High-voltage sampling circuit

Abstract

The utility model discloses a high-voltage sampling circuit, which 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 utility model, the high-voltage alternating-current power supply is adopted to apply at least kilovolt voltage to test the semiconductor, and the failure problem caused by tiny defects of a product can be fed back through detection of a peak signal.

Description

Technical Field

[0001] This utility model relates to the field of product testing technology, specifically a high-voltage sampling circuit. Background Technology

[0002] As the application scenarios of power semiconductor bidirectional thyristors become more widespread, customers have increasingly higher requirements for product reliability. The blocking voltage VDRM and VRRM of the products are generally tested using a static testing method with short-term pulsating DC peaks. Moreover, the blocking voltage VDRM and VRRM testing requires reversal. 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), resulting in low reliability.

[0003] To improve the reliability of early blocking voltage failure caused by minor product defects (such as defects in the voltage slot), it is necessary to develop a blocking voltage sampling circuit based on AC high voltage. Utility Model Content

[0004] The purpose of this invention is to provide a high-voltage sampling circuit to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a high-voltage sampling circuit, comprising a high-voltage AC power supply, a sampling amplification circuit, a peak detection and comparison circuit, a trigger control circuit, an intelligent control module, a protection circuit, an anti-impact circuit, and a reset circuit;

[0006] A high-voltage AC power supply is used to apply voltage to the product under test.

[0007] The sampling amplifier circuit is connected to a high-voltage AC power supply to collect and amplify pulsating voltage signals.

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

[0009] The intelligent control module connects the trigger control circuit, the high-voltage AC power supply, and the reset circuit. It is used to receive the reference voltage comparison trigger signal from the trigger control circuit and to 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 an open circuit, overcurrent, or fault in the product under test, the trigger control circuit outputs a protection control signal to the protection circuit, and the protection circuit performs a power-off operation.

[0011] The surge protection circuit is used to prevent the sampling amplifier circuit and peak detection comparison circuit from being interfered with by the surge of high voltage AC power at the moment of power-on.

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

[0013] Preferably, the peripheral circuit of the high-voltage AC power supply includes a transformer, and the output end of the transformer is provided with two probes for connecting to the product under test.

[0014] Preferably, 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.

[0015] Preferably, the sampling amplifier circuit includes a resistor R3 and operational amplifiers U1 and U2. A resistor R4, a capacitor C1, a Zener diode Dz1, and a resistor R5 are connected in parallel between the resistor R3 and the operational amplifier U1. The operational amplifiers U1 and U2 form a two-stage amplifier circuit. The output terminal of the sampling amplifier circuit is connected to the Zener 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 hold the peak signal. The inverting input of the comparator U5 is connected to a voltage regulator U6. The voltage regulator U6 has an adjustable reference voltage. The peak signal is compared with the reference voltage formed by the voltage regulator U6.

[0017] Preferably, the trigger control circuit includes processors U7 and U8. The positive pulse signal Q is processed and output, then isolated by resistors R19 and R20, transistor Q2, and optocoupler solid-state relay U10 before being sent to the intelligent control module for register processing and output sorting control signals. The negative pulse signal output by processor U7... ō The trigger pulse width is set by resistor R14 and capacitor C5 at the TR+ terminal of the trigger control circuit composed of processor U8. The positive pulse signal Q output by processor U8 is isolated by resistor R17, resistor R18, transistor Q1, and optocoupler solid-state relay U10 and sent to the intelligent control module for register processing and 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 shock protection circuit includes a solid-state relay U13 and a processor U12. One segment 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 amplification circuit.

[0020] Compared with the prior art, the beneficial effects of this utility model are: this utility model uses a high-voltage AC power supply to apply at least kilovolts to test the semiconductor, and by detecting the peak signal, it can accurately reflect the failure problem caused by the minute defects of the product. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall circuit principle of this utility model;

[0022] Figure 2 This is a system block diagram of the present invention;

[0023] Figure 3 This is a schematic diagram of the external connection circuit for a high-voltage AC power supply.

