The Kynix Components

I. Introduction Ground penetrating radar (GPR) has been widely used in many fields due to its non-destructive detection characteristics. Its detection principle is: use an antenna to transmit high-frequency broadband electromagnetic waves to the ground, and then receive the reflected echo from the interface of the underground medium. Through the processing and analysis of the echo signal, infer the structure of the underground medium. The impact ground penetrating radar has received extensive attention due to its simple structure and rich echo information. The ground penetrating radar mentioned below refers to the impact ground penetrating radar. Due to the sharp loss on the propagation path, the dynamic range of the echo signal received by the antenna is extremely large, generally up to 150dB. The dynamic range of the A/D converter in the radar receiving system can generally only reach 80-90dB, which is difficult to meet the requirements of the radar system. At the same time, due to the small echo amplitude of deep targets, the detection depth and resolution of the ground penetrating radar will be seriously affected if it is not processed. In order to improve the detection depth and resolution of the radar, and at the same time increase the dynamic range of the receiving system, this article uses AD603 to design a time-varying gain amplifier to process the echo signal, and give different gains to the echo signal at different times. To compensate the lack of the dynamic range of the A/D converter, and achieve the purpose of matching the dynamic range of the echo signal. CatalogI. IntroductionII. Design of Time-varying Gain AmplifierIII. Design of the Zero Adjustment Circuit of the Time-varying Gain  AmplifierIV. Measured ResultsV. ConclusionFAQOrdering & Quantity II. Design of Time-varying Gain Amplifier The so-called time-varying gain amplifier simply means that the gain of the amplifier is a function of time. Since in the ground penetrating radar system, time actually corresponds to the distance between the target and the antenna, from this perspective, in the radar system, it can be called a range gain amplifier. The mechanism of action is to use attenuation or lower gain amplification for the scattered echoes of near-distance targets, and use higher gain amplification for the scattered echoes of long-distance targets, so that the echo signals entering the data acquisition circuit become relatively stable. In the end, the strong signal of the shallow target echo is attenuated or suppressed to avoid the amplifier from being saturated and overloaded or the amplifier output exceeds the input range of the A/D converter; the weak signal of the deep target echo is effectively amplified to ensure the acquisition and discernment of the target signal. There are many schemes for designing time-varying gain amplifiers. In view of the requirements of ground penetrating radar system, this article uses the new voltage-controlled amplifier AD603 produced by American Analog Devices to realize the time-varying gain amplifier. The advantages of AD603 are: low noise, wide band, gain, gain range are adjustable, the gain value  changes linearly with the external control voltage, and the bandwidth does not change with the gain, etc., which can fully meet the requirements of the radar system. The schematic diagram is shown in Figure 1.Figure 1 AD603 schematic diagramIt can be seen from the schematic diagram that the internal structure of AD603 is divided into 3 functional areas: gain control area; precision passive input attenuation area; fixed gain operational amplifier area.  The control voltage in the gain control area controls the continuous attenuation of the attenuator. It is like sliding the arrow on the non-inverting end of the fixed gain op amp in the figure between 0 and -42.14dB. The gain range and bandwidth of AD603 are determined by the connection mode of VOUT and FDBK. When VOUT and FDBK are short-circuited, the gain range is 10～30dB, and the bandwidth is 90MHz; when the output terminal VOUT and the feedback terminal FDBK have an indirect 2.15kΩ resistance. When the feedback terminal FDBK is grounded through 5.6pF, the gain range is 0～40dB, frequency bandwidth is 30MHz; when VOUT and FDBK are open, and the feedback terminal FDBK is grounded through 18pF, the gain range is 10-50dB and the frequency bandwidth is 9MHz. Once the gain range is determined, the bandwidth of the entire amplifier is also determined. And within the gain range, the bandwidth does not change with the gain. This is because the gain adjustment is realized by the R-2R ladder resistance attenuation network before the fixed gain op amp, instead of changing the feedback resistance of the op amp, so the bandwidth of the entire amplifier is not affected by the gain adjustment. Since the dynamic range of the ground penetrating radar echo signal is extremely large, in order to provide a larger gain to the weak echo signal in the deep layer, for subsequent data acquisition and processing. In the specific implementation, a two-stage AD603 cascade method is used to realize variable gain amplification, and the gain range of the front and back stages is set to 0-40dB. In this way, the two-stage amplifying circuit can provide a total variable gain range of 0-80dB, which can meet the needs of the ground penetrating radar to expand the dynamic range. At the same time, in order to improve the signal-to-noise ratio of the two-stage amplifier circuit as much as possible and reduce the possibility that the noise generated by the previous amplifier is amplified by the latter amplifier, the two-stage amplifier adopts a sequential control connection method. The circuit principle is shown in Figure 2.Figure 2 Schematic diagram of variable gain amplifier circuitIn order to minimize the frequency band loss after the cascade of the two-stage amplifier, improve the low-frequency response characteristics of the amplifier, and avoid the loss of low-frequency components in the ground penetrating radar echo signal, the direct coupling method is selected in the design. As the gain change range of the single-stage amplifier is set to 0～40dB, its bandwidth is 30MHz. After the two-stage amplifier is cascaded, the total amplifier 3dB bandwidth will be reduced, and the bandwidth at this time is about 21MHz, but the dynamic range is improved. For a ground penetrating radar with an antenna center frequency of 100MHz, the highest frequency component of its echo signal is about 150MHz. Assuming that the transmitted pulse repetition frequency is 300kHz and the sampling time interval is 0.1ns, the highest frequency component of the echo signal after equivalent sampling transformation can be obtained as:It can be seen that the highest frequency component of the signal after sampling and transformation is much smaller than the bandwidth of the amplifier, which can ensure that the signal is amplified without frequency distortion。 