Single-chip input voltage protection circuit schematics
The following are the situations related to the input voltage protection circuit schematics of several single-chip processors: ** 1. Diode-based clamp protection circuit ** 1. ** Basic Principles ** - Using the one-way conductivity of the LED to achieve the clamp function. When the input voltage is greater than the voltage, the voltage will be turned on. When the input voltage is less than the voltage, the voltage will be clamped to the voltage. For example, in some circuits, if the input voltage is too high, the acquisition port may be damaged.(For example, the commonly used stm32 single-chip processor, the normal acquisition voltage range is 0 - 3.3V. If the voltage suddenly rises, the voltage of the acquisition port is greater than 5V, which may damage the AD port.) 2. ** Circuit example ** - In some single-chip circuits, when the input voltage of the pin is higher than the voltage of the microchip, the voltage of the microchip is 3.6V or 5V. Since the voltage of the conductor is +0.7V, when the voltage difference between the input pin and the voltage of the microchip is Vpin-Divert>0.7V, the conductor will form a path to limit the input voltage to a certain range. Similarly, when the input voltage of the pin is lower than Vss (generally referred to as ground), when the voltage difference between the input pin and Vss is Vss - Vpin>0.7V, the external input negative voltage signal, the circuit is turned on to form a path. ** II. Protection circuit at the input end (Resistance bi-directional protection circuit)** 1. ** Principle ** - In order to prevent external peak interference and static electricity from damaging the input pins, an anti-pulse circuit could be added to the input to form a resistance bi-directional protection circuit. 2. ** Circuit structure ** - In the input circuit, the input pin of the single-chip processor is connected with a pair of the single-chip processors. ** 3. Circuit to increase the input signal level and convert it (anti-interference for long-line transmission)** 1. ** Principle ** - Considering that the voltage of the TTL level is low, it is easy to be interfered by the outside world in the long-line transmission. The input signal can be increased to +24V, and the high voltage signal is converted into a TTL signal at the entrance of the microchip. This high-voltage transmission method not only improved the noise resistance, but also made the contact of the switch good and reliable. 2. ** Circuit composition ** - In the circuit, the input signal is first connected to a circuit that can withstand a higher voltage. At the entrance of the single-chip, there is a special conversion circuit to convert the +24V signal to a TTL signal. At the same time, there will be a protection circuit (such as a reverse voltage of 50V) to prevent damage to the single-chip from the possible reverse voltage. Read more exciting novels for free
The Principle of the Single-Chip Computer's Automatic Voltage-output Circuit
The following are some principles of voltage output circuits related to single-chip processors: ** 1. Power supply self-locking to open the circuit (Take a circuit as an example)** 1. ** Initial state ** - Before the circuit is powered up, the switch "STAR" is turned off. When the single-chip computer is not powered up, the base of T1 is grounded through R9(100k) and is in the cut-off state. Test and T1, which were connected to the base resistance R7 of T3, were both in the off state, so T3 was also in the off state. At this time, the power supply +9V was isolated by T3 and was not loaded on the voltage regulator chip IC2. The output of IC2 was maintained at a low level. 2. ** Starting Circuit ** - Press the button "Test" to start the circuit. The base of T3 is grounded through R7, Test, and b-e of T2, making T3 turn on. At this time,+9V was added to the voltage stabilizing chip of IC2 through T3, and the output of IC2, VRCC, was added to the single-chip computer. 3. ** Self-locking open ** - After the single-chip computer was working, it would output a high voltage through IO2 and turn on T1 through R8. At this time, even if Test is released, the base of T3 can be grounded through R7, LED1, and T1 to achieve power self-locking. After that, the single-chip software could make the IO2 port turn low again, causing T1 to be turned off, and then T3 to be turned off. ** II. Principle of the direct current step-down circuit (part related to the voltage output of the single-chip computer)** 1. ** Resistance voltage division ** - The simplest way to step down the voltage is to divide the voltage with a resistance, such as the formula [V out = 12> times5> div7 + 5]=5V. However, this method cannot be used with a load. 2. ** Zero-Stabilizer Diode Step-Down ** - The principle was to use the characteristics of the voltage stabilizing circuit, which was cheap and practical. For example, in a series voltage stabilizing circuit, the base of BG was clamped at 13V by the voltage stabilizing device D, and its transmitter output a constant 12V operating voltage. 