Multi-channel high-voltage power supply circuit based on PWM control for printer

Abstract

The utility model relates to the technical field of power supply for printer, specifically speaking, a kind of structure is reasonable, and the reliable printer is based on the multi-path high voltage power supply circuit of PWM control, it is characterized in that, be equipped with first high voltage power supply circuit and second high voltage power supply circuit, first high voltage power supply circuit and second high voltage power supply circuit are connected with +5V power supply circuit respectively, high voltage converter, rectifier filter circuit, comparator, sampling feedback circuit, PWM drive circuit are equipped in first high voltage power supply circuit, wherein the output end of PWM drive circuit is connected with the input end of a way of comparator, the output end of comparator is connected with high voltage converter, the output end of high voltage converter is connected with rectifier filter circuit, the signal input end of sampling feedback circuit is connected with the output end of rectifier filter circuit, the output end of sampling feedback circuit is connected with the input end of a way of comparator.

Description

Technical Field

[0001] This utility model relates to the field of printer power supply manufacturing technology, specifically a multi-channel high-voltage power supply circuit for printers based on PWM control that has a reasonable structure and reliable operation. Background Technology

[0002] With the development of electronic technology, electrical equipment has emerged, and the power supply circuits that supply power to these devices need to output stable electrical signals according to their requirements. Existing printer power boards use DC high-voltage power supply circuits that suffer from cumbersome structures and poor output signal stability. Furthermore, they also need to meet the output requirements of multiple high-voltage DC signals. Summary of the Invention

[0003] This invention addresses the shortcomings and deficiencies of existing technologies by proposing a multi-channel high-voltage power supply circuit for printers that features a reasonable structure, stable operation, and is particularly suitable for printer power supplies.

[0004] This utility model achieves its purpose through the following measures:

[0005] A multi-channel high-voltage power supply circuit for a printer based on PWM control is characterized by comprising a first high-voltage power supply circuit and a second high-voltage power supply circuit, both of which are connected to a +5V power supply circuit. The first high-voltage power supply circuit includes a high-voltage converter, a rectifier and filter circuit, a comparator, a sampling feedback circuit, and a PWM drive circuit. The output of the PWM drive circuit is connected to one input of the comparator, the output of the comparator is connected to the high-voltage converter, the output of the high-voltage converter is connected to the rectifier and filter circuit, the signal input of the sampling feedback circuit is connected to the output of the rectifier and filter circuit, and the output of the sampling feedback circuit is connected to one input of the comparator.

[0006] The first high-voltage power supply circuit of this utility model is further provided with a constant current overvoltage protection circuit. The input terminal of the constant current overvoltage protection circuit is connected to the output terminal of the rectifier filter circuit, and the output terminal of the constant current overvoltage protection circuit is connected to the output terminal of the sampling feedback circuit, so as to complete the protection of the circuit.

[0007] The second high-voltage power supply circuit of this utility model includes a high-voltage converter, a rectifier and filter circuit, a comparator, a sampling feedback circuit, and a PWM drive circuit. The output terminal of the PWM drive circuit is connected to one input terminal of the comparator, the output terminal of the comparator is connected to the high-voltage converter, the output terminal of the high-voltage converter is connected to the rectifier and filter circuit, the signal input terminal of the sampling feedback circuit is connected to the output terminal of the rectifier and filter circuit, and the output terminal of the sampling feedback circuit is connected to one input terminal of the comparator. The rectifier and filter circuit adopts a half-wave rectifier and filter circuit.

