effect of changing the brightness of the LED. Many analog dimming is an extension of this method. Its advantage is that the current can be continuous, but the range of adjustable current is often limited by hardware, and there are few adjustment gears. This method is not ideal for high-precision lighting equipment.Digital dimming, also known as PWM (Pulse Width Modulation) dimming, uses PWM waves to turn on and off the LED to change the on-time of the forward current to achieve the effect of brightness adjustment. This method is based on the fact that the human eye is not sensitive enough to the brightness flicker. If the frequency of brightness and darkness exceeds 100Hz, the average brightness is seen by the human eye, not the LED flickering. PWM adjusts the brightness by adjusting the ratio of light and dark time. In a PWM cycle, because the perceived brightness of human eyes to flicker is a cumulative process, that is, the brighter time accounts for the greater the proportion of the entire cycle. The longer the time, the brighter the human eye feels.1.2 LED Dimming Circuit ExampleFor example, in an LED lamp with an input of 24V, 8 1W high-power LEDs are connected in series. When the forward current is 350mA, the forward voltage of each LED is 3.3V, then 8 pieces in series is 26.4V, so a constant current source greater than 24V should be used. However, in order to dimming, the current is reduced to 100mA. At this time, the forward voltage is only 2.8V, and 8 pieces are connected in series to 22.4V. The load voltage becomes lower than the input voltage, so that a constant current source larger than 24V cannot work, and finally the LED will flicker.In this case, you may choose a step-down (wide voltage) constant current source, such as a 10V-30V constant current source for dimming. However, if this type is adjusted to a low forward voltage, the LED load current will also become very low. So the step-down ratio is very large, beyond the normal working range of constant current source, which will make LED unable to work and cause flicker. In addition, LED works at low brightness for a long time, which will reduce its efficiency and increase the temperature rise. Because the efficiency of the step-down constant current source is related to the voltage ratio, the larger the voltage drop ratio, the lower the efficiency. And greater power loss on the chip will damage the life of the constant current source and the LED light source.1.3 LED Dimming Using SCROrdinary incandescent lamps and halogen lamps usually use thyristors for dimming. Because they are pure resistance devices, and do not require the input voltage to be a sine wave. Their current waveform is always the same as the voltage waveform, no matter how the voltage waveform deviates from the sine wave, changing the effective value of the input voltage will dim the LED light .However, the adjustment of LED light source by thyristor dimming will cause unexpected problems, that is, the LC filter at the input will cause the thyristor to oscillate. This oscillation is indifferent to the incandescent lamp, human eyes can't see it at all because of thermal inertia. However, this dimming method will cause the driving power of LED produce audio noise and flicker. It will also destroy the waveform of the sine wave, thereby reducing its power factor value (usually lower than 0.5), which greatly reduces the system efficiency of the LED. Moreover, the thyristor dimming waveform increases the harmonic coefficient, and the non-sinusoidal waveform will cause serious electromagnetic interference on the line to pollute the power grid.Ⅱ Dimming LED Using PWM2.1 LED Dimming CurrentHere, you may ask: Lower voltage or current or thyristor dimming methods are not suitable for LED light source dimming, so what is the most suitable method?Is it an analog (0-10V) dimming method? May be not. Analog dimming faces a severe challenge, which is the output current accuracy. Almost every LED driver needs some kind of series resistance to distinguish the current, and the tolerance, offset and delay in the analog (0-10V) dimming drive cause a relatively fixed error, which will reduce the accuracy of the output current, and the final output current cannot be specified, controlled or guaranteed. Therefore, to ensure the dimming effect of the LED light source, one of the important rules is to reduce the output current error and improve the current accuracy in a closed loop system.2.2 LED PWM DimmerThe PWM dimming method can solve the above problems very well. Because diode characteristics, LED can realize fast switching, and its allowable switching speed can be as high as microseconds or more. Therefore, as long as the power supply is changed to a pulse constant current source, the brightness can be changed by PWM. This PWM dimming. This method is like a sluice that opens and closes in microseconds or more. The switching frequency of it is so fast that humans can’t recognize the state of its opening with the naked eye. As a result, people can only identify the speed of its switching frequency by the amount of water downstream. In addition, because