3. ** Low-voltage-difference linear regulator ** - The circuit is simple, easy to learn and use, and can achieve stable voltage output. 4. ** Switch power supply step-down circuit ** - This kind of circuit had a large voltage drop and a large output power. ** 3. Limiting circuit principle (related to voltage output)** 1. ** Basic limiting circuit ** - In the positive half cycle, when the input voltage is greater than or equal to 0.7V, the positive direction of the circuit is turned on. At this time, the output voltage is clamped at 0.7V. When <VIN> is less than 0.7V, it is in the cut-off state. During the negative half-cycle, it is equivalent to the current reversing, and it is also in the cut-off state. At this time,<VOUT>= VIN>, the <VOUT> wave follows the change of <VIN>>. 2. ** Bias limiting circuit ** - In order to generate different magnitude of the limiting voltage, a bias voltage, VBIAS, was added to the circuit. Only when the voltage was greater than or equal to the voltage, the voltage could be turned on. At this time, VOUT was clamped, and its value was 0.7V+VBIAS. ** 4. Principle of clamp circuit (related to voltage output)** 1. ** Basic clamp circuit (Diode-in-Combination with a Condenser)** - Assuming that the time constant is large enough so that the output wave will not be distorted. When the input is negative in the negative half cycle, the voltage is turned on and the voltage is gradually charged to the voltage. During this process, the voltage is zero. When the input voltage is positive in the positive half cycle, the voltage is cut off, and the voltage is equal to the voltage on the voltage plus the positive half cycle voltage. At this time, the voltage is equal to 2V. 2. ** Bias clamp circuit ** - Similar to the limiting circuit, in order to obtain the required clamp value, a bias voltage was added to the circuit. When the applied bias is in the same direction as the conducting direction of the LED, the clamp value will increase by <<V1>>,<<OUT = 2V +V1>>. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Single chip voltage simulation software
There were some software that could be used to simulate the voltage of the single-chip computer, such as the Simuide, which could not only simulate the circuit but also simulate the AVR single-chip computer. The windows version had the built-in tuning software for the pid single-chip computer. Due to the GPL agreement, the debuggers for the linux-based version needed to be installed. It integrated the Arduino compilation and tuning environment, and the Arduino code could be written and run on it. There were a variety of electronic components in the software that could be freely used. Probes and voltage meters could be added anywhere in the circuit simulation circuit. An ammeter or an earpiece could be used to monitor the voltage and other changes. It could also monitor the memory and register of the single-chip computer. There was also the Proteus software, which was excellent in the simulation of single-chip processors. It supported the simulation of 8051, PAC, and AVR single-chip processors. It could carry out circuit design, circuit board layout and design, circuit simulation parameters analysis, and also support the analysis of various circuit parameters such as voltage. It could also visualize the simulation data through various charts and graphs. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Single-ended input output circuit
Single-ended input and output circuits are a type of differential circuit classified by signal input and output methods. According to the different input and output methods of the signal, the differential circuit was divided into four types: double-ended input and double-ended output, double-ended input and single-ended output, single-ended input and double-ended output, single-ended input and single-ended output. For a single-ended output differential circuit, regardless of the connection method, as long as it is a single-ended output, its amplification factor is half of the basic amplifier circuit; if it is a double-ended output, its amplification factor is the same as the basic amplifier circuit. Single-ended input and output circuits had specific functions and meanings in practical circuit application scenarios. For example, they played a role in circuit designs that required specific amplification or specific circuit connections. At the same time, when the common-mode input (when the two input ends input signals with the same magnitude, it is the common-mode input) and the difference-mode input (when the two input ends input signals with the same magnitude and opposite poles, it is the difference-mode input), the single-ended output will also show different current characteristics. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
single-chip computer subdividing circuit
