High-voltage sampling circuit and control method

Abstract

The invention discloses a high-voltage sampling circuit and a control method. The high-voltage sampling circuit comprises a high-voltage alternating-current power supply, a sampling amplification circuit, a peak detection comparison circuit, a trigger control circuit and an intelligent control module, the high-voltage AC power supply is used for applying voltage to a to-be-tested The sampling amplifying circuit is connected with a high-voltage alternating-current power supply and collects and amplifies pulsating voltage signals. And the peak detection comparison circuit is connected with the sampling amplification circuit and outputs a reference voltage comparison trigger signal, the peak detection comparison circuit is connected with the trigger control circuit, and the trigger control circuit outputs a protection control signal according to the reference voltage comparison trigger signal output by the peak detection comparison circuit. According to the invention, the high-voltage alternating-current power supply is adopted to at least apply kilovolt voltage to test the semiconductor, and the failure problem of the product caused by tiny defects can be fed back by detecting the peak signal.

Description

Technical Field

[0001] The present invention relates to the technical field of product detection, and in particular to a high-voltage sampling circuit and a control method. Background Art

[0002] As the application scenarios of power semiconductor bidirectional thyristors become more and more extensive, customers have higher and higher requirements for product reliability. The product blocking voltage VDRM and VRRM detection generally adopts a short-time static detection method of pulsating DC peak, and the blocking voltage VDRM and VRRM detection requires reversing. This type of test method cannot effectively detect some early blocking voltage failures caused by minor product defects (such as defects in the voltage slot), and has low reliability.

[0003] In order to improve the reliability of early blocking voltage failure caused by subtle product defects (such as defects in the voltage slot), it is necessary to develop a blocking voltage sampling circuit based on AC high voltage. Summary of the invention

[0004] The object of the present invention is to provide a high voltage sampling circuit to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: a high-voltage sampling circuit, comprising a high-voltage AC power supply, a sampling amplifier circuit, a peak detection comparison circuit, a trigger control circuit, an intelligent control module, a protection circuit, an anti-shock circuit and a reset circuit;

[0006] A high voltage AC power source is used to apply voltage to the product under test;

[0007] The sampling and amplifying circuit is connected to a high-voltage AC power supply to collect and amplify the pulsating voltage signal;

[0008] The peak detection comparison circuit is connected to the sampling and amplifying circuit and outputs a reference voltage comparison trigger signal. The peak detection comparison circuit and the trigger control circuit output a protection control signal according to the reference voltage comparison trigger signal output by the peak detection comparison circuit.

[0009] The intelligent control module is connected to the trigger control circuit, the high-voltage AC power supply and the reset circuit, and is used to receive the reference voltage comparison trigger signal of the trigger control circuit and output control to the trigger control circuit. The intelligent control module controls the output voltage of the high-voltage AC power supply and the AC commutation;

[0010] The protection circuit is connected to the trigger control circuit. When the peak detection comparison circuit detects that the product to be tested is open circuit, overcurrent or faulty, the trigger control circuit outputs a protection control signal to the protection circuit, and the protection circuit performs a power-off operation.

[0011] The anti-shock circuit is used to prevent the high-voltage AC power supply from interfering with the sampling amplifier circuit and the peak detection comparison circuit during the power-on moment;

[0012] The reset circuit is connected to the intelligent control module and is used to restore the entire circuit to an initial state.

[0013] Preferably, the peripheral circuit of the high-voltage AC power supply includes a transformer, and two probes are provided at the output end of the transformer for connecting to the product to be tested.

[0014] Preferably, the protection circuit comprises a relay K1 and a relay K2 installed at the input end of the transformer, and the relay K1 and the relay K2 are both connected to the trigger control circuit.

[0015] Preferably, the sampling and amplifying circuit includes a resistor R3 and an operational amplifier U1 and an operational amplifier U2. A resistor R4, a capacitor C1, a voltage-stabilizing diode Dz1 and a resistor R5 are connected in parallel between the resistor R3 and the operational amplifier U1. The operational amplifier U1 and the operational amplifier U2 form a two-stage amplifying circuit. The output end of the sampling and amplifying circuit is connected to a voltage-stabilizing diode Dz2.

[0016] Preferably, the peak detection comparison circuit includes a processor U3, a comparator U4 and a comparator U5. The processor U3 is used to maintain the peak signal. The reverse input end of the comparator U5 is connected to a regulator U6. The regulator U6 has an adjustable reference voltage. The peak signal is compared with the reference voltage formed by the regulator U6.