the sluice changes the duty cycle of the output water flow (effective water flow), it does not change the instantaneous water pressure and flow rate, so the opening and closing action of the sluice gate will not affect the hydropower generation. The amount of water flowing down and power generation are just changed. Therefore, the PWM dimming method does not change the instantaneous voltage and current of the input LED PN junction, but changes the duty cycle of the output current to change LED brightness.2.3 LED PWM Dimming Advantages1) There will not be any LED chromatogram shift, because the LED always works between the full amplitude current and 0.2) It has a very high dimming accuracy, because the pulse waveform can be controlled to a high precision.3) Even if the light is dimmed in a wide range, there will be no flicker. Because it will not change the working conditions of the constant current source (boost ratio or step-down ratio), problems such as overheating are less to occur.4) It can be combined with digital (DALI/DSI/DMX 512) control technology for control, because the digital control signal can easily be transformed into a PWM signal.2.4 LED PWM Dimming Problems1) Because the LED is in a fast switching state, if the working frequency is very low, the human eye will feel flicker. In order to make full use of the residual visual phenomenon of the human eyes, its operating frequency should be higher than 100Hz, preferably 200Hz.2) Eliminate the howling caused by dimming. Although the human eye can't detect it above 200Hz, it is within the range of human hearing until 20kHz. At this time, it is possible to hear the slightest voice. There are two ways to solve this problem: One is to increase the switching frequency above 20kHz, out of the range of human hearing, another is to find out the sound-producing device and deal with it.At present, some manufacturers have solved the above problems well. A good LED light source dimming technology needs a good LED control signal technology to match and cooperate in order to become an effective, stable and reliable system. For example, the LED PWM dimming method has the advantage that the digital control signal can easily be converted into a PWM signal. At the same time, in the digital control signal of lighting, DALI (Digital Addressable Lighting Interface) has the unparalleled superiority of other lighting digital control methods, and it is also the mainstream of the current digital control application in the lighting industry. Therefore, the matching of PWM dimming mode and DALI takes into account their respective advantages, where PWM dimming technology solves the final dimming problem of LED light sources, and DALI solves the control, feedback and networking of each LED light.Figure 2. LED PWM Dimming Circuit2.5 DALI PWM Dimmer IntroductionThe biggest feature of DALI technology is that each lamp has an independent address. Through the DALI system software, a single lamp or any lamp set can be accurately dimmed and switched, regardless of whether the lamps are on strong current loop or not. That is to say, the lighting control has nothing to do with the strong current circuit. The DALI system software can independently address single or multiple lamps on the same strong current circuit or different circuits, to achieve individual control and arbitrary grouping set. This concept brings great flexibility to lighting control, which can meet different LED lighting requirements. Even after installation, they can still modify the control requirements at will, without having to do anything to the wiring.The following are the application advantages of PWM dimming method combined with DALI.1) The design is simple and easy to implement.In the design, as long as they are connected to each other through the digital signal interface, they are connected in parallel to the 2-core control line. All design process can be programmed by computer software during installation and debugging, which not only saves design costs, but also improve working efficiency.2) Simple and economical installationThe DALI control line has no special requirements for the wire and no polarity requirements during installation. It only requires the main power line to be separated from the control line. The control line does not need to be shielded. When the current on the control line is 250mA and the line is 300 meters long, the drop does not exceed 2V. The control line and the power line can be parallel, no need to bury the line separately. The compact design of the control components does not require a special control cabinet, so installation is simple and economical.3) Simple and convenient operationThe PWM LED driver with DALI control can automatically handle filament preheating, ignition, dimming, switching, fault detection and other functions. The user interface is very friendly. Users can operate and control without deep understanding, such as sending a change. According to the command of the scene, each relevant LED driver calculates the dimming rate according to the difference between the current brightness and the required installation