[0024] Figure 4 This is a control block diagram of the present invention. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] like Figure 1-4 As shown, this utility model provides a technical solution including a high-voltage AC power supply, a sampling amplification circuit, a peak detection comparison circuit, a trigger control circuit, an intelligent control module, a protection circuit, an anti-impact circuit, and a reset circuit;

[0027] A high-voltage AC power supply is used to apply voltage to the product under test; a minimum voltage of 1000 volts must be applied to meet the requirements. Figure 1 As shown, the peripheral circuit of the high-voltage AC power supply includes a transformer. Two probes are installed at the transformer's output terminal for connection to the product under test. The protection circuit includes relays K1 and K2 installed at the transformer's input terminal, both of which are connected to a trigger control circuit.

[0028] The sampling amplifier circuit is connected to a high-voltage AC power supply to acquire and amplify pulsating voltage signals; for example... Figure 1 As shown, the sampling amplifier circuit includes resistor R3, operational amplifier U1, and operational amplifier U2. Resistor R4, capacitor C1, Zener diode Dz1, and resistor R5 are connected in parallel between resistor R3 and operational amplifier U1. Operational amplifier U1 and operational amplifier U2 form a two-stage amplifier circuit. Zener diode Dz2 is connected to the output terminal of the sampling amplifier circuit.

[0029] The peak detection and comparison circuit is connected to the sampling and amplification circuit and outputs a reference voltage comparison trigger signal. The peak detection and comparison circuit is connected to the trigger control circuit. The trigger control circuit outputs a protection control signal based on the reference voltage comparison trigger signal output by the peak detection and comparison circuit. The peak detection and comparison circuit includes a processor U3, a comparator U4, and a comparator U5. The processor U3 is used to hold the peak signal. The inverting input of the comparator U5 is connected to a voltage regulator U6. The voltage regulator U6 has an adjustable reference voltage. The peak signal is compared with the reference voltage formed by the voltage regulator U6.

[0030] Reference Figure 1 As shown, the weak pulsating voltage signal sampled by the sampling amplification circuit is filtered by R3 and C1, clamped by DZ1, and then sent to a first-stage amplification composed of the non-inverting + terminal of the TL084(A) op-amp. This is followed by a second-stage amplification composed of the non-inverting + terminal of the TL084(B) op-amp. The two-stage voltage amplification signal, clamped by DZ2, is then sent to a peak detection and hold circuit composed of LF398 and TL084(C). The peak DC voltage signal output by the peak detection and hold circuit is then sent to the comparator U5 (TL084D). The positive terminal is compared with the reference voltage composed of U6 (TL431) to output a trigger signal, which is then 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 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 register processing and output sorting control signal. The negative pulse signal output by U7 (HCF4098) is... ō The trigger pulse width is set by R14 and C5 at the TR+ terminal of the trigger control circuit composed of U8 (HCF4098). The positive pulse signal Q 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 register processing and output protection control signal.

[0031] The intelligent control module connects the trigger control circuit, the high-voltage AC power supply, and the reset circuit. It is used to receive the reference voltage comparison trigger signal from the trigger control circuit and to 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.

[0032] The protection circuit is connected to the trigger control circuit. When the peak detection comparison circuit detects an open circuit, overcurrent, or fault in the product under test, the trigger control circuit outputs a protection control signal to the protection circuit, and the protection circuit performs a power-off operation.

[0033] The surge protection circuit is used to prevent the high voltage AC power surge at the moment of power-on from interfering with the sampling amplification circuit and the peak detection comparison circuit. The surge protection circuit includes a solid-state relay U13 and a processor U12. One part of the processor U12 is connected to the intelligent control module through the solid-state relay U11, and the solid-state relay U13 is connected to the sampling amplification circuit.

[0034] The reset circuit is connected to the intelligent control module and is used to restore the entire circuit to its 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 of which is connected to the intelligent control module.

[0035] The high-voltage sampling circuit described in this embodiment needs to be used in conjunction with a mechanical module when it is applied again. The mechanical module includes an automatic feeding module, a probe testing module, an intelligent sorting module, and an automatic receiving module.

[0036] The following steps are executed under the control of the intelligent control module:

[0037] The product to be tested is input through the automatic feeding module, and the probe testing module is connected to the pins of the product to be tested. Voltage is applied to the probe testing module through a high-voltage AC power supply.