[0017] Preferably, the trigger control circuit includes a processor U7 and a processor U8, which process the output positive pulse signal Q, which is isolated by a resistor R19, a resistor R20, a transistor Q2, and an optocoupler solid-state relay U10 and sent to the intelligent control module for storage and processing of the output sorting control signal, and the negative pulse signal output by the processor U7 ō The signal is sent to the TR+ terminal of the trigger control circuit composed of the processor U8. The resistor R14 and the capacitor C5 set the trigger pulse width. The positive pulse signal Q processed and output by the processor U8 is isolated by the resistor R17, the resistor R18, the transistor Q1 and the optocoupler solid-state relay U10 and sent to the intelligent control module for storage and processing of the output protection control signal.

[0018] Preferably, the reset circuit includes a solid-state relay U11, one end of which is connected to the reset pin of the processor U7, and the other end of which is connected to the intelligent control module.

[0019] Preferably, the anti-shock circuit includes a solid-state relay U13 and a processor U12, a section of the processor U12 is connected to the intelligent control module via the solid-state relay U11, and the solid-state relay U13 is connected to the sampling and amplifying circuit.

[0020] A control method, which uses the above-mentioned high-voltage sampling circuit, and also includes a mechanical module, the mechanical module includes an automatic feeding module, a probe testing module, an intelligent sorting module and an automatic receiving module;

[0021] The method also includes executing the following steps under the control of the intelligent control module:

[0022] The product to be tested is input through the automatic feeding module, the probe test module is connected to the pin of the product to be tested, and voltage is applied to the probe test module through a high-voltage AC power supply;

[0023] The pulse signal output is obtained through sampling and processing by the sampling and amplification circuit, the peak detection and comparison circuit, and the trigger control circuit and is sent to the intelligent control module for identification and storage processing. When the intelligent control module detects qualified products or defective products, the intelligent control module outputs a control signal to control the intelligent sorting module. The intelligent sorting module automatically classifies qualified products and defective products. The automatic material receiving module automatically receives materials into qualified material tubes and defective material tubes according to the classification of the intelligent sorting module. When the intelligent control module detects that the tested product is short-circuited, over-current, or faulty, the intelligent control module outputs a control signal to control the protection module, cuts off the high-voltage AC power supply module's AC source and alarms. When the fault alarm is released, the intelligent control module outputs a control signal to control the reset circuit to reset, and the equipment continues testing.

[0024] Compared with the prior art, the present invention has the following beneficial effects: the present invention uses a high-voltage AC power supply to apply at least a kilovolt voltage to test semiconductors, and by detecting the peak signal, it is able to provide feedback on failure problems of precise products caused by subtle defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall circuit principle of the present invention;

[0026] Figure 2 is a system block diagram of the present invention;

[0027] Figure 3 It is a schematic diagram of the peripheral connection circuit of the high voltage AC power supply;

[0028] Figure 4 This is a control block diagram of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] like Figure 1-4 As shown, the present invention provides a technical solution: including a high-voltage AC power supply, a sampling and amplifying circuit, a peak detection and comparison circuit, a trigger control circuit, an intelligent control module, a protection circuit, an anti-shock circuit and a reset circuit;

[0031] The high voltage AC power supply is used to apply voltage to the product to be tested, and a voltage of at least 1000 volts is applied to meet the requirements; Figure 1 As shown, the peripheral circuit of the high-voltage AC power supply includes a transformer, and two probes are set at the output end of the transformer for connecting to the product to be tested. The protection circuit includes relays K1 and K2 installed at the input end of the transformer, and both relays K1 and K2 are connected to the trigger control circuit.

[0032] The sampling and amplifying circuit is connected to a high-voltage AC power supply to collect and amplify the pulsating voltage signal; Figure 1 As shown, the sampling and amplifying circuit includes a resistor R3 and operational amplifiers U1 and U2. A resistor R4, a capacitor C1, a voltage-stabilizing diode Dz1 and a resistor R5 are connected in parallel between the resistor R3 and the operational amplifier U1. The operational amplifier U1 and the operational amplifier U2 form a two-stage amplifying circuit. The output end of the sampling and amplifying circuit is connected to a voltage-stabilizing diode Dz2.

[0033] The peak detection comparison circuit is connected to the sampling and amplifying circuit and outputs a reference voltage comparison trigger signal. The peak detection comparison circuit and the trigger control circuit output a protection control signal according to the reference voltage comparison trigger signal output by the peak detection comparison circuit. The peak detection comparison circuit includes a processor U3, a comparator U4 and a comparator U5. The processor U3 is used to maintain the peak signal. The reverse input end of the comparator U5 is connected to a regulator U6. The regulator U6 has adjustable reference voltage. The peak signal is compared with the reference voltage composed of the regulator U6.