After actual measurement, it is found that the maximum amplitude of the echo signal after the equivalent sampling transformation is about ±2.5V, and the maximum allowable input voltage of AD603 is ±1.4V. If the echo signal is directly input, the output signal will be distorted, and the AD603 will be damaged in severe cases, so the input signal must be attenuated first. Because the input impedance of AD603 is 100Q, a 100Q resistor R is connected in series between the input signal and the input of AD603 to form a 1:1 resistor divider to attenuate the input signal. The maximum amplitude of the attenuated signal is about ±1.25V, ensuring that it is within the allowable input voltage range of AD603. Taking into account that in some abnormal situations, the maximum amplitude of the input signal after attenuation is still greater than ±1.4V, so here, D1D2D3D4 diodes are used in series in the same direction, and then connected in anti-parallel between the AD603 input terminal and the analog ground. Using the unidirectional conductivity of the diode and the characteristics of the PN junction forward voltage drop of about 0.7V (for silicon materials), the input signal is limited, and the maximum amplitude of the signal after limiting is exactly about ±1.4V, which satisfies the input voltage requirement of AD603. Based on the same principle, 4 diodes D, D, D, D are used at the input end of the second stage AD603. Limit the signal and limit its amplitude to within ±1.4V. III. Design of the Zero Adjustment Circuit of the Time-varying Gain  Amplifier Since the AD603 has an output offset voltage (DC offset voltage) of about 20-30mV, when the two-pole AD603 is directly coupled, the output offset voltage of the previous AD603 will be amplified by the next AD603. When the gain of the subsequent stage is large, the DC potential of the amplified echo signal will deviate greatly from the zero point, resulting in a part of the upper or lower half of the output signal waveform being cut off, resulting in serious nonlinear distortion. And because the front-stage receiving and sampling gate circuit will also bring a DC offset voltage, that is, the input signal of the first stage AD603 contains a DC offset component, so the DC offset after amplification by the two-stage amplifier circuit will be more serious. Based on the above reasons, a DC offset zeroing circuit must be designed to adjust the DC potential of the output signal, so that no nonlinear distortion is produced when the output signal amplitude reaches the maximum. Because AD603 itself does not have zero adjustment control terminal, so can only add a DC offset zero adjustment circuit before the first stage AD603. In the specific design, an inverting addition amplifier composed of operational amplifiers can be considered. At the inverting input terminal of the operational amplifier, a DC voltage is input through another input loop, and the input echo signal is added to cancel the DC voltage. The offset component will not affect the echo signal itself, so as to achieve the purpose of zeroing the DC offset. Of course, there is another reason for using an op amp to form a DC offset nulling circuit, that is, because the input impedance of AD603 is very low (about 100Q), if it is directly connected to the output of the sample-and-hold circuit of the antenna system, a driving current may appear. The problem of insufficient. The input impedance of the operational amplifier is high, and the output impedance is low. It is connected between the output of the antenna system and the input of AD603, so that the output of the pre-stage sample-and-hold circuit will not be too high, and it can also output a large enough current to drive the AD603, which plays a role of isolation and buffering. The impedance of the level circuit is matched. Figure 3 is a schematic diagram of the DC offset zeroing circuit designed and implemented. The op amp in the picture uses the ultra-low noise, ultra-low distortion operational amplifier AD797 produced by the American Analog Devices company.Figure 3 Schematic diagram of the DC offset zeroing circuit of the variable gain amplifierThere are two adjustment methods for the DC offset zeroing circuit: one is manual adjustment, and the other is automatic adjustment. It should be noted that the zeroing here is different from the zeroing of ordinary op amps. It is no longer for single-stage zeroing, but for multi-stage zeroing, that is, DC potential compensation is performed on the output of the entire amplifier circuit system. In the actual radar system, an automatic adjustment method is used for zero adjustment. The so-called automatic adjustment method is that in the initialization stage before the formal data collection, the computer calculates the DC offset according to the pre-collected echo signal data. Then the offset is sent to a digital-to-analog converter (DAC, digital-to-analog converter), and the converted analog voltage is the DC potential offset compensation voltage required by the DC offset zero circuit. IV. Measured Results Of course, the actual use of the module also includes the design of the active filter and the time-varying gain controller. Due to space reasons, these two modules are not described in detail here. The time-varying gain controller module adopts a design scheme based on DSP and FPGA. The process is as follows: First, set the time-varying gain curve on the PC, and obtain the gain value of each point in an A scan after calculation. Then transfer these gain values ​​as working parameters to the DSP in the radar host through the USB interface. After receiving these parameters, DSP forwards them to FPGA as they are. FPGA then stores these gain values. After the data acquisition starts, the FPGA, under the control of the external synchronization signal, reads out the previously stored gain value in turn, and sends it to the D/A converter for conversion to obtain a time-varying voltage signal. The shape of this signal is basically consistent