WIDE-RANGE POSITIVE-NEGATIVE ADJUSTABLE HIGH-VOLTAGE DC POWER SUPPLY AND THE CONTROL METHOD THEREOF

• US 20180048231A1
• Filed: 08/11/2017
• Published: 02/15/2018
• Est. Priority Date: 08/11/2016
• Status: Active Grant

• Current Assignee: Huizhou Sanhua Industrial Company Limited
• Original Assignee: Huizhou Sanhua Industrial Company Limited
• Inventors: Li, Jianming, Liu, Zheng, Sun, Jianping, Zhang, Chengshun
• Granted Patent: US 10,312,812 B2
• Time in Patent Office: Days
• CPC Class Codes: B41J 29/393 Devices for controlling or analysing the entire machine ; Controlling or analysing mechanical parameters involving printing of test patterns
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel

Abstract

A wide-range positive-negative adjustable high-voltage DC power supply includes the following components: a high-voltage generator, a negative high-voltage terminal, and a positive high-voltage terminal; a first driving circuit, a first voltage regulating unit, a current detection and amplification circuit, a second driving circuit and a second voltage regulating unit that are connected in turn; and an adjustable high-voltage output terminal; as well as an instruction input terminal, an instruction voltage circuit and an error amplifier that are connected in turn, and a voltage feedback circuit.

Claims

1. A wide-range positive-negative adjustable high-voltage DC power supply, comprising the following components:

a high-voltage generator, a negative high-voltage terminal, a positive high-voltage terminal, a first driving circuit, a first voltage regulating unit, a current detection and amplification circuit, a second driving circuit, a second voltage regulating unit and an adjustable high-voltage output terminal;

as well as an instruction input terminal, an instruction voltage circuit, an error amplifier and a voltage feedback circuit;

wherein the high-voltage generator is respectively connected to the positive high-voltage terminal and the negative high-voltage terminal, the positive high-voltage terminal is connected to the input terminal of the first voltage regulating unit, the negative high-voltage terminal is connected to the input terminal of the second voltage regulating unit, the output terminal of the first voltage regulating unit is connected to the output terminal of the second voltage regulating unit and then to the adjustable high-voltage output terminal, the output terminal of the first driving circuit is connected to the driving terminal of the first voltage regulating unit, the current detection terminal of the first voltage regulating unit is connected to the detection input terminal of the current detection and amplification circuit, the output terminal of the current detection and amplification circuit is connected to the input terminal of the second driving circuit, and the output terminal of the second driving circuit is connected to the driving terminal of the second voltage regulating unit;

the instruction input terminal, the instruction voltage circuit and the error amplifier are connected in turn, wherein the output terminal of the error amplifier is connected to the input terminal of the first driving circuit, the input terminal of the voltage feedback circuit is respectively connected to the output terminal of the first voltage regulating unit and the output terminal of the second voltage regulating unit, and the output terminal of the voltage feedback circuit is connected to the error amplifier.

2. The wide-range positive-negative adjustable high-voltage DC power supply according to claim 1, wherein the first voltage regulating unit comprises m PNP transistors Q1-1, Q1-2, . . . Q1-m, m+1 resistors R1-0, R1-1, R1-2, . . . R1-m, and one Zener diode D1-1;

it also comprises an input terminal, an output terminal, a current detection terminal and a driving terminal;

wherein m≧

1 and m is an integer;

collectors and emitters of the m PNP transistors are connected to each other in series in turn, wherein the emitter of the first transistor Q1-1 is connected to the anode of the Zener diode D1-1, the cathode of the Zener diode D1-1 is connected to one electrode of the current detection terminal of the first voltage regulating unit, the other electrode of the current detection terminal is connected to the input terminal of the first voltage regulating unit, one terminal of the resistor R1-0 is connected to one electrode of the driving terminal of the first voltage regulating unit, the other electrode of the driving terminal is connected to the input terminal of the first voltage regulating unit, the other terminal of the resistor R1-0 is connected to the base of the PNP transistor Q1-1, the two terminals of the resistor R1-m are respectively connected to the base and collector of the transistor Q1-m, the collector of the transistor Q1-m is also connected to the output terminal of the first voltage regulating unit, and the remaining m−

1 resistors are respectively connected across the bases of the m transistors connected in series in turn.

3. The wide-range positive-negative adjustable high-voltage DC power supply according to claim 1, wherein the second voltage regulating unit comprises n NPN transistors Q2-1, Q2-2, . . . Q2-n, n+1 resistors R2-0, R2-1, R2-2, . . . R2-n, and one Zener diode D2-1;

it also comprises an input terminal, an output terminal and a driving terminal;

wherein n≧

1 and n is an integer;

collectors and emitters of the n NPN transistors are connected to each other in series in turn, wherein the emitter of the first transistor Q2-1 is connected to the cathode of the Zener diode D2-1, the anode of the Zener diode D2-1 is connected to the input terminal of the second voltage regulating unit, one terminal of the resistor R2-0 is connected to one electrode of the driving terminal of the second voltage regulating unit, the other electrode of the driving terminal is connected to the input terminal of the second voltage regulating unit, the other terminal of the resistor R2-0 is connected to the base of the NPN transistor Q2-1, the two terminals of the resistor R2-n are respectively connected to the base and collector of the transistor Q2-n, the collector of the transistor Q2-n is also connected to the output terminal of the second voltage regulating unit, and the remaining n−

1 resistors are respectively connected across the bases of the n transistors connected in series in turn.