[0008] The PWM drive circuit in the first high-voltage power supply circuit of this utility model includes a MOSFET Q9, which is an N-channel type. The gate (G) of the MOSFET Q9 is connected in series with a resistor R50, and the other end of the resistor R50 is connected to the PWM signal input terminal. The source (S) of the MOSFET Q9 is grounded, and the drain (D) of the MOSFET Q9 is connected to a pull-up resistor R42. The other end of the pull-up resistor R42 is connected to a 5V high potential. A resistor R52A is connected between the resistor R50 and the PWM signal input terminal. Resistors R33 and R43A are connected in series, and the other end of R43A is connected to the + input terminal of the comparator circuit. The other end of the resistor R33 is connected to the drain of the MOSFET. Resistor R26... One end is connected to a +5V high potential, and the other end is connected in series with TRA+ and resistor R34. The other end of resistor R34 is grounded. Capacitor C46 is connected in parallel with resistor R34, and resistor R107 is connected in parallel with capacitor C46. Resistor R33 and resistor R43A are connected to the non-grounded terminal of resistor R34. Resistor R26 and TRA+ are connected in series and then in parallel with resistor R99. The PWM signal is input from one end of resistor R50 and drives the subsequent circuit. The comparator is denoted as IC1. The + input terminal of the comparator is connected to resistor R43A, and the - input terminal of the comparator is connected to resistor R98. The other end of resistor R98 is connected to resistor R9 in the PWM drive circuit. Between resistor R98 and resistor R107, the - input terminal of the comparator is also connected to one end of resistor R108. Resistor R108 is connected in series with capacitor C48, and the other end of capacitor C48 is connected to the output terminal of the comparator. The output terminal of the comparator is connected to the negative terminal of Zener diode ZD2A. When the comparator is working, a comparison voltage is set through resistors R107 and R98 to complete the comparison processing of the electrical signal input to the + input terminal. The high-voltage converter is equipped with a transformer. The primary side of the transformer has two sets of coils, referred to as the first coil and the second coil, respectively. The terminals of the first coil are referred to as terminal 1 and terminal 4, and the terminals of the second coil are referred to as terminal 2 and terminal 4. Pin 3, the two ends of the secondary coil of the transformer are designated as pin 5 and pin 6. The high-voltage converter also includes a transistor Q12, which is an NPN type. The base (B) of transistor Q12 is connected to pin 2, the collector (C) is connected to pin 4, and the emitter (E) is grounded. Resistors R104 and R105 are connected in series to pin 3. Pin 1 is connected to +24V. One end of capacitor C47 is grounded, and the other end is connected between resistors R104 and R105. The other end of resistor R104 is connected to the positive terminal of Zener diode ZD2A. During operation, the first coil is driven by controlling transistor Q12, and the second coil generates a self-oscillating signal to the base of transistor Q12.The rectifier and filter circuit employs a multi-stage rectifier and filter circuit, including a first-stage rectifier and filter circuit composed of diode D11 and capacitor C42, a second-stage rectifier and filter circuit composed of diode D12 and capacitor C40, and a third-stage rectifier and filter circuit composed of diode D10 and capacitor C43. A capacitor C113 is connected in series between pins 5 and 6 of the transformer's secondary side. The first-stage rectifier and filter circuit is connected in parallel with capacitor C113. The second-stage rectifier and filter circuit is connected in parallel with the first-stage rectifier and filter circuit. The third-stage rectifier and filter circuit is connected to the second-stage rectifier and filter circuit. One end of resistor R96 is connected between the negative terminal of diode D10 and capacitor C43 in the third-stage rectifier and filter circuit, and the other end outputs an electrical signal. The sampling feedback circuit includes Zener diodes ZD3 and ZD4, diode D5, and an inductor. The positive terminal of Zener diode ZD3 is connected to the positive terminal of diode D5. 5. The positive terminal of diode D5 is connected to one end of the inductor, and the other end of the inductor is grounded. The negative terminal of Zener diode ZD3 is connected to the + input terminal of the comparator through resistor R43A. The positive terminal of Zener diode ZD4 is connected to the negative terminal of Zener diode ZD3. The negative terminal of Zener diode ZD4 is connected to terminal 6 on the secondary side of the transformer. This is used to sample the output signal of the high-voltage converter and send it into the comparator to complete the feedback. The constant current overvoltage protection circuit includes Zener diode ZD5, diode D81, and capacitor C4. The negative terminal of Zener diode ZD5 is connected to the negative terminal of Zener diode ZD4, and the positive terminal of Zener diode ZD5 is connected to the positive terminal of diode D81. The negative terminal of diode D81 is grounded. One end of capacitor C4 is grounded, and the other end is connected to the negative terminal of Zener diode ZD5. This is used to provide constant current overvoltage protection for the sampling feedback circuit.

