Direct-current high-voltage power supply circuit

By introducing a high-voltage converter, rectifier filter circuit, comparator, sampling feedback circuit and PWM drive circuit into the printer power supply circuit, combined with a constant current overvoltage protection circuit, the problems of cumbersome structure and unstable output of existing DC high-voltage power supply circuits are solved, and the stability and reliability of the circuit are improved.

CN224233558UActive Publication Date: 2026-05-12SHANDONG NEWCOWITEL ELECTRONIC CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
SHANDONG NEWCOWITEL ELECTRONIC CO LTD
Filing Date
2025-04-27
Publication Date
2026-05-12

AI Technical Summary

Technical Problem

The DC high-voltage power supply circuit used in existing printer power boards has a cumbersome structure and poor output signal stability.

Method used

A DC high-voltage power supply circuit was designed, which includes a high-voltage converter, a rectifier and filter circuit, a comparator, a sampling feedback circuit, and a PWM drive circuit. Combined with a constant current overvoltage protection circuit, an electrical signal is sent to the comparator through the PWM drive circuit. A stable high-voltage DC signal output is achieved through a multi-stage rectifier and filter circuit. The electrical signal comparison feedback is performed through the sampling feedback circuit to improve the reliability and stability of the circuit.

Benefits of technology

The design achieves structural rationality and operational stability of the DC high-voltage power supply circuit, and improves the output stability of electrical signals.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model relates to the technical field of power supply equipment manufacturing, in particular to a direct-current high-voltage power supply circuit which is reasonable in structure, stable in work and particularly suitable for a power supply for a printer, and is characterized by being provided with a high-voltage converter, a rectifying and filtering circuit, a comparator, a sampling feedback circuit and a PWM (Pulse-Width Modulation) driving circuit, wherein the output end of the PWM drive circuit is connected with one input end of the comparator, the output end of the comparator is connected with the high-voltage converter, the output end of the high-voltage converter is connected with the rectification filter circuit, and the signal input end of the sampling feedback circuit is connected with the output end of the rectification filter circuit. The output end of the sampling feedback circuit is connected with one input end of the comparator.
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Description

Technical fields:

[0001] This utility model relates to the field of power supply equipment manufacturing technology, specifically a DC high-voltage power supply circuit with a reasonable structure and stable operation, which is particularly suitable for printer power supplies. 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 DC high-voltage power supply circuits used in printer power boards suffer from cumbersome structures and poor output signal stability; therefore, there is an urgent need for a suitable DC high-voltage power supply circuit for printers. Summary of the Invention:

[0003] This invention addresses the shortcomings and deficiencies of existing technologies by proposing a DC high-voltage power supply circuit with a reasonable structure, stable operation, and particular suitability for printer power supplies.

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

[0005] A DC high-voltage power supply circuit is characterized by comprising a high-voltage converter, a rectifier and filter circuit, a comparator, a sampling feedback circuit, and a PWM drive circuit, wherein 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.

[0006] This utility model also includes 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, which is used to protect the circuit.

[0007] The PWM drive circuit of this invention includes a MOSFET Q9, which is an N-channel MOSFET. The gate (G) of 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 MOSFET Q9 is grounded, and the drain (D) of 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 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. The + input terminal is connected, the other end of resistor R33 is connected to the drain of MOSFET, one end of resistor R26 is connected to +5V high potential, and the other end is connected in series with TRA+ and resistor R34 in sequence. The other end of resistor R34 is grounded, capacitor C46 is connected in parallel with resistor R34, 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, and the PWM signal is input from one end of resistor R50 to complete the driving of subsequent circuits.

[0008] The comparator described in this invention is denoted as IC1. The positive input terminal of the comparator is connected to resistor R43A, and the negative input terminal is connected to resistor R98. The other end of resistor R98 is connected between resistors R99 and R107 in the PWM drive circuit. The negative input terminal of the comparator is also connected to one end of resistor R108. Resistor R108 is connected in series with capacitor C48. 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 at the positive input terminal.

[0009] The high-voltage converter of this utility model includes 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 labeled as terminals 1 and 4, and the terminals of the second coil are labeled as terminals 2 and 3. 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 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. 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 transistor Q12, and the second coil generates a self-oscillating signal to the base of transistor Q12.

[0010] The rectifier and filter circuit described in this utility model adopts 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.