[0034] Reference Figure 1As shown in the figure, the weak pulsating voltage signal sampled by the sampling and amplification circuit is filtered by R3 and C1, clamped by DZ1, and sent to the first-stage amplification composed of the in-phase + terminal of the TL084 (A) operational amplifier, and then sent to the second-stage amplification composed of the in-phase + terminal of the TL084 (B) operational amplifier. The two-stage voltage amplification signal clamped by DZ2 is sent to the peak detection and holding circuit composed of LF398 and TL084 (C). The peak DC voltage signal output by the peak detection and holding circuit is sent to the in-phase + terminal of the U5 (TL084D) comparator. The phase + terminal is compared with the reference voltage composed of U6 (TL431) to output the trigger signal, which is sent to the TR+ terminal of the trigger control circuit composed of U7 (HCF4098). R12 and C4 set the trigger pulse width. The positive pulse signal Q processed and output by U7 (HCF4098) is isolated by R19, R20, Q2, and U10 (AQY212) optocoupler solid-state relay and sent to the intelligent control module for storage, processing, and output sorting control signal. The negative pulse signal output by U7 (HCF4098) ō It is sent to the TR+ end of the trigger control circuit composed of U8 (HCF4098), R14 and C5 set the trigger pulse width, and the positive pulse signal Q processed and output by U8 (HCF4098) is isolated by R17, R18, Q1, and U10 (AQY212) optocoupler solid-state relay and sent to the intelligent control module for storage and processing of the output protection control signal.

[0035] The intelligent control module is connected to the trigger control circuit, the high-voltage AC power supply and the reset circuit, and is used to receive the reference voltage comparison trigger signal of the trigger control circuit and output control to the trigger control circuit. The intelligent control module controls the output voltage of the high-voltage AC power supply and the AC commutation;

[0036] The protection circuit is connected to the trigger control circuit. When the peak detection comparison circuit detects that the product to be tested is open circuit, overcurrent or faulty, the trigger control circuit outputs a protection control signal to the protection circuit, and the protection circuit performs a power-off operation.

[0037] The anti-shock circuit is used to prevent the high-voltage AC power supply shock at the moment of power-on from interfering with the sampling and amplifying circuit and the peak detection and comparison circuit; the anti-shock circuit includes a solid-state relay U13 and a processor U12, one section of the processor U12 is connected to the intelligent control module via the solid-state relay U11, and the solid-state relay U13 is connected to the sampling and amplifying circuit.

[0038] The reset circuit is connected to the intelligent control module and is used to restore the entire circuit to the initial state. The reset circuit includes a solid-state relay U11, one end of which is connected to the reset pin of the processor U7, and the other end is connected to the intelligent control module.

[0039] The high-voltage sampling circuit described in this embodiment needs to be used in conjunction with a mechanical module, which includes an automatic feeding module, a probe testing module, an intelligent sorting module, and an automatic receiving module;

[0040] Perform the following steps under the control of the intelligent control module:

[0041] The product to be tested is input through the automatic feeding module, the probe test module is connected to the pin of the product to be tested, and voltage is applied to the probe test module through a high-voltage AC power supply;

[0042] The pulse signal output is obtained through sampling and processing by the sampling and amplification circuit, the peak detection and comparison circuit, and the trigger control circuit and is sent to the intelligent control module for identification and storage processing. When the intelligent control module detects qualified products or defective products, the intelligent control module outputs a control signal to control the intelligent sorting module. The intelligent sorting module automatically classifies qualified products and defective products. The automatic material receiving module automatically receives materials into qualified material tubes and defective material tubes according to the classification of the intelligent sorting module. When the intelligent control module detects that the tested product is short-circuited, over-current, or faulty, the intelligent control module outputs a control signal to control the protection module, cuts off the high-voltage AC power supply module's AC source and alarms. When the fault alarm is released, the intelligent control module outputs a control signal to control the reset circuit to reset, and the equipment continues testing.