with the time-varying gain curve set on the PC. Using this signal to control the variable gain amplifier, we can get the time-varying gain we need. In the actual time-varying gain control of ground penetrating radar, two threshold judgment voltages are generally set in advance, that is, set the high threshold voltage to 2V and the low threshold voltage to 1.8V, then if the peak value of the amplified echo signal voltage is greater than 2V, then It is judged that the gain is too high, and the gain is reduced; if the peak value of the amplified echo signal voltage is less than 1.8V, it is judged that the gain is too low and the gain is increased. The time-varying gain amplifier designed with the above design ideas is used in the actual radar prototype. The echo signal after the time-varying gain amplified by the oscilloscope is shown in Figure 4. From the figure, it can be seen that it satisfies As required by the radar system, the amplitude of the echo signal is relatively stable, which ensures the acquisition and identification of the target signal.Figure 4 Echo signal amplified by time-varying gainV. Conclusion This article summarizes the design of the time-varying gain amplifier based on AD603, and gives detailed design ideas and schematic circuit diagrams. The actual test results show that the time-varying gain amplifier designed in the article can meet the needs of radar systems and has strong practical value.FAQWhat is AD603?AD603 is a low-noise, voltage-controlled amplifier for radio frequency (RF) and intermediate frequency (IF) automatic gain control (AGC) systems. It provides precise pin-selectable gain, with a gain range of -11 dB to +31 dB at 90 MHz bandwidth, and a gain range of +9 dB to +51 dB at 9 MHz bandwidth. Any intermediate gain range can be obtained with an external resistor. The noise spectral density referred to the input is only 1.3 nV/√Hz, and the power consumption is 125mW when using the recommended ±5 V power supply.What are the problems that need to be paid attention to when using AD603?The voltage cannot be too high. Generally, the voltage is plus or minus 5V, and the maximum voltage cannot exceed plus or minus 7.5V. The output voltage cannot exceed 2V.How to solve the self-oscillation problem of AD603?For high-frequency operational amplifiers, the following points are the basic ways to solve self-excitation.The power supply is stable and no ripple.The electrical connection wires are as short as possible.The ad603 circuit should be far away from the power circuit, especially away from the transformer.The power transformer and the circuit board of ad603 should be shielded with a metal box and grounded if possible.One point is very important. For op amps, too large magnification can easily cause self-excitation, so reduce the magnification as much as possible and minimize the number of magnification levels (generally not greater than 4).Reverse amplification can suppress self-excitation in multi-stage amplification.If you want to connect to the power amplifier and then amplify, it is best to use two power supplies, and the circuit should be connected to the same ground.What is the difference between AD603AQ and AD603AR?Their differences are in model, Temperature, Package.AD603AQ -40°C to +85°C 8-Lead CERDIPAD603AR -40°C to +85°C 8-Lead SOIC_NAfter inputting an AC signal and being amplified by AD603, why does the output contain a DC signal? How to eliminate the DC signal?When the DC blocking capacitor is not used, the bias voltage of the input circuit needs to be adjusted for compensation.If the DC voltage of the AC signal is not fixed, only a DC blocking capacitor can be used, or the average value can be used to eliminate it after sampling the number.

I IntroductionThe audio power amplifier is a key part of the audio system, which has been widely used in daily life and has strong practicability. However, there is still no suitable voice power amplifier in some occasions. Such as large classrooms for classes, medium-sized conference rooms for meetings, small square gatherings, and other occasions.This blog introduces a simple and low-cost audio amplifier circuit based on NE5532. This circuit overcomes the problem of the high cost of professional equipment and the problem of insufficient power of low-end voice amplifiers on the market. Therefore, it has important research significance for satisfying actual study work.CatalogI IntroductionII System Overall DesignIII System Hardware Design3.1 Band Pass Filter Circuit3.2 Primary Power Amplification3.3 Post-stage Power Amplification3.4 DC Power Supply3.5 Schematic Diagram and Physical Diagram3.6 Test DataIV ConclusionFAQOrdering & QuantityII System Overall DesignThe audio amplifier circuit is mainly composed of the following parts: Band-pass filter circuit; Primary power amplifier circuit;Post-stage power amplifier circuit, DC stabilized power supply;...Its principle block diagram is shown as in Fig. 1.Figure 1. Circuit Block DiagramIII System Hardware Design3.1 Band Pass Filter CircuitThe main function of the band-pass filter circuit is to pre-process the audio signal. This can make it more in line with the requirements of the power amplifier circuit. The band-pass filter circuit uses resistors and capacitors to filter, the effect is stable and easy to debug. It is mainly composed of two parts: channel balance circuit and tone control circuit.The concrete circuit is shown as in Fig. 2.Figure 2. Band Pass Filter Circuit3.1.1 Channel Balance CircuitThe sliding rheostat R1 in Figure 2 acts as an equalizer to balance the size of the left and right channels. The middle pin of the sliding rheostat is connected to the ground and a capacitor C1 is connected in parallel. The function of this capacitor is to filter out high frequency signals in high input audio.3.1.2 Tone Control CircuitThe tone control circuit enables the listener to boost or attenuate certain frequency bands of the sound according to their needs. The multi-band tone circuit used in this blog. In this way, the incoming audio signal enters the middle, low, and high audio control circuit to adjust and then superimposes it into the power amplifier circuit. So that the corrected frequency response is more detailed and the effect is better.(1) Treble ControlThe rheostat R5 and surrounding components form a high-pitched tone circuit. Capacitor C3 can pass high-frequency signals. The treble signal increases when the rheostat slides up, and the treble signal decreases when it slides down.