[0011] The sampling feedback circuit of this utility model includes a Zener diode ZD3, a Zener diode ZD4, a diode D5, and an inductor. The anode of Zener diode ZD3 is connected to the anode of diode D5, the cathode of diode D5 is connected to one end of the inductor, and the other end of the inductor is grounded. The cathode of Zener diode ZD3 is connected to the + input terminal of the comparator through resistor R43A. The anode of Zener diode ZD4 is connected to the cathode of Zener diode ZD3, and the cathode of Zener diode ZD4 is connected to pin 6 on the secondary side of the transformer. This circuit samples the output signal of the high-voltage converter and sends it to the comparator to complete the feedback.

[0012] The constant current overvoltage protection circuit of this utility model 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 circuit is used to provide constant current overvoltage protection for the sampling feedback circuit.

[0013] In operation, this invention sends an electrical signal to the comparator via a PWM drive circuit. The other input terminal of the comparator is set with a comparison voltage value. The electrical signal output by the comparator is output through a high-voltage converter and then passes through a multi-stage rectifier and filter circuit to achieve a stable high-voltage DC signal output. During this process, the electrical signal at the output terminal is fed back to the comparator by a sampling feedback circuit to complete the comparison feedback, thereby improving the reliability and stability of the entire circuit.

[0014] Compared with the prior art, this utility model has significant advantages such as reasonable structure and stable operation. Attached image description:

[0015] Appendix Figure 1 This is a structural block diagram of the present invention.

[0016] Appendix Figure 2 This is a circuit schematic diagram of an embodiment of the present invention.

[0017] Figure reference numerals: 1. High voltage converter; 2. Rectifier and filter circuit; 3. Comparator; 4. Sampling feedback circuit; 5. PWM drive circuit; 6. Constant current overvoltage protection circuit. Detailed implementation method:

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] As attached Figure 1 As shown, this utility model proposes a DC high-voltage power supply circuit, which includes a high-voltage converter 1, a rectifier and filter circuit 2, a comparator 3, a sampling feedback circuit 4, and a PWM drive circuit 5. The output terminal of the PWM drive circuit 5 is connected to one input terminal of the comparator 3, the output terminal of the comparator 3 is connected to the high-voltage converter 1, the output terminal of the high-voltage converter 1 is connected to the rectifier and filter circuit 2, the signal input terminal of the sampling feedback circuit 4 is connected to the output terminal of the rectifier and filter circuit 2, and the output terminal of the sampling feedback circuit 4 is connected to one input terminal of the comparator 3.

[0020] This utility model also includes a constant current overvoltage protection circuit 6. The input terminal of the constant current overvoltage protection circuit 6 is connected to the output terminal of the rectifier filter circuit 2, and the output terminal of the constant current overvoltage protection circuit 6 is connected to the output terminal of the sampling feedback circuit 4, which is used to protect the circuit.

[0021] Example:

[0022] As attached Figure 2 As shown, this example provides a DC high-voltage power supply circuit, which includes a high-voltage converter 1, a rectifier and filter circuit 2, a comparator 3, a sampling feedback circuit 4, and a PWM drive circuit 5. The output terminal of the PWM drive circuit 5 is connected to one input terminal of the comparator 3, the output terminal of the comparator 3 is connected to the high-voltage converter 1, the output terminal of the high-voltage converter 1 is connected to the rectifier and filter circuit 2, the signal input terminal of the sampling feedback circuit 4 is connected to the output terminal of the rectifier and filter circuit 2, and the output terminal of the sampling feedback circuit 4 is connected to one input terminal of the comparator 3.

[0023] The PWM drive circuit includes a MOSFET Q9, which is an N-channel MOSFET. 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 + input of the comparator circuit. The input terminals are connected, the other end of resistor R33 is connected to the drain of MOSFET, one end of resistor R26 is connected to +5V high potential, and the other end is connected in series with TRA+ and resistor R34 in sequence. The other end of resistor R34 is grounded, capacitor C46 is connected in parallel with resistor R34, 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, and the PWM signal is input from one end of resistor R50 to complete the driving of subsequent circuits;

[0024] In this example, 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 between resistor R99 and resistor 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. 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 resistor R107 and resistor R98 to complete the comparison processing of the electrical signal input to the + input terminal.

[0025] The high-voltage converter includes 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 terminals 1 and 4, and the terminals of the second coil are labeled as terminals 2 and 3. The 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 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. 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 transistor Q12, and the second coil generates a self-oscillating signal to the base of transistor Q12.

[0026] The rectifier and filter circuit adopts 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.