Microchip micro-circuits have an important application in the control of stepping motor. Taking the two-phase hybrid stepping motor as an example, its subdivision circuit can be constructed by combining integrated chips and separate components, such as the two-phase hybrid stepping motor's self-adapting subdivision drive circuit designed based on the AT89C51 single-chip computer. In the step motor fine control, the fine division technology was a kind of electronic damp technology. The purpose was to improve the operation accuracy of the motor and achieve high-precision fine division of the step angle. For example, in the driving state of two phases and four beats, when the control system does not subdivide, each step pulse motor will rotate an inherent step angle (such as 10°), and when the subdividing driver works in the 10 subdividing state, the motor will only rotate 1°. The subdividing function was achieved by the driver or the single-chip processor by precisely controlling the phase current of the motor, and had nothing to do with the motor itself. There were many factors to consider when constructing a single-chip circuit: 1. ** Power supply related **: Make clear the differences between the labels of different power supplies, such as VRCs, VRCs, and VSSs. For example, VRCs are usually the power supply voltage of a Bipolar device. In an NPM circuit, it represents the power supply voltage connected to the collector. In a field effect circuit, it represents the power supply voltage connected to the drain. In a PPM circuit, it represents the power supply voltage connected to the transmitter. In a circuit with a PPM circuit, it represents the power supply ground or 0V, which is the reference point of the circuit. 2. ** Resistance selection **: - ** Pull-up Resistor **: The choice of the pull-up resistance needs to balance power consumption, driving ability, and circuit speed. In order to reduce power consumption and chip sink current, the resistance value should be as large as possible; in order to ensure sufficient drive current, the resistance value should be as small as possible; in high-speed circuits, an excessively large pull up resistance may make the signal edge smooth, usually between 1k Omega and 10k Omega. In the reset circuit, the resistance value is critical to the start-up of the single-chip computer. For example, when R1 = 10k Omega, it may cause the SSR pin to show a high level, causing the single-chip computer to continue to reset and not work normally. - ** Current limiting resistance **: For example, in an LED circuit, the current limiting resistance should be calculated according to the operating voltage, current range, and circuit voltage of the LED. If the power of the current limiting resistance is not selected properly, there may be problems. For example, in a circuit with an LED voltage drop of 3V, a total voltage of 96V, and a current limiting resistance of 5.1 Ohms, the calculated current is 18ma. However, if the current limiting resistance is 1206, the rated power is 0.25W, and the actual power is 1.7W, the circuit will have problems. 3. ** Condenser application **: There are two types of filter condensers: high frequency and low frequency. The high-frequency filter (usually 0.1 microF) is used to short-circuit the high-frequency noise protection circuit; the low-frequency filter (usually 100 microF) is used to filter out the low-frequency ripple and stabilize the power supply. It is usually installed next to the power interface or high-power components. 4. ** Usage of other components **: - ** Triode **: It has a variety of functions, such as switching function (by controlling the base current to switch between on and off), amplifying function (can amplify the base current by 100 times to drive a larger load), and level conversion function (used for communication between different levels). - ** Nixie tube **: By controlling the seven segments of A - G and the decimal point, it displays the number. It requires a matrix and a truth table to control the brightness of each segment to correspond to a specific number. - ** Key vibration treatment **: The operation of keys will cause vibration, which can be eliminated by software (delay 5 - 10ms after detecting the closed key and wait for the vibration to disappear before confirming the key state) or hardware (use the short-circuit effect of the high-frequency signal by the capacity). When the single-chip I/O port is not enough, the number of ports can be increased by expanding the chip such as the 74HC13838 translator to meet the design requirements of the subdivision circuit. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The Crystal Circuit of 51 Single-Chip Computer