(2) Midrange ControlThe rheostat R8 and surrounding components constitute a mid-tone tuning circuit. Some high-frequency signals in the circuit are filtered out through components such as R7, C4, and R9. C5 can pass intermediate frequency signals in audio. The mid-audio signal increases when the rheostat R8 slides up, and the mid-audio signal decreases when it slides down.(3) Bass ControlThe rheostat R12 and surrounding components form a bass tuning circuit. The audio signal enters R12 to adjust its amplitude. Then, superimpose the adjusted treble and midrange into the power amplifier circuit. In this way, a complete high, middle and low tone circuit can be formed.3.2 Primary Power AmplificationThe primary power amplifier consists of NE5532. NE5532 is a high-performance low-noise dual op amp. It has good noise performance, excellent output drive capability and quite high small signal and power bandwidth. When NE5532 is used for audio amplification, the tone is warm and high fidelity. The circuit is shown in Figure 3.　　Figure 3. Part of NE5532 CircuitHere, the magnification is controlled by R14 and R15. Because there is a post-stage power amplification in the circuit, this stage is amplified to ensure sound quality. We set R14 as 1kΩ and R15 as 10kΩ, which is 10 times. R16 and C8 form a negative feedback circuit. Adjusting R16 and C8 in the circuit can make the sound quality softer, clearer, and more transparent. After repeated debugging, it can be determined that R16 is set to 1MΩ, and C8 is set to 33μF, which achieves their satisfactory results.3.3 Post-stage Power AmplificationThe post-stage power amplifier circuit is composed of two parts: a differential amplifier circuit and a composite tube amplifier circuit. Among them, the composite tube amplifier circuit uses high-power transistor 2N3055. The concrete circuit is shown as in Fig. 4.　Figure 4.  Post-stage Power Amplification3.4 DC Power SupplyThis circuit turns the mains power into a unidirectional direct current through a bridge rectifier circuit. The pulsating component has to go through a filter circuit to become a smooth direct current. Finally, the circuit is stabilized into ±12V direct current through 7812 and 7912 voltage stabilizers and supplied to the load. The power circuit is shown as in Fig. 5.Figure 5. DC Power Supply Circuit3.5 Schematic Diagram and Physical DiagramThe overall schematic diagram and physical diagram of the voice amplifier circuit are shown in Figure 6 and Figure 7.Figure 6. Overall Principle Diagram of Audio Amplifier CircuitFigure 7. Audio Amplifier 3.6 Test DataAfter our repeated debugging of the audio amplifier circuit, we finally achieved a relatively satisfactory effect. The test data is shown in Table 1.Table 1. Test Data of Audio Amplifier CircuitIV ConclusionAfter theoretical analysis and practical testing, the audio amplifier circuit based on NE5532 is simple and stable, with a maximum output power of 40W. Compared with the current mainstream integrated circuit voice amplifier, it has the characteristics of low heat generation, good stability, low cost and high power. Therefore, it has better use value.FAQWhat is NE5532？The NE5532 is a Dual Low Noise Op-Amp in 8-pin package commonly used as amplifiers in audio circuits for its noise immunity and high output drive capability. The Op-Amp is internally compensated for high unity gain with maximum output swing bandwidth, low distortion and high slew rate.How to check NE5532 IC with digital multimeter?Whats the size of NE5532 produced by Texas Instruments? Anything to compare?You will find all physical sizes in inches as well as millimeters in page 19 of the official TI datasheet at:http://www.ti.com/lit/ds/symlink/ne5532.pdfWhat are the features of NE5532?NE5532 is similar to many standard operational amplifiers, but it has the characteristics of better noise performance, excellent output drive capability, high small signal bandwidth, and large power supply voltage range. Therefore, NE5532 is very suitable for high-quality and professional audio equipment, instruments, control circuits and telephone channel amplifiers.What is a key part of the audio system?Audio power amplifierWhat is the problem with NE5532?High cost of professional equipment 

Ⅰ IntroductionA line following car designed with LM393 Voltage Comparator capable of tracking on a specific runway. The line following car mainly includes a solar power supply part and a tracking control part. The control circuit part mainly includes a battery, a switch, first and second light sensitive circuits, a DC motor, a comparison circuit, and a motor drive circuit.This blog test shows that the line following car controlled by the LM393 voltage comparator has the characteristics of high control accuracy, fast start and stop, etc., and solves the problems of the complicated control circuit structure of theline following car and the large deviation of the driving trajectory.CatalogⅠ IntroductionⅡ What is LM393？Ⅲ What is A Line Following Car？3.1 Solar Power Design3.2 Line Following DesignⅣ Circuit Design of Line Following CarⅤ TestⅥ ConclusionFAQOrdering & QuantityⅡ What is LM393？The LM393 offers exceptional value for cost-sensitive applications with a lower offset voltage, higher supply voltage capability, lower supply current, lower input bias current, shorter propagation delay, as well as improved 2 kV ESD performance and input robustness with dedicated ESD clamps.The LM393 devices consist of two independent voltage comparators that are designed to operate from a single power supply over a wide range of voltages. The quiescent current is independent of the supply voltage, and the outputs can be connected to other open-collector outputs to achieve a wired AND relationship.Figure 1. LM393Ⅲ What is A Line Following Car？