[0038] The pulse signal obtained through sampling and processing by the sampling amplification circuit, peak detection and comparison circuit, and trigger control circuit is sent to the intelligent control module for identification and registration. When the intelligent control module detects qualified or defective products, it outputs a control signal to control the intelligent sorting module. The intelligent sorting module automatically classifies qualified and defective products. The automatic receiving module automatically receives the products into the qualified and defective product tubes according to the classification of the intelligent sorting module. When the intelligent control module detects short circuit, overcurrent, or fault in the tested product, it outputs a control signal to control the protection module, cuts off the AC high voltage source of the high voltage AC power supply module, and alarms. When the fault alarm is cleared, the intelligent control module outputs a control signal to control the reset circuit to reset, and the equipment continues testing.

[0039] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high voltage sampling circuit, characterized by: The high-voltage alternating current power supply, the sampling amplification circuit, the peak value detection comparison circuit, the trigger control circuit, the intelligent control module, the protection circuit, the anti-impact circuit and the reset circuit are included. The high-voltage alternating current power supply is used for applying voltage to the product to be tested. The sampling amplification circuit is connected with the high-voltage alternating current power supply, collects the pulsating voltage signal and amplifies. The peak value detection comparison circuit is connected with the sampling amplification circuit and outputs the reference voltage comparison trigger signal. The intelligent control module is connected with the trigger control circuit, the high-voltage alternating current power supply and the reset circuit, is used for receiving the reference voltage comparison trigger signal of the trigger control circuit and outputting the control to the trigger control circuit, controls the output voltage size of the high-voltage alternating current power supply and the alternating commutation. The protection circuit is connected with the trigger control circuit, and when the peak value detection comparison circuit detects that the product to be tested is disconnected, overflows or fails, the trigger control circuit outputs the protection control signal to the protection circuit, and the protection circuit performs the power-off operation. The anti-impact circuit is used for preventing the high-voltage alternating current power supply from impacting the sampling amplification circuit and the peak value detection comparison circuit. The reset circuit is connected with the intelligent control module and is used for returning the overall circuit to the initial state.

2. The high voltage sampling circuit of claim 1, wherein: The peripheral circuit of the high-voltage alternating current power supply includes a transformer, and two probes are arranged at the output end of the transformer and are used for being connected with the product to be tested.

3. The high voltage sampling circuit of claim 2, wherein: The protection circuit includes a relay K1 and a relay K2 installed at the input end of the transformer, and the relay K1 and the relay K2 are connected with the trigger control circuit.

4. The high voltage sampling circuit of claim 1, wherein: The sampling amplification circuit includes a resistor R3, an operational amplifier U1 and an operational amplifier U2, the resistor R3 is connected with the operational amplifier U1 in parallel with a resistor R4, a capacitor C1, a stabilizing diode Dz1 and a resistor R5, the operational amplifier U1 and the operational amplifier U2 constitute a two-stage amplification circuit, and a stabilizing diode Dz2 is connected to the output end of the sampling amplification circuit.

5. The high voltage sampling circuit of claim 4, wherein: The peak value detection comparison circuit includes a processor U3, a comparator U4 and a comparator U5, the processor U3 is used for peak signal retention, the reverse input end of the comparator U5 is connected with a stabilizer U6, the stabilizer U6 has a reference voltage adjustability, and the peak signal and the reference voltage comparison formed by the stabilizer U6.

6. The high voltage sampling circuit of claim 1, wherein: The trigger control circuit includes processor U7 and processor U8, which processes the positive pulse signal Q output, is sent to the intelligent control module through resistance R19, resistance R20, triode Q2 and optical coupling solid-state relay U10, is isolated and stored to process the output sorting control signal, and the negative pulse signal output by processor U7 ō The TR+ end of the trigger control circuit composed of processor U8 is sent to resistance R14 and capacitor C5 to set the trigger pulse width. The positive pulse signal Q output by processor U8 is sent to the intelligent control module through resistance R17, resistance R18, triode Q1 and optical coupling solid-state relay U10, is isolated and stored to process the output protection control signal.

7. The high voltage sampling circuit of claim 1, wherein: The reset circuit includes one end of a solid-state relay U11 connected with the reset pin of a processor U7 and the other end connected with the intelligent control module.

8. The high-voltage sampling circuit of claim 7, wherein: The anti-impact circuit includes a solid-state relay U13 and a processor U12, one end of the processor U12 is connected with the intelligent control module through the solid-state relay U11, and the solid-state relay U13 is connected with the sampling amplification circuit.

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