[0027] The sampling feedback circuit includes Zener diodes ZD3 and ZD4, diode D5, and an inductor. The anode of Zener diode ZD3 is connected to the anode of diode D5, and the cathode of diode D5 is connected to one end of the inductor, while the other end of the inductor is grounded. The cathode of Zener diode ZD3 is connected to the + input terminal of the comparator via resistor R43A. The anode of Zener diode ZD4 is connected to the cathode of Zener diode ZD3, and the cathode of Zener diode ZD4 is connected to pin 6 on the secondary side of the transformer. This circuit samples the output signal of the high-voltage converter and sends it to the comparator to complete the feedback.

[0028] This example also includes a constant current overvoltage protection circuit 6. The input terminal of the constant current overvoltage protection circuit 6 is connected to the output terminal of the rectifier filter circuit 2, and the output terminal of the constant current overvoltage protection circuit 6 is connected to the output terminal of the sampling feedback circuit 4, which is used to protect the circuit. 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, 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, which is used to provide constant current overvoltage protection for the sampling feedback circuit.

[0029] In operation, this invention sends an electrical signal to the comparator via a PWM drive circuit. The other input terminal of the comparator is set with a comparison voltage value. The electrical signal output by the comparator is output through a high-voltage converter and then passes through a multi-stage rectifier and filter circuit to achieve a stable high-voltage DC signal output. During this process, the electrical signal at the output terminal is fed back to the comparator by a sampling feedback circuit to complete the comparison feedback, thereby improving the reliability and stability of the entire circuit.

[0030] Compared with the prior art, this utility model has significant advantages such as reasonable structure and stable operation.

Claims

1. A DC high-voltage power supply circuit, characterized in that, The 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 DC high-voltage power supply circuit according to claim 1, characterized in that, It also includes a constant current overvoltage protection circuit, the input of which is connected to the output of the rectifier filter circuit, and the output of which is connected to the output of the sampling feedback circuit.

3. The DC high-voltage power supply circuit according to claim 1, characterized in that, The PWM drive circuit includes a MOSFET Q9, which is an N-channel type. The gate (G) of MOSFET Q9 is connected in series with resistor R50, the other end of which is connected to the PWM signal input. 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 which is connected to a 5V high potential. Resistor R52A is connected between resistor R50 and the PWM signal input. Resistors R33 and R43A are connected in series, and the other end of R43A is connected to the + input of the comparator circuit. The input terminals are connected, the other end of resistor R33 is connected to the drain of MOSFET, one end of resistor R26 is connected to +5V high potential, and the other end is connected in series with TRA+ and resistor R34 in sequence. The other end of resistor R34 is grounded, capacitor C46 is connected in parallel with resistor R34, 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, and the PWM signal is input from one end of resistor R50 to drive the subsequent circuit.

4. The DC high-voltage power supply circuit according to claim 1, characterized in that, 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 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. 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.

5. A DC high-voltage power supply circuit according to claim 1, characterized in that, The high-voltage converter includes 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 terminals 1 and 4, and the terminals of the second coil are labeled as terminals 2 and 3. The 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 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. 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.

6. A DC high-voltage power supply circuit according to claim 1, characterized in that, The rectifier and filter circuit adopts 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.

7. A DC high-voltage power supply circuit according to claim 1, characterized in that, The sampling feedback circuit includes Zener diodes ZD3 and ZD4, diode D5, and an inductor. The anode of Zener diode ZD3 is connected to the anode of diode D5, and the cathode of diode D5 is connected to one end of the inductor, while the other end of the inductor is grounded. The cathode of Zener diode ZD3 is connected to the + input terminal of the comparator via resistor R43A. The anode of Zener diode ZD4 is connected to the cathode of Zener diode ZD3, and the cathode of Zener diode ZD4 is connected to pin 6 on the secondary side of the transformer. This circuit samples the output signal of the high-voltage converter and sends it to the comparator to complete the feedback.

8. A DC high-voltage power supply circuit according to claim 2, characterized in that, The constant current overvoltage protection circuit includes a Zener diode ZD5, a diode D81, and a capacitor C4. The cathode of the Zener diode ZD5 is connected to the cathode of the Zener diode ZD4, and the anode of the Zener diode ZD5 is connected to the anode of the diode D81. The cathode of the diode D81 is grounded. One end of the capacitor C4 is grounded, and the other end is connected to the cathode of the Zener diode ZD5. This circuit is used to provide constant current overvoltage protection for the sampling feedback circuit.