[0009] The PWM drive circuit in the second high-voltage power supply circuit of this utility model includes a drive component comprising a MOSFET Q8, which is an N-channel MOSFET. The gate (G) of the MOSFET Q8 is connected in series with a resistor R106, the other end of which is connected to the PWM signal input terminal. The source (S) of the MOSFET Q8 is grounded. The drain (D) of the MOSFET Q8 is connected to a pull-up resistor R28, the other end of which is connected to a 5V high potential. A resistor R32 is connected between the resistor R106 and the PWM signal input terminal, the other end of which is grounded. One end of the pull-up resistor R28 is connected to the drain of the MOSFET Q8, the other end of which is connected to 5V. One end of a resistor R46 is connected to the drain of the MOSFET Q8, and the other end is connected to the input terminal of a comparator. The comparator is denoted as IC1. One end of the resistor R46 is connected to the negative input terminal of IC1. One end of the resistor R71 is connected to 5V, and the other end is connected to a resistor CH+. One end of the resistor CH+ is connected to a resistor… Resistor R51 is connected, with the other end of resistor R51 grounded. One end of resistor R67B is connected to the + input terminal of IC1, and the other end is connected between resistor R51 and resistor CH+. Resistor R84A and capacitor C35 are connected in series and then input to the - input terminal of ICI. The negative terminal of Zener diode ZD6 is connected to the output terminal of IC1, and the positive terminal of Zener diode ZD6 is connected to resistor R62A. Capacitor C35 is connected in series with resistor R84A, with the other end of capacitor C35 connected to the - input terminal of IC1, and resistor R84A connected to the output terminal of IC1. The high-voltage converter includes transformer T6, transistor Q7, and resistor R63A. Transformer T6 has two coils on its primary winding side, labeled as the first coil and the second coil. The terminals of the first coil are labeled as pin 1 and pin 3, and the terminals of the second coil are labeled as pin 2 and pin 4. The terminals of the secondary coil are labeled as pin 5 and pin 6. Resistors R62A and R63A are connected in series. The other end of resistor R63A is connected to pin 4 of transformer T6. Pin 2 of transformer T6 is connected to the base of transistor Q7. The collector of transistor Q7 is connected to pin 3 of transformer T6, and the emitter of Q7 is grounded. The rectifier and filter circuit includes capacitor C119, capacitor C24, and diode D6. And capacitor C25, wherein capacitor C119 is connected between pin 5 and pin 6, capacitor C24 is connected to the negative terminal of diode D6, the other end of capacitor C24 is connected to pin 6, the positive terminal of diode D6 is connected to capacitor C25, and the other end of capacitor C25 is grounded, thus forming a half-wave rectifier circuit to ensure the stability of the output signal; the sampling feedback circuit is provided with resistor R190, one end of resistor R190 is connected to the output terminal of rectifier filter circuit, and the other end is connected to the + input terminal of IC1 through one end of resistor R67B, which is used to sample the output signal of rectifier filter circuit and send it into comparator to complete the feedback.

[0010] In this invention, the output terminal of the high-voltage converter of the second high-voltage power supply circuit is also connected to the input terminal of the rectifier and filter circuit of the first high-voltage power supply circuit, so as to utilize the processing performance of the rectifier and filter circuit in the first high-voltage power supply circuit to improve the stability of the electrical signal output.

[0011] In operation, this invention drives the circuit through two PWM drive signals, PWM1 and PWM2. When the PWM1 control signal is input, the PWM2 control signal is not input. The PWM1 control signal drives the first high-voltage conversion circuit and outputs from the first high-voltage port after rectification and filtering. When the PWM2 control signal is input, the PWM1 control signal is not input. The PWM2 control signal drives the second high-voltage conversion circuit and outputs from the first high-voltage port and the second high-voltage port after rectification and filtering.

[0012] Compared with the prior art, this utility model has significant advantages such as reasonable structure, low cost, and reliable operation. Attached Figure Description

[0013] Appendix Figure 1 This is a structural block diagram of the present invention.

[0014] Appendix Figure 2 This is a circuit schematic diagram of an embodiment of the present invention.