A line following car is a car that can travel along a preset trajectory. In the process of driving the line following, how to make the car can accurately follow the trajectory without large deviations is the fundamental application of the line following car. However, the existing line following car generally uses the infrared reflection method to feed back the driving trajectory of the car, the control circuit structure is more complicated, and the infrared reflection is easily affected, so not only the cost is higher, but also the driving trajectory of the car is prone to deviation, so it often does not match the design trajectory.Using LM393 voltage comparator as the main control chip of the tracking car will be a better way. Use the resistance change of the photoresistor under the light intensity and the LM393 voltage comparator to control the left and right driving wheels of the car to realize the tracking drive of the car, and cooperate with the display circuit to understand the status of the car. The principle block diagram of line following car based on LM393 voltage comparator is shown in Figure 3.Figure 2. Line Following CarⅣ Circuit Design of Line Following CarThe circuit design of line following car based on LM393 voltage comparator mainly includes solar power supply and car tracking design.The main components of the line following car include a battery box, a control circuit board attached to the bottom of the battery box by double-sided adhesive, and several wheel assemblies installed on both sides of the control circuit board and a solar battery panel installed above the battery box .Figure 3. Block Diagram of Line Following Car3.1 Solar Power DesignThe line following car adopts battery power supply and storage. The solar battery board provides power for the battery, that is, the battery in the car is charged first, and only when the battery has enough power output voltage, the required voltage can be output at the output end of the battery to drive the tracing car.The design of the power supply part mentioned in this blog uses a single lithium battery charging management chip TP4057 with an input voltage of 4V 9V (typical value 5V), which can be used to change the resistance to control the charging current, and its adjustment range is 100mm 500mA and the cut-off voltage is 4.2V.The charging circuit has simple peripherals, no external switch tube is required, and has functions such as charging indication and full indication, anti-reverse battery positive and negative pole reverse connection protection, and power supply undervoltage protection. In addition to using solar panels to power the circuit, it can also work with USB power and adapter power.Figure 4. Schematic Diagram of Charging Circuit3.2 Line Following DesignThe car tracking adopts the LM393 voltage comparator as the control center of the entire tracking circuit. LM393 is a dual voltage comparator integrated circuit, which is composed of two independent precision voltage comparators. Its function is to compare two input voltages and change the level of the output voltage according to the level of the two input voltages. The schematic diagram using the LM393 voltage comparator as the tracking control circuit is shown in Figure 5.This car chooses red LED light as its light source. When the light source shines on white objects and black objects (the predetermined trajectory of the car is black), the reflectivity is different.The light is reflected onto the photoresistor through the ground. When the red LED light is projected on the white area and the black track line, the resistance of the photoresistor will be significantly different because of the different reflectance;By detecting the resistance change of the photoresistor, it can be judged whether the car is driving on the black track line.This car chooses red LED light as its light source. When the light source shines on white objects and black objects (the predetermined trajectory of the car is black), the reflectivity is different. The light is reflected onto the photoresistor through the ground. When the red LED light is projected on the white area and the black track line, the resistance of the photoresistor will be significantly different because of the different reflectance;By detecting the resistance change of the photoresistor, it can be judged whether the car is driving on the black track line.Figure 5. Schematic Diagram of TracingIf the resistance of the photoresistor changes, it means that the white area has been detected, and the car has deviated; at this time, the motor of the left or right wheel of the car is decelerated or even stopped to make the car return to the black track. The track car runs on a similar S-shaped route to achieve the line following function.When there is an imbalance (for example, one wheel is pressed on the black track line), the motor on one side is stopped immediately, and the motor on the other side is accelerated to rotate, so that the car can correct the direction and return to the correct direction. The whole process is a closed loop control, so you can quickly and sensitively control the movement of the line following car.At the same time, the photoresistor can detect the intensity of the external light. The stronger the external light is, the smaller the resistance value of the photoresistor is. The left and right wheel drive of this tracking car uses a DC motor with a reduction gear. The DC motor drives the car to slow down, otherwise the car will run too fast if the speed is too high.Moreover, the torque is too small to run even without deceleration. The motor used in this line following car has integrated a reduction gear to greatly reduce the difficulty of production and debugging. Compared with the use of a single-chip microcomputer as the control circuit, the control circuit composed of the LM393 voltage comparator has a simpler structure, is convenient for assembly and debugging, and has a lower cost.Ⅴ TestFirst of all, place the car on the white background test field of the black track line (the black runway is the car's preset track), and turn on the switches S1, S2, solar panels (or batteries) to provide electricity, so that the voltage comparator controls the start of two DC motors to drive the wheel assemblies on both sides of the car. Our DIY line following car began to drive along the designed track (black runway)!During the driving of the car, the light-emitting diodes D2 and D3 on the left and right sides of the car both emit red light sources. Because the light source irradiates the black runway and the white runway with different reflectivity, and the photoresistor can detect the external light intensity, the stronger the external light, the smaller the photoresistor resistance, the weaker the external light, the greater the resistance.Therefore, when the red LED light is projected onto the black and white runway, because of the different reflectance, the resistance of the photoresistor will be significantly different.Figure 6. Red LEDWhen the light source is reflected by the runway to the photoresistors R14 and R15, the comparator can determine whether the car is driving on the black track line or the white area according to the changes in the resistance of the photoresistors on both sides. And through the diodes and photoresistors on the left and right sides, we can also determine which side the car is deflecting at this time.When an imbalance occurs (for example, the side of the car is pressed against the white area), the DC motor on one side is immediately stopped, and the DC motor on the other side is accelerated to rotate, so that the car can correct the driving direction and return to the correct driving direction (black track on-line.Actually, we can see that the left and right driving wheels of the car rotate in turn and stop driving the car forward; there is a process of deviation, correction, deviation, and correction; but it always advances along the established black trajectory.