brightness to achieve that all the LED light sources are synchronized to the required scene brightness.4) Accurate and reliable controlDALI is a digital signal, which is different from an analog signal. The signal of 1010 can realize disturbance-free control, and will not distort the control signal due to long-distance voltage drop. Therefore, even if the DALI digital signal control line and the strong wire are in the same line and tube, it will not be disturbed. The DALI signal is two-way transmission, which not only transmits control commands forward, but also feeds back the information of the LED driver's status, fault information, switch, and actual brightness value to the system.5) Wide range of applicationsNowadays, DALI interface is not only used for fluorescent lamp ballast dimming, various electronic transformers for halogen lamps, electronic ballasts for gas discharge lamps. DALI technology also employed in wide range of LED light control makes it more and more widely. Ⅲ Main LED Dimmers Comparisons1) SCR DimmingFigure 3. SCR Dimming Circuit Diagram✅Advantages: It has the advantages of high adjustment accuracy, small size, light weight, easy remote control, etc., which occupies a leading position in the market.❎Disadvantages: The front-cut LED dimmer is prone to generate noise, so it is not recommended for high-demand occasions. The minimum load will vary depending on the LED dimmer and light source. It is necessary to consider derating to adapt to the spike caused by the driver. The typical derating percentage should be 25%-30% of the maximum rated load of the dimmer circuit. 2) CMOS DimmingFigure 4. CMOS Dimming Circuit Diagram✅Advantages: There is no minimum load requirement, so that better performance can be achieved on a single LED lighting device or a very small load.❎Disadvantages: High cost, complicated dimming circuits, lack of high-power products, and poor stability. 3) 0-10V DimmingFigure 5. 0-10V Dimming Circuit Diagram✅Advantages: Simple application, good compatibility, high precision, better dimming effect than phase-cut dimming.❎Disadvantages: Need to add additional control lines and controllers. The dimming effect is related to the wire diameter, cable material, power current, and power supply quantity of 0-10V dimming. 4) DALI DimmingFigure 6. DALI Dimming Circuit Diagram✅Advantages: Accurate and smooth dimming, two-way communication, and strong anti-interference ability, mainly used in single lamp control.❎Disadvantages: Like 0-10V products, additional control circuits and controllers need to be added. 5) DMX512 DimmingFigure 7. DMX512 Dimming Circuit Diagram✅Advantages: Powerful control functions bring rich lighting effects to architectural lighting, night lighting, studios and variety shows.❎Disadvantages: Special wiring layout and types are required, and certain programming is required to set the basic colors and scenes, which is more costly for later maintenance. The ideal transmission distance of DMX signal is less than 200 meters. And meanwhile, in actual use, the signal is greatly interfered by the outside world. 6) SLC and Ready2mains DimmingFigure 8. LED Dimming via Ready2mains✅Advantages: The digital dimming signal is transmitted through the AC wire, without additional signal wires and wiring. Digital signal transmission has good anti-interference performance and excellent dimming effect.❎Disadvantages: At present, there are relatively few products using this type of digital dimming technology, so there are relatively few compatible products. Frequently Asked Questions about LED Dimmer1. What are LED dimmers?An LED dimmer is the term for a device that performs a dimming control operation within such an LED lighting device. LEDs react instantaneously to alterations in power input, making solid state lighting especially suitable for dimming scenarios. 2. Why do my LED dimmer lights flicker?LED bulb flickering can be traced in almost every instance to a non-compatible dimmer switch in the lighting circuit. ... LED bulbs don't have glowing filaments. When the dimmer switch goes off and on many times per second, the LED bulb becomes a flickering strobe light. 3. Do you need a special dimmer for LED lights?Use an LED Dimmer switchA standard dimmer switch cannot be used with an LED light as you will never be able to dim the LED light either completely or not very well. LED lights need their own special electronic dimmer switch to have a fully functioning and dimming light. 4. How do LED dimmer switches work?In the case of PWM, dimmable LEDs work by creating a dimming effect. Unlike traditional lighting such as incandescent, dimmable LED bulbs don't rely on voltage to dictate their level of brightness. Instead, they essentially rely on a cycle of being on and off. 5. What is the best dimmer switch for LED lights?Best Overall: Lutron Toggler Single-Pole/3-Way Light Dimmer.Best Budget: GE Slide Dimmer Rocker Wall Switch, Single Pole.Best Smart: Kasa Smart Dimmer Switch HS220.Best for Bedrooms: Lutron Maestro LED+ Dimmer Switch, Single-Pole or Multi-Location.Best for LED: Lutron Diva LED+ Dimmer Switch, Single-Pole or 3-Way.