[0043] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high voltage sampling circuit, characterized in that: It includes a high-voltage AC power supply, a sampling amplifier circuit, a peak detection comparison circuit, a trigger control circuit, an intelligent control module, a protection circuit, an anti-shock circuit and a reset circuit; A high voltage AC power source is used to apply voltage to the product under test; The sampling and amplifying circuit is connected to a high-voltage AC power supply to collect and amplify the pulsating voltage signal; The peak detection comparison circuit is connected to the sampling and amplifying circuit and outputs a reference voltage comparison trigger signal. The peak detection comparison circuit and the trigger control circuit output a protection control signal according to the reference voltage comparison trigger signal output by the peak detection comparison circuit. The intelligent control module is connected to the trigger control circuit, the high-voltage AC power supply and the reset circuit, and is used to receive the reference voltage comparison trigger signal of the trigger control circuit and output control to the trigger control circuit. The intelligent control module controls the output voltage of the high-voltage AC power supply and the AC commutation; The protection circuit is connected to the trigger control circuit. When the peak detection comparison circuit detects that the product to be tested is open circuit, overcurrent or faulty, the trigger control circuit outputs a protection control signal to the protection circuit, and the protection circuit performs a power-off operation. The anti-shock circuit is used to prevent the high-voltage AC power supply from interfering with the sampling amplifier circuit and the peak detection comparison circuit during the power-on moment; The reset circuit is connected to the intelligent control module and is used to restore the entire circuit to an initial state.

2. A high voltage sampling circuit according to claim 1, characterized in that: The peripheral circuit of the high-voltage AC power supply includes a transformer. Two probes are arranged at the output end of the transformer for connecting with the product to be tested.

3. A high voltage sampling circuit according to claim 2, characterized in that: The protection circuit comprises a relay K1 and a relay K2 installed at the input end of the transformer, and both the relay K1 and the relay K2 are connected to the trigger control circuit.

4. A high voltage sampling circuit according to claim 1, characterized in that: The sampling and amplifying circuit includes a resistor R3 and operational amplifiers U1 and U2. A resistor R4, a capacitor C1, a voltage-stabilizing diode Dz1 and a resistor R5 are connected in parallel between the resistor R3 and the operational amplifier U1. The operational amplifier U1 and the operational amplifier U2 form a two-stage amplifying circuit. The output end of the sampling and amplifying circuit is connected to a voltage-stabilizing diode Dz2.

5. A high voltage sampling circuit according to claim 4, characterized in that: The peak detection comparison circuit includes a processor U3, a comparator U4 and a comparator U5. The processor U3 is used to maintain the peak signal. The reverse input end of the comparator U5 is connected to a regulator U6. The regulator U6 has an adjustable reference voltage. The peak signal is compared with the reference voltage formed by the regulator U6.

6. A high voltage sampling circuit according to claim 1, characterized in that: The trigger control circuit includes processor U7 and processor U8, which process the output positive pulse signal Q, which is isolated by resistor R19, resistor R20, transistor Q2, and optocoupler solid-state relay U10 and sent to the intelligent control module for storage and processing of the output sorting control signal. The negative pulse signal output by processor U7 ō The signal is sent to the TR+ terminal of the trigger control circuit composed of the processor U8. The resistor R14 and the capacitor C5 set the trigger pulse width. The positive pulse signal Q processed and output by the processor U8 is isolated by the resistor R17, the resistor R18, the transistor Q1 and the optocoupler solid-state relay U10 and sent to the intelligent control module for storage and processing of the output protection control signal.

7. The high voltage sampling circuit according to claim 1, characterized in that: The reset circuit includes a solid-state relay U11, one end of which is connected to the reset pin of the processor U7, and the other end of which is connected to the intelligent control module.

8. A high voltage sampling circuit according to claim 7, characterized in that: The anti-shock circuit includes a solid-state relay U13 and a processor U12. One section of the processor U12 is connected to the intelligent control module via the solid-state relay U11, and the solid-state relay U13 is connected to the sampling and amplifying circuit.

9. A control method, characterized in that: A high-voltage sampling circuit according to any one of claims 1 to 8 is applied, and further comprises a mechanical module, the mechanical module comprising an automatic feeding module, a probe testing module, an intelligent sorting module and an automatic receiving module; The method also includes executing the following steps under the control of the intelligent control module: The product to be tested is input through the automatic feeding module, the probe test module is connected to the pin of the product to be tested, and voltage is applied to the probe test module through a high-voltage AC power supply; The pulse signal output is obtained through sampling and processing by the sampling and amplification circuit, the peak detection and comparison circuit, and the trigger control circuit and is sent to the intelligent control module for identification and storage processing. When the intelligent control module detects qualified products or defective products, the intelligent control module outputs a control signal to control the intelligent sorting module. The intelligent sorting module automatically classifies qualified products and defective products. The automatic material receiving module automatically receives materials into qualified material tubes and defective material tubes according to the classification of the intelligent sorting module. When the intelligent control module detects that the tested product is short-circuited, over-current, or faulty, the intelligent control module outputs a control signal to control the protection module, cuts off the high-voltage AC power supply module's AC source and alarms. When the fault alarm is released, the intelligent control module outputs a control signal to control the reset circuit to reset, and the equipment continues testing.

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