[0015] Figure reference numerals: 1. First high-voltage power supply circuit; 2. Second high-voltage power supply circuit; 3. Power supply circuit; 4. High-voltage converter; 5. Rectifier and filter circuit; 6. Comparator; 7. Sampling feedback circuit; 8. PWM drive circuit; 9. Constant current overvoltage protection circuit. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] As attached Figure 1 As shown, this utility model proposes a multi-channel high-voltage power supply circuit for printers based on PWM control. It includes a first high-voltage power supply circuit 1 and a second high-voltage power supply circuit 2. The first high-voltage power supply circuit 1 and the second high-voltage power supply circuit 2 are respectively connected to a +5V power supply circuit 3. The first high-voltage power supply circuit 1 includes a high-voltage converter 4, a rectifier and filter circuit 5, a comparator 6, a sampling feedback circuit 7, and a PWM drive circuit 8. The output terminal of the PWM drive circuit 8 is connected to one input terminal of the comparator 6, the output terminal of the comparator 6 is connected to the high-voltage converter 4, the output terminal of the high-voltage converter 4 is connected to the rectifier and filter circuit 5, the signal input terminal of the sampling feedback circuit 7 is connected to the output terminal of the rectifier and filter circuit 5, and the output terminal of the sampling feedback circuit 7 is connected to one input terminal of the comparator 6.

[0018] The first high-voltage power supply circuit 1 of this utility model is further provided with a constant current overvoltage protection circuit 9. The input terminal of the constant current overvoltage protection circuit 9 is connected to the output terminal of the rectifier filter circuit 5, and the output terminal of the constant current overvoltage protection circuit 9 is connected to the output terminal of the sampling feedback circuit 7, so as to complete the protection of the circuit.

[0019] The second high-voltage power supply circuit 2 of this utility model includes a high-voltage converter 4, a rectifier and filter circuit 5, a comparator 6, a sampling feedback circuit 7, and a PWM drive circuit 8. The output terminal of the PWM drive circuit 8 is connected to one input terminal of the comparator 6, the output terminal of the comparator 6 is connected to the high-voltage converter 4, the output terminal of the high-voltage converter is connected to the rectifier and filter circuit, the signal input terminal of the sampling feedback circuit 7 is connected to the output terminal of the rectifier and filter circuit 5, and the output terminal of the sampling feedback circuit 7 is connected to one input terminal of the comparator. The rectifier and filter circuit 5 adopts a half-wave rectifier and filter circuit.

[0020] In this invention, the output terminal of the high-voltage converter of the second high-voltage power supply circuit is also connected to the input terminal of the rectifier and filter circuit of the first high-voltage power supply circuit, so as to utilize the processing performance of the rectifier and filter circuit in the first high-voltage power supply circuit to improve the stability of the electrical signal output. Example