Ⅵ ConclusionThe solar tracking car discussed in this blog:Passed the test and successfully realized the car's line following;Can be powered by solar energy or battery;Strong stability and anti-interference ability, high control accuracy, fast start and stop;Solved the problems of complicated control circuit of line following car and large deviation of driving trajectory.Using only the LM393 voltage comparator as the controller circuit allows us to assemble and debug conveniently and at a lower cost. The use of non-single chip control is a feature of this line following car.Figure 7. LM393In summary, the line following car based on LM393 control is suitable for technological innovation and technology promotion.FAQWhat is LM393 used for?The LM393 series are dual independent precision voltage comparators capable of single or split supply operation. These devices are designed to permit a common mode range−to−ground level with single supply operation. How does LM393 comparator work?The LM393 is a dual differential comparator; this means that it accepts 2 inputs for comparison. It compares these voltage inputs and determines which is the larger value. Based on this, electronic decisions can be made based on which input is greater and which is smaller. What is the control circuit part of the line following car?A DC motor What is the purpose of the LM393 devices?Wired AND relationship What is a line following car?A car that can travel along a preset trajectory  After reading the blog, have you better understand LM393?  Finally, if you have any questions about LM393, please do not hesitate to leave a message in the comment section below!

Product OverviewLM301 is a general purpose operational amplifier that feature improved performance over industry standards like the LM709. The LM301 IC offers many features which make its application nearly foolproof: Overload protection on the input and output, no latch-up when the common mode range is exceeded, and freedom from oscillations and compensation with a single 30 pF Capacitor. It has advantages over internally compensated amplifiers in that the frequency compensation can be tailored to the particular application. This blog will introduce LM301 systematically from its features, pinout to its specifications, applications, also including LM301 datasheet and so much more. Video: How OpAmps Work - The Learning Circuit CatalogProduct OverviewLM301 FeaturesLM301 PinoutLM301 ApplicationsLM301 Circuit DiagramLM301 SchematicLM301 SpecificationLM301 ManufacturerLM301 DatasheetUsing WarningsLM301 FAQ LM301 FeaturesShort circuit protection and latch free operationSlew rate of 10V/µs as a summing amplifierClass AB output provides excellent linearityLow bias current LM301 PinoutThe following figure is the diagram of LM301 pinout. LM301 Pinout LM301 Pin ConfigurationPin NoPin NameDescription1NULL/COMP 1Null/Compensation Pin 12INV-INPUTInverting Input Pin3NON-INV-INPUTNon Inverting Input Pin4VEEEmitter Supply5OFFSET NULLOffset Null Pin6OUTPUTOutput Pin7VCCCollector Supply Voltage8COMP 2Compensation Pin 2 LM301 ApplicationsUsed in audio automotive designs such as car stereos, radios & Hi-Fi audio setups.Widely used in sound systems such as speakers, high power megaphones, & large scale acoustic systems.An integral part of entertainment systems such as a home theatre setups. LM301 Circuit DiagramFollowing is the circuit diagram of LM301. LM301 Circuit Diagram LM301 Schematic The architecture of LM301 is shown in the picture below. LM301 Schematic LM301 Specificationproduct descritption IC OPAMP GP 1 CIRCUIT 8SOICAmplifier Type General PurposeSlew Rate0.5V/µsCurrent Input Bias70nAVoltage Input Offset 2mVCurrent Supply 1.8mAVoltage – Supply, Single/Dual (±) ±5V ~ 18VOperating Temperature 0°C ~ 70°CMounting Type Surface MountPackage 8-SOIC (0.154″”, 3.90mm Width) LM301 ManufacturerTexas Instruments Incorporated (TI) is a global semiconductor design and manufacturing company that develops analog ICs and embedded processors. By employing the world's brightest minds, TI creates innovations that shape the future of technology. TI is helping more than 100,000 customers transform the future, today. LM301 DatasheetYou can download this datasheet for LM301 – Datasheet from the link given below: LM301 Datasheet Using WarningsNote: Please check their parameters and pin configuration before replacing them in your circuit. LM301 FAQ① When to use the LM101A and lm301a?The LM101A is ensured over a temperature range of −55°C to +125°C, the LM201A from −25°C to +85°C, and the LM301A from 0°C to +70°C. Fast AC-DCConverter Feedforward compensation can be used to make a fast full wave rectifier without a filter. ② What's the difference between Samsung lm301b and LM 301h?According to the data sheet, the LM301H LED has the same electrical and optical characteristics as the LM301B variant. It is available in different colour temperatures from 2200K to 6500K and in colour rendering index CRI 70-90. Another variant with the designation LM301H One is now also available. ③ Which is better fluxengine v2 or lm301h?In fact, a lead of the FLUXengine v2 could be determined in the test. With a current of 1000 mA the sensor of the FLUXengine showed 667 µmol, while the display of the FLUXengine v2 even showed 698 µmol. In addition, the FLUXengine with LM301B dropped a little more voltage, so that the bottom line was a higher efficiency of almost 5%. ④ What is a LM301? A general purpose operational amplifier. ⑤ What is the advantage of LM301?It has advantages over internally compensated amplifiers in that the frequency compensation can be tailored to the particular application.