In the 51-bit single-chip computer, the crystal circuit was a crucial part of the peripheral circuit of the single-chip computer. From the perspective of pin connection, the 51 single-chip computer had two pins, XTAL1 and XTAL2, for connecting to the crystal oscillation (crystal resonant). These two pins were connected to an internal phase shifter of the MCUs to form a Pierce Oscillator with the external crystal oscillation. The working principle was that the Pierce Oscillator needed to meet the two conditions of 2k Pi loop phase shift and closed-loop gain of 1 in the ideal circuit form. The phase shifter provides a 180° phase shift for any frequency component and can be seen as a buffer. It is easy to obtain a loop gain of 1 by adjusting its output characteristics. However, this was not enough to start the vibration. The crystal itself was very important. Quartz crystals had a piezo electric effect. After processing, the Quartz Crystal Resonator (QCPR) could be represented by an ideal circuit model consisting of a L1 - C1 - R1 series resonant circuit plus a very small C0. The QPR was connected in parallel with the phase shifter to act as a frequency selection network. When it was powered on, it could be seen as a step signal being input into the output of the phase shifter. The QPR picked out the signal at the resonance point frequency. When the loop gain was 1, the circuit tended to be stable. In the crystal circuit, the common crystal frequencies were 4, 8, 11.0592, 12, etc. The crystal was used to provide a stable clock signal for the single-chip computer. All the instructions of the single-chip computer were based on this. The speed of the single-chip processor was related to the clock frequency provided by the crystal. The higher the clock frequency, the faster the single-chip processor would run. From the composition of the crystal circuit, it was composed of a Quartz crystal and a circuit. Together with the reset circuit, it ensured the stable operation of the single-chip system. The main function of the crystal circuit was to provide clock signals for the operation of various modules within the single-chip computer to ensure the correct execution of the program. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Single-Chip Coupled Circuit Diagram
As for the single-chip coupled circuit, in some electrical control products, the input circuit part involved coupling-related content. For example, when the various control signals of traditional electrical equipment are converted into digital signals that match the input/output port of the single-chip computer, the control signals input by the user equipment to the single-chip computer (such as the switch output of the limit switch, the operation button, etc.) are converted through the input circuit, where the input circuit has a coupling-related function. There was also the circuit diagram of the optical coupler-driven relay in the circuit of the single-chip drive relay. The optical coupler-driven relay played a role in the circuit, but the specific circuit diagram needed to be consulted in special documents, such as the circuit diagram of the optical coupler-driven relay (optical coupler/UL2803/switch circuit) and other related information. In addition, the document on the design method of the commonly used drive and coupled circuit of the single-chip I/O for the characteristics of electrical control products may have more detailed design content about the single-chip coupled circuit, but it did not directly give a detailed circuit diagram. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Measuring voltage and current with a single-chip computer
The following methods can be used to measure voltage and current in the 51 single-chip computer: ** 1. Voltage-measuring ** 1. ** voltage adjustment ** - If the voltage to be measured exceeds the working voltage range of the ADC0809 (8-bit ADC), the voltage to be measured can be reduced to an appropriate range through a resistance voltage splitter circuit to avoid affecting the conversion accuracy. 2. ** Connection and Setting ** - He connected the divided voltage to the input pin of ADC0809 and set the reference voltage. 3. ** Samplings and Conversion ** - The input pin was then subjected to a sample and conversion operation, which resulted in a digital representation of the voltage. 4. ** Conversion of results ** - According to the reference voltage and measurement range of the ADC0809, a suitable formula was determined to convert the obtained digital value into an actual voltage value. ** 2. Current measurement ** 1. ** Current to voltage conversion ** - Using a resistance in series with the current to be measured, according to Ohm's law, the current value can be indirectly obtained by measuring the voltage signal generated at both ends of the resistance. 2. ** Connection and Setting ** - This voltage signal is connected to the input pin of ADC0809. 3. ** Samplings and Conversion ** - The digital representation was obtained by performing a sample and conversion operation. 4. ** Conversion of results ** - The numerical value is converted into an actual current value using a formula related to the measurement range and the reference voltage. During the entire measurement process, it was necessary to pay attention to setting the corresponding operating mode, reference voltage, clock frequency, and other parameters of the ADC0809, and to perform the correct data reading operation. At the same time, due to the limited resolution of the ADC0809, in order to ensure the accuracy and reliability of the measurement results, the stability and anti-interference ability of the circuit should also be paid attention to. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Simulation circuit diagram of the single-chip computer