[0021] As attached Figure 2As shown, this example provides a multi-output DC high-voltage power supply circuit for a printer, comprising a first high-voltage power supply circuit and a second high-voltage power supply circuit. The PWM drive circuit in the first high-voltage power supply circuit includes a MOSFET Q9, which is an N-channel type. The gate (G) of MOSFET Q9 is connected in series with resistor R50, and the other end of resistor R50 is connected to the PWM signal input terminal. The source (S) of MOSFET Q9 is grounded, and the drain (D) of MOSFET Q9 is connected to a pull-up resistor R42. The other end of pull-up resistor R42 is connected to a 5V high potential. Resistor R52A is connected between resistor R50 and the PWM signal input terminal. Resistors R33 and R43A are connected in series, and the other end of R43A is connected to... The comparator circuit's + input terminal is connected, the other end of resistor R33 is connected to the drain of the MOSFET, one end of resistor R26 is connected to a +5V high potential, and the other end is connected in series with TRA+ and resistor R34, with the other end of resistor R34 grounded. Capacitor C46 is connected in parallel with resistor R34, and resistor R107 is connected in parallel with capacitor C46. The non-grounded terminal of resistor R34 is connected between resistor R33 and resistor R43A. Resistor R26 and TRA+ are connected in series and then in parallel with resistor R99. The PWM signal is input from one end of resistor R50 and drives the subsequent circuits. The comparator is denoted as IC1, with its + input terminal connected to resistor R43A and its - input terminal connected to resistor R98. The other end of resistor R98 is connected between resistors R99 and R107 in the PWM drive circuit. The - input terminal of the comparator is also connected to one end of resistor R108. Resistor R108 is connected in series with capacitor C48, and the other end of capacitor C48 is connected to the output terminal of the comparator. The output terminal of the comparator is connected to the negative terminal of Zener diode ZD2A. When the comparator is working, a comparison voltage is set through resistors R107 and R98 to complete the comparison processing of the electrical signal input to the + input terminal. The high-voltage converter has a transformer. The primary side of the transformer has two sets of coils, referred to as the first coil and the second coil. The terminals of the first coil are labeled as terminal 1 and terminal 4, and the terminals of the second coil are labeled as terminal 1 and terminal 4, respectively. The terminals of the coil are labeled as terminals 2 and 3, and the two terminals of the secondary coil of the transformer are labeled as terminals 5 and 6. The high-voltage converter also includes a transistor Q12, which is an NPN type. The base (B) of transistor Q12 is connected to terminal 2, the collector (C) is connected to terminal 4, and the emitter (E) is grounded. Resistors R104 and R105 are connected in series to terminal 3, and terminal 1 is connected to +24V. One end of capacitor C47 is grounded, and the other end is connected between resistors R104 and R105. The other end of resistor R104 is connected to the positive terminal of Zener diode ZD2A. During operation, the first coil is driven by controlling the operation of transistor Q12, and the second coil generates a self-oscillating signal to the base of transistor Q12.The rectifier and filter circuit employs a multi-stage rectifier and filter circuit, including a first-stage rectifier and filter circuit composed of diode D11 and capacitor C42, a second-stage rectifier and filter circuit composed of diode D12 and capacitor C40, and a third-stage rectifier and filter circuit composed of diode D10 and capacitor C43. A capacitor C113 is connected in series between pins 5 and 6 of the transformer's secondary side. The first-stage rectifier and filter circuit is connected in parallel with capacitor C113. The second-stage rectifier and filter circuit is connected in parallel with the first-stage rectifier and filter circuit. The third-stage rectifier and filter circuit is connected to the second-stage rectifier and filter circuit. One end of resistor R96 is connected between the negative terminal of diode D10 and capacitor C43 in the third-stage rectifier and filter circuit, and the other end outputs an electrical signal. The sampling feedback circuit includes Zener diodes ZD3 and ZD4, diode D5, and an inductor. The positive terminal of Zener diode ZD3 is connected to the positive terminal of diode D5. 5. The positive terminal of diode D5 is connected to one end of the inductor, and the other end of the inductor is grounded. The negative terminal of Zener diode ZD3 is connected to the + input terminal of the comparator through resistor R43A. The positive terminal of Zener diode ZD4 is connected to the negative terminal of Zener diode ZD3. The negative terminal of Zener diode ZD4 is connected to terminal 6 on the secondary side of the transformer. This is used to sample the output signal of the high-voltage converter and send it into the comparator to complete the feedback. The constant current overvoltage protection circuit includes Zener diode ZD5, diode D81, and capacitor C4. The negative terminal of Zener diode ZD5 is connected to the negative terminal of Zener diode ZD4, and the positive terminal of Zener diode ZD5 is connected to the positive terminal of diode D81. The negative terminal of diode D81 is grounded. One end of capacitor C4 is grounded, and the other end is connected to the negative terminal of Zener diode ZD5. This is used to provide constant current overvoltage protection for the sampling feedback circuit.