 This blog covers the pinout, datasheet, specifications and other detailed information of BPW34. The BPW34 is a high speed Photodiode that is commonly used in control and driver circuits. Because of it's short switching time (20nS) it can be used in isolated data communication circuits and other remote communications like TV sets, dimmers and other equipments. Like all photo diode, the BPW34 is normally operated in series with a resistor and the current flowing though it depends on the amount of light falling on it. The intensity of light is measured in luminance. CatalogBPW34 Pin ConfigurationBPW34 FeaturesBPW34 ApplicationsBPW34 Package OutlineBPW34 Technical SpecificationsBPW34 CAD ModelsBPW34 Popularity by RegionBPW34 Market Price AnalysisBPW34 ManufacturerComponent DatasheetOrdering & QuantityBPW34 Pin ConfigurationPin No.Pin NameDescription1AnodePositive Terminal of Phothodiode2CathodeNegative Terminal of PhotodiodeBPW34 FeaturesPackage form: top viewDimensions (L x W x H in mm): 5.4 x 4.3 x 3.2Radiant sensitive area (in mm2): 7.5High photo sensitivityHigh radiant sensitivitySuitable for visible and near infrared radiationFast response timesAngle of half sensitivity: ϕ = ± 65°Compliant to RoHS Directive 2002/95/EC and in accordance to WEEE 2002/96/ECBPW34 ApplicationsPhotointerruptersIndustrial electronicsFor control and drive circuitsIR remote control of hi-fi and TV sets, dimmers, remote controls of various equipmentBPW34 Package Outline BPW34 Technical SpecificationsAttributeAttribute ValueManufacturer:VISHAYProduct Category:Optical Sensors - PhotodiodesProduct:PIN PhotodiodesMounting-Style:Through HolePeak-Wavelength:900 nmDark-Current:2 nAVr-Reverse-Voltage:60 VRise-Time:100 nsFall-Time:100 nsHalf-Intensity-Angle-Degrees:65 degMaximum-Operating-Temperature:+ 100 CMinimum-Operating-Temperature:- 40 CNoise-Equivalent-Power-NEP:4E-14 W/sqrt HzPackaging:TubePd-Power-Dissipation:215 mWPhotocurrent:70 uA BPW34 CAD Models Part Symbol                  FootprintBPW34 Popularity by RegionBPW34 Market Price AnalysisBPW34 ManufacturerVishay Intertechnology was founded in 1962 by Dr. Felix Zandman. It began operations with one technology that had two product lines: foil resistors and foil resistance strain gages. In 1985, having grown from a start-up into the world’s leading manufacturer of these original products, the Company began an ongoing series of strategic acquisitions to become a broadline manufacturer of electronic components. Today, Vishay Intertechnology is one of the world’s largest manufacturers of discrete semiconductors and passive electronic components. These components are used in virtually all types of electronic devices and equipment, in the industrial, computing, automotive, consumer, telecommunications, military, aerospace, power supplies, and medical markets.Component DatasheetBPW34 DatasheetFAQWhat is BPW34?BPW34 is a PIN photodiode with high speed and high radiant sensitivity in miniature, flat, top view, clear plastic package. It is sensitive to visible and near infrared radiation. BPW34S is packed in tubes, specifications like BPW34. What depends on the current flowing on the BPW34?The amount of light falling on it. What is the short switching time of the BPW34?20nS How does BPW34 work?The BPW34 is a tiny, general purpose PiN photodiode. This photodiode has a ton of uses, one of which is to use it is a mini solar cell to power small, low power projects. It is also useful when used as a sensor to detect light. They'll also produce a small voltage, ~250mV, in a brightly, fluorescent-lit room.