The following are several examples of simulation circuits related to single-chip processors: - In the ESP32 and Arduino single-chip simulation (such as the website of the website, the simulation circuit that lights up the LED light needs to add an LED light and a current limiting resistance. The negative pole of the LED lamp was connected to the GND pin of the single-chip development board, the positive pole was connected in series with the current limiting resistance, and the other end of the current limiting resistance was connected to the No. 2 pin of the development board. - For the simulation circuit of the steering gear control, add the steering gear in the hardware circuit (the steering gear has three pins, namely, the voltage regulator, the voltage regulator, and the voltage regulator. The voltage regulator is connected to the negative pole of the power supply, and the voltage regulator is connected to the positive pole of the power supply). Then, connect the steering gear to the single-chip computer (if you use the Arduino single-chip computer, you can choose a pin with a "~" to output the voltage regulator signal. In this project, pin 3 is selected as the voltage regulator output pin). - If the simulation uses L298 to drive the direct current motor, the circuit includes the L298N chip (this is a dedicated driver integrated circuit, belonging to the H bridge integrated circuit), the display part uses the PG 160128A (the liquid crystal display dot matrix is 160X128), the input device is a 4X4 matrix keyboard, and it may also include measurement tools such as a virtual scope. The positive and negative rotation of the motor can be controlled by the P1.0 pin of the single-chip computer. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
single-chip dual controllable silicon circuit
This is just a term," single-chip dual controllable silicon circuit." There's no more information, such as its principle, function, application scenarios, etc. Can you give me some additional content? This way, I can make recommendations according to the requirements. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
single-chip control 5v relay circuit
The following are some of the main points of the 5V relay circuit controlled by the single-chip computer: ** 1. In terms of hardware connection ** 1. ** Connection between the pins of the single-chip computer and the relay ** - The output pin of the microchip needed to be connected to the control end of the relay. For example, in a common 51-bit single-chip computer, if the STC89C52 single-chip computer is used, one of its output pins (such as a pin of the P1 port) can be connected to the control input pin of the relay module. Relays generally have two ends of the coil, one end connected to the output pin of the microchip, and the other end connected to the ground or power supply (according to the circuit design of the relay module). 2. ** Power supply ** - The 5V relay required a 5V power supply. You can use the same 5V power supply as the single-chip computer, but pay attention to whether the power of the power supply can meet the needs of both. If the power supply is insufficient, it may cause the relay to not work properly or the single-chip processor to operate unstably. - In order to prevent the relay from interfering with the power supply of the single-chip computer, it may be necessary to consider power isolation. For example, the use of optical isolation or relay driver chips could isolate the power supply of the single-chip processor and the relay to ensure the stability and reliability of the signal transmission. 3. ** Protective Circuit ** - In order to prevent current surges, a suitable current limiting resistance or induction could be added to the control end of the relay. Because the relay may produce a large current impact at the moment of switching, this may affect other components such as the power supply and the single-chip computer. By adding these components, the current can be smoothly controlled. - In order to reduce the electromagnetic interference generated by the relay at the moment of switching on and off, a suitable filter circuit could be added to the control end and power supply end of the relay to limit the transmission of electromagnetic noise. ** 2. Program Control ** 1. ** Initialize ** - In the program of the single-chip computer, the port connected to the control pin of the relay must first be initialized. If you use the C language programming of the 51 single-chip computer, you may need to set the corresponding register to set the control pin to the output mode. For example, when using a pin of the P1 port, the relevant register of the P1 port must be set. 2. ** Control logic ** - When the relay needs to be controlled, the high and low levels are output to the control pin through the single-chip computer program. For example, the output of a high level causes the relay to be pulled in (if the relay is triggered by a high level), and the output of a low level causes the relay to be disconnected. The specific logic needed to be written according to the type of relay (such as high level trigger or low level trigger) and the actual control requirements. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>