[0022] The PWM drive circuit in the second high-voltage power supply circuit includes a drive component comprising a MOSFET Q8, which is an N-channel MOSFET. The gate (G) of Q8 is connected in series with a resistor R106, the other end of which is connected to the PWM signal input. The source (S) of Q8 is grounded, and the drain (D) of Q8 is connected to a pull-up resistor R28, the other end of which is connected to a 5V high potential. A resistor R32 is connected between the resistor R106 and the PWM signal input, the other end of which is grounded. One end of the pull-up resistor R28 is connected to the drain of Q8, the other end of which is connected to 5V. One end of a resistor R46 is connected to the drain of Q8, and the other end is connected to the input of a comparator (IC1). One end of resistor R46 is connected to the negative input of IC1, one end of resistor R71 is connected to 5V, and the other end is connected to resistor CH+. One end of resistor CH+ is connected to resistor R... 51 are connected together. The other end of resistor R51 is grounded. One end of resistor R67B is connected to the + input terminal of IC1, and the other end is connected between resistor R51 and resistor CH+. Resistor R84A and capacitor C35 are connected in series and then input to the - input terminal of ICI. The negative terminal of Zener diode ZD6 is connected to the output terminal of IC1, and the positive terminal of Zener diode ZD6 is connected to resistor R62A. Capacitor C35 is connected in series with resistor R84A, and the other end of capacitor C35 is connected to the - input terminal of IC1. Resistor R84A is connected to the output terminal of IC1. The high-voltage converter includes transformer T6, transistor Q7, and resistor R63A. Transformer T6 has two coils on its primary winding side, labeled as the first coil and the second coil. The terminals of the first coil are labeled as pin 1 and pin 3, and the terminals of the second coil are labeled as pin 2 and pin 4. The terminals of the secondary coil are labeled as pin 5 and pin 6. Resistors R62A and R63A are connected in series. The other end of resistor R63A is connected to pin 4 of transformer T6. Pin 2 of transformer T6 is connected to the base of transistor Q7. The collector of transistor Q7 is connected to pin 3 of transformer T6, and the emitter of Q7 is grounded. The rectifier-filter circuit includes capacitor C119, capacitor C24, diode D6, and... Capacitor C25, wherein capacitor C119 is connected between pins 5 and 6, capacitor C24 is connected to the negative terminal of diode D6, the other end of capacitor C24 is connected to pin 6, the positive terminal of diode D6 is connected to capacitor C25, and the other end of capacitor C25 is grounded, thus forming a half-wave rectifier circuit to ensure stable output signal; the sampling feedback circuit includes resistor R190, one end of which is connected to the output terminal of the rectifier filter circuit, and the other end is connected to the + input terminal of IC1 via one end of resistor R67B, used to sample the output signal of the rectifier filter circuit and send it to the comparator to complete the feedback.

[0023] Compared with the prior art, this utility model has significant advantages such as reasonable structure, low cost, and reliable operation.

Claims

1. A multi-channel high-voltage power supply circuit for a printer based on PWM control, characterized in that, The system includes a first high-voltage power supply circuit and a second high-voltage power supply circuit, both of which are connected to a +5V power supply circuit. The first high-voltage power supply circuit includes a high-voltage converter, a rectifier and filter circuit, a comparator, a sampling feedback circuit, and a PWM drive circuit. The output of the PWM drive circuit is connected to one input of the comparator, the output of the comparator is connected to the high-voltage converter, the output of the high-voltage converter is connected to the rectifier and filter circuit, the signal input of the sampling feedback circuit is connected to the output of the rectifier and filter circuit, and the output of the sampling feedback circuit is connected to one input of the comparator.

2. The multi-channel high-voltage power supply circuit for a printer based on PWM control according to claim 1, characterized in that, The first high-voltage power supply circuit is also provided with a constant current overvoltage protection circuit. The input terminal of the constant current overvoltage protection circuit is connected to the output terminal of the rectifier filter circuit, and the output terminal of the constant current overvoltage protection circuit is connected to the output terminal of the sampling feedback circuit, so as to complete the protection of the circuit.

3. A multi-channel high-voltage power supply circuit for a printer based on PWM control according to claim 1, characterized in that, The second high-voltage power supply circuit includes a high-voltage converter, a rectifier and filter circuit, a comparator, a sampling feedback circuit, and a PWM drive circuit. The output of the PWM drive circuit is connected to one input of the comparator, the output of the comparator is connected to the high-voltage converter, the output of the high-voltage converter is connected to the rectifier and filter circuit, the signal input of the sampling feedback circuit is connected to the output of the rectifier and filter circuit, and the output of the sampling feedback circuit is connected to one input of the comparator. The rectifier and filter circuit is a half-wave rectifier and filter circuit.