4. The wide-range positive-negative adjustable high-voltage DC power supply according to claim 1, wherein the first driving circuit comprises one transistor Q3-1 and five resistors R3-1, R3-2, . . . R3-5, as well as an input terminal and an output terminal;

the emitter of the transistor Q3-1 is connected to one terminal of the resistor R3-1, the other terminal of the resistor R3-1 is connected to one electrode of the input terminal of the first driving circuit, the base of the transistor Q3-1 is respectively connected to one terminal of the resistors R3-2 and R3-3, the other terminal of the resistors R3-2 and R3-3 is respectively connected to the two electrodes of the input terminal of the first driving circuit, the collector of the transistor Q3-1 is connected to one terminal of the resistor R3-4, the other terminal of the resistor R3-4 is connected to one electrode of the output terminal of the first driving circuit, and the two terminals of the resistor R3-5 are respectively connected to the two electrodes of the output terminal of the first driving circuit.

5. The wide-range positive-negative adjustable high-voltage DC power supply according to claim 1, wherein the second driving circuit comprises an optocoupler U4-1 and a resistor R4-1, as well as an input terminal and an output terminal;

the anode of a light-emitting diode in the optocoupler U4-1 is connected to one terminal of the resistor R4-1, the other terminal of the resistor R4-1 is connected to one electrode of the input terminal of the second driving circuit, the cathode of the light emitting diode is connected to the other electrode of the input terminal of the second driving circuit, and the two terminals of a photosensitive tube in the optocoupler U4-1 are respectively connected to the two electrodes of the output terminal of the second driving circuit.

6. The wide-range positive-negative adjustable high-voltage DC power supply according to claim 1, wherein the current detection and amplification circuit comprises a transistor Q5-1 and a resistor R5-1, as well as a detection input terminal and an output terminal;

wherein the emitter and the base of the transistor Q5-1 are respectively connected to the two electrodes of the detection input terminal of the current detection and amplification circuit, the collector of the transistor Q5-1 is connected to one electrode of the output terminal of the current detection and amplification circuit, the other electrode of the output terminal is connected to a reference voltage point, and the two electrodes of the resistor R5-1 are respectively connected to the base and the emitter of the transistor Q5-1.

7. The wide-range positive-negative adjustable high-voltage DC power supply according to claim 1, wherein the current detection and amplification circuit comprises an optocoupler U5-1 and an amplifier A5-1, as well as a detection input terminal and an output terminal;

wherein the two terminals of a light-emitting diode in the optocoupler U5-1 are respectively connected to the two electrodes of the detection input terminal of the current detection and amplification circuit, the two terminals of a photosensitive tube in the optocoupler U5-1 are respectively connected to the two input terminals of the amplifier A5-1, and the two output terminals of the amplifier A5-1 are respectively connected to the two electrodes of the output terminal of the current detection and amplification circuit.

8. The wide-range positive-negative adjustable high-voltage DC power supply according to claim 7, wherein a proportional amplifier composed of an operational amplifier LM324 is used in the amplifier A5-1.

9. A method of controlling the wide-range positive-negative adjustable high-voltage DC power supply according to claim 1, comprising the following steps:

step 1;

producing positive and negative high voltages through the high-voltage generator, wherein the positive and negative high voltages are respectively sent to the positive high-voltage terminal and the negative high-voltage terminal, wherein the voltage value of the positive high-voltage terminal is greater than the upper limit value of the output voltage regulation range of the wide-range positive-negative adjustable high-voltage DC power supply, and the voltage value of the negative high-voltage terminal is less than the lower limit value thereof;

step 2;

inputting a PWM voltage regulation instruction by the instruction input terminal;

step 3;

converting the PWM voltage regulation instruction into an instruction voltage by the instruction voltage circuit;

step 4;

comparing and amplifying the instruction voltage with the feedback voltage from the voltage feedback circuit the error amplifier, and sending the operation results to the first driving circuit, and driving the first voltage regulating unit to adjust the voltage through the first driving circuit;

step 5;

detecting the emitter current of the PNP transistor Q1-1 in the first voltage regulating unit, and amplifying the detection results through the current detection and amplification circuit before sending them into the second driving circuit, and driving the second voltage regulating unit to participate in the voltage regulation through the second driving circuit;

wherein the amplification factor of the current detection and amplification circuit should satisfy the following conditions;

if the emitter current of the PNP transistor Q1-1 in the first voltage regulating unit is recorded as I₁, which has a maximum value of I_1M, then;

when I₁≧

0.1I_1M, the NPN transistor Q2-1 in the second voltage regulating unit is driven to enter an off state;

when 0<

I₁<

0.1I_1M, the NPN transistor Q2-1 in the second voltage regulating unit is driven to enter an amplification region to participate in the voltage regulation; and

when I₁=0, the emitter current of the NPN transistor Q2-1 in the second voltage regulating unit is driven to reach its maximum value;

step 6;

sampling and feeding back to the error amplifier the output voltage of the wide-range positive-negative adjustable high-voltage DC power supply by the voltage feedback circuit, comparing the output voltage with the instruction voltage, and controlling the output voltage to meet the instruction requirements after operation by the error amplifier.