CatalogDescriptionCAD ModelsBlock DiagramFeaturesDatasheetSpecificationsManufacturerUsing WarningFAQDescriptionThe STM8S003F3/K3 value line 8-bit microcontrollers offer 8 Kbytes of Flash program memory, plus integrated true data EEPROM. They are referred to as low-density devices in the STM8S microcontroller family reference manual (RM0016). The STM8S003F3/K3 value line devices provide the following benefits: performance,robustness and reduced system cost. Device performance and robustness are ensured by true data EEPROM supporting up to 100000 write/erase cycles, advanced core and peripherals made in a state-of-the-art technology at 16 MHz clock frequency, robust I/Os, independent watchdogs with separate clock source, and a clock security system. CAD Models Figure: PCB Symbol  Figure: Footprint  Figure: 3D Model Block Diagram Figure: Block Diagram FeaturesCore16 MHz advanced STM8 core with Harvardarchitecture and 3-stage pipelineExtended instruction set MemoriesProgram memory: 8 Kbyte Flash memory; data retention 20 years at 55 °C after 100 cyclesRAM: 1 KbyteData memory: 128 bytes true data EEPROM; endurance up to 100 k write/erase cycles Clock, reset and supply management2.95 V to 5.5 V operating voltageFlexible clock control, 4 master clock sources– Low-power crystal resonator oscillator– External clock input– Internal, user-trimmable 16 MHz RC– Internal low-power 128 kHz RCClock security system with clock monitorPower management– Low-power modes (wait, active-halt, halt)– Switch-off peripheral clocks individually– Permanently active, low-consumption power-on and power-down reset Interrupt managementNested interrupt controller with 32 interruptsUp to 27 external interrupts on 6 vectors TimersAdvanced control timer: 16-bit, 4 CAPCOM channels, 3 complementary outputs, dead-time insertion and flexible synchronization16-bit general purpose timer, with 3 CAPCOM channels (IC, OC or PWM)8-bit basic timer with 8-bit prescalerAuto wakeup timerWindow and independent watchdog timers Communications interfacesUART with clock output for synchronous operation, SmartCard, IrDA, LIN master modeSPI interface up to 8 Mbit/sI2C interface up to 400 Kbit/s Analog to digital converter (ADC)10-bit ADC, ± 1 LSB ADC with up to 5 multiplexed channels, scan mode and analog watchdog I/OsUp to 28 I/Os on a 32-pin package including 21 high-sink outputsHighly robust I/O design, immune against current injection Development supportEmbedded single-wire interface module (SWIM) for fast on-chip programming and non-intrusive debugging DatasheetYou can download the datasheet from the link given below.STM8S003F3P6-Datasheet SpecificationsProduct AttributeAttribute ValueManufacturer:STMicroelectronicsProduct Category:8-bit Microcontrollers - MCUSeries:STM8S003F3Mounting Style:SMD/SMTPackage / Case:TSSOP-20Core:STM8Program Memory Size:8 kBData Bus Width:8 bitADC Resolution:10 bitMaximum Clock Frequency:16 MHzNumber of I/Os:16 I/OData RAM Size:1 kBOperating Supply Voltage:2.95 V to 5.5 VMinimum Operating Temperature:- 40 CMaximum Operating Temperature:+ 85 CPackaging:TubeBrand:STMicroelectronicsData RAM Type:RAMData ROM Size:128 BData ROM Type:EEPROMInterface Type:I2C, SPI, UARTNumber of ADC Channels:5 ChannelNumber of Timers/Counters:3 TimerProcessor Series:STM8SProduct Type:8-bit Microcontrollers - MCUProgram Memory Type:FlashFactory Pack Quantity:1480Subcategory:Microcontrollers - MCUSupply Voltage - Max:5.5 VSupply Voltage - Min:2.95 VUnit Weight:0.007055 oz ManufacturerSTMicroelectronics is a French-Italian multinational electronics and semiconductors manufacturer headquartered in Plan-les-Ouates near Geneva, Switzerland. The company resulted from the merger of two government-owned semiconductor companies in 1987: "Thomson Semiconducteurs" of France and "SGS Microelettronica" of Italy. It is commonly called "ST", and it is Europe's largest semiconductor chip maker based on revenue. While STMicroelectronics corporate headquarters and the headquarters for EMEA region are based in the Canton of Geneva, the holding company, STMicroelectronics N.V. is incorporated in the Netherlands. Using WarningNote: Please check their parameters and pin configuration before replacing them in your circuit. FAQWhat is microcontroller and how it works?Microcontrollers are embedded inside devices to control the actions and features of a product. Hence, they can also be referred to as embedded controllers. They run one specific program and are dedicated to a single task. They are low power devices with dedicated input devices and small LED or LCD display outputs.16 Aug 2018 What is the role of a microcontroller?Microcontroller is a compressed micro computer manufactured to control the functions of embedded systems in office machines, robots, home appliances, motor vehicles, and a number of other gadgets. Why microcontroller is used?Microcontrollers are used in automatically controlled products and devices, such as automobile engine control systems, implantable medical devices, remote controls, office machines, appliances, power tools, toys and other embedded systems.