4. A multi-channel high-voltage power supply circuit for a printer based on PWM control according to claim 1, characterized in that, The PWM drive circuit in the first high-voltage power supply circuit includes a MOSFET Q9, which is an N-channel type. The gate (G) of MOSFET Q9 is connected in series with resistor R50, and the other end of resistor R50 is connected to the PWM signal input terminal. The source (S) of MOSFET Q9 is grounded, and the drain (D) of MOSFET Q9 is connected to pull-up resistor R42. The other end of pull-up resistor R42 is connected to a 5V high potential. Resistor R52A is connected between resistor R50 and the PWM signal input terminal. Resistors R33 and R43A are connected in series, and the other end of R43A is connected to the + input terminal of the comparator circuit. The other end of resistor R33 is connected to the drain of MOSFET Q9. The circuit consists of a resistor R26 connected to a +5V high potential at one end, and the other end connected in series with TRA+ and resistor R34. The other end of resistor R34 is grounded. Capacitor C46 is connected in parallel with resistor R34, and resistor R107 is connected in parallel with capacitor C46. Resistor R33 and resistor R43A are connected to the non-grounded terminal of resistor R34. Resistor R26 and TRA+ are connected in series and then in parallel with resistor R99. The PWM signal is input from one end of resistor R50 and drives the subsequent circuit. The comparator is denoted as IC1. The + input terminal of the comparator is connected to resistor R43A, and the - input terminal of the comparator is connected to resistor R98. The other end of 98 is connected between resistors R99 and R107 in the PWM drive circuit. The - input terminal of the comparator is also connected to one end of resistor R108. Resistor R108 is connected in series with capacitor C48, and the other end of capacitor C48 is connected to the output terminal of the comparator. The output terminal of the comparator is connected to the negative terminal of Zener diode ZD2A. When the comparator is working, a comparison voltage is set through resistors R107 and R98 to complete the comparison processing of the electrical signal input to the + input terminal. The high-voltage converter is equipped with a transformer. The primary side of the transformer has two sets of coils, referred to as the first coil and the second coil. The terminals of the first coil are designated as terminals 1 and 4, the terminals of the second coil as terminals 2 and 3, and the terminals of the secondary coil of the transformer as terminals 5 and 6. The high-voltage converter also includes a transistor Q12, which is an NPN type. The base (B) of the transistor Q12 is connected to terminal 2, the collector (C) is connected to terminal 4, and the emitter (E) is grounded. Resistors R104 and R105 are connected in series to terminal 3, and terminal 1 is connected to +24V. One end of capacitor C47 is grounded, and the other end is connected between resistors R104 and R105. The other end of resistor R104 is connected to the positive terminal of Zener diode ZD2A.

5. A multi-channel high-voltage power supply circuit for a printer based on PWM control according to claim 2, characterized in that, The first high-voltage power supply circuit employs a multi-stage rectifier and filter circuit, including a first-stage rectifier and filter circuit composed of diode D11 and capacitor C42, a second-stage rectifier and filter circuit composed of diode D12 and capacitor C40, and a third-stage rectifier and filter circuit composed of diode D10 and capacitor C43. A capacitor C113 is connected in series between pins 5 and 6 on the secondary side of the transformer. The first-stage rectifier and filter circuit is connected in parallel with capacitor C113. The second-stage rectifier and filter circuit is connected in parallel with the first-stage rectifier and filter circuit. The third-stage rectifier and filter circuit is connected to the second-stage rectifier and filter circuit. One end of resistor R96 is connected between the negative terminal of diode D10 and capacitor C43 in the third-stage rectifier and filter circuit, and the other end outputs an electrical signal. The sampling feedback circuit includes Zener diodes ZD3 and ZD4, diode D5, and an inductor. The positive terminal of Zener diode ZD3... A Zener diode ZD5 is connected to the positive terminal of a transformer. The negative terminal of the Zener diode ZD5 is connected to one end of an inductor, and the other end of the inductor is grounded. The negative terminal of the Zener diode ZD3 is connected to the + input terminal of the comparator via a resistor R43A. The positive terminal of the Zener diode ZD4 is connected to the negative terminal of the Zener diode ZD3, and the negative terminal of the Zener diode ZD4 is connected to pin 6 on the secondary side of the transformer. This is used to sample the output signal of the high-voltage converter and send it to the comparator to complete the feedback. The constant current overvoltage protection circuit includes a Zener diode ZD5, a diode D81, and a capacitor C4. The negative terminal of the Zener diode ZD5 is connected to the negative terminal of the Zener diode ZD4, and the positive terminal of the Zener diode ZD5 is connected to the positive terminal of the diode D81. The negative terminal of the diode D81 is grounded. One end of the capacitor C4 is grounded, and the other end is connected to the negative terminal of the Zener diode ZD5. This is used to provide constant current overvoltage protection for the sampling feedback circuit.

6. A multi-channel high-voltage power supply circuit for a printer based on PWM control according to claim 1, characterized in that, The PWM drive circuit in the second high-voltage power supply circuit includes a drive component comprising a MOSFET Q8, which is an N-channel MOSFET. The gate (G) of Q8 is connected in series with a resistor R106, the other end of which is connected to the PWM signal input. The source (S) of Q8 is grounded. The drain (D) of Q8 is connected to a pull-up resistor R28, the other end of which is connected to a 5V high potential. A resistor R32 is connected between the resistor R106 and the PWM signal input, the other end of which is grounded. One end of the pull-up resistor R28 is connected to the drain of Q8, the other end of which is connected to 5V. One end of a resistor R46 is connected to the drain of Q8, and the other end is connected to the input of a comparator (IC1). One end of resistor R46 is connected to the negative input of IC1. One end of resistor R71 is connected to 5V, and the other end is connected to resistor CH+. One end of resistor CH+ is connected to... Resistor R51 is connected, with the other end of resistor R51 grounded. One end of resistor R67B is connected to the + input terminal of IC1, and the other end is connected between resistor R51 and resistor CH+. Resistor R84A and capacitor C35 are connected in series and then input to the - input terminal of ICI. The negative terminal of Zener diode ZD6 is connected to the output terminal of IC1, and the positive terminal of Zener diode ZD6 is connected to resistor R62A. Capacitor C35 is connected in series with resistor R84A, with the other end of capacitor C35 connected to the - input terminal of IC1, and resistor R84A connected to the output terminal of IC1. The high-voltage converter includes transformer T6, transistor Q7, and resistor R63A. Transformer T6 has two coils on its primary winding side, labeled as the first coil and the second coil. The terminals of the first coil are labeled as pin 1 and pin 3, and the terminals of the second coil are labeled as pin 2 and pin 4. The terminals of the secondary coil are labeled as pin 5 and pin 6. Resistors R62A and R63A are connected in series. The other end of resistor R63A is connected to pin 4 of transformer T6. Pin 2 of transformer T6 is connected to the base of transistor Q7. The collector of transistor Q7 is connected to pin 3 of transformer T6, and the emitter of Q7 is grounded. The rectifier and filter circuit includes capacitor C119, capacitor C24, and diode D6. And capacitor C25, wherein capacitor C119 is connected between pin 5 and pin 6, capacitor C24 is connected to the negative terminal of diode D6, the other end of capacitor C24 is connected to pin 6, the positive terminal of diode D6 is connected to capacitor C25, and the other end of capacitor C25 is grounded, thus forming a half-wave rectifier circuit to ensure the stability of the output signal; the sampling feedback circuit is provided with resistor R190, one end of resistor R190 is connected to the output terminal of rectifier filter circuit, and the other end is connected to the + input terminal of IC1 through one end of resistor R67B, which is used to sample the output signal of rectifier filter circuit and send it into comparator to complete the feedback.

7. A multi-channel high-voltage power supply circuit for a printer based on PWM control according to claim 1, characterized in that, The output terminal of the high-voltage converter in the second high-voltage power supply circuit is also connected to the input terminal of the rectifier and filter circuit in the first high-voltage power supply circuit.

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