Contact resistance tester

Abstract

The utility model belongs to the technical field of equipment, and particularly relates to a contact resistance tester, which comprises a sine wave inverter generator module, a driving module, a comparator module and a push-free circuit module, the sine wave inverter generator module is connected with the push-free circuit module, the push-free circuit module is connected with the driving module, and an SPWM (sinusoidal pulse width modulation) waveform passes through the push-free circuit module through an output port of the sine wave inverter generator module and is input into the driving module; the sine wave inverter generator module is connected with the comparator module, and the comparator module is used for collecting the value of voltage flowing through the sine wave inverter generator module and judging whether the contact resistance tester is over-current or not. The utility model belongs to the field of resistance testing. The contact resistance tester provided by the utility model is high in safety.

Description

TECHNICAL FIELD

[0001] The utility model belongs to resistance test technical field especially, it is a kind of contact resistance tester. BACKGROUND

[0002] The main role of contact resistance tester is to measure the contact resistance value of electrical connection point (such as terminal, switch contact, cable connection etc.). Contact resistance refers to the resistance caused by surface roughness, oxide layer, pollution and other factors on the contact surface of two conductors, and contact resistance tester has important influence on the safety and efficiency of electrical system. The existing contact resistance tester has the problem of weak safety. Therefore, it is urgent to provide a contact resistance tester with high safety. SUMMARY

[0003] In view of the technical problems in the background art, the utility model provides a contact resistance tester, which has simple structure and high safety.

[0004] To achieve the above object, the utility model provides the technical scheme as follows:

[0005] A contact resistance tester, the device includes: sine wave inverter generator module, drive module, comparator module and push circuit module;

[0006] The sine wave inverter generator module is connected with the push circuit module, the push circuit module is connected with the drive module, and SPWM pulse width modulation waveform is input into the drive module through the output port of the sine wave inverter generator module and the push circuit module;

[0007] The sine wave inverter generator module is connected with the comparator module, and the comparator module is used to collect the voltage value flowing through the sine wave inverter generator module and determine whether the contact resistance tester is overcurrent.

[0008] Further, it includes that the sine wave inverter generator module includes EG8010 chip;The drive module includes two I R2113S chips;The comparator module includes LM393 chip.

[0009] Further, the 30th pin of the EG8010 chip is connected with one end of the resistor 32 and the emitter of the transistor Q2; the 29th pin of the EG8010 chip is connected with one end of the resistor 30 and the emitter of the transistor Q3; the 28th pin of the EG8010 chip is connected with one end of the resistor 36 and the emitter of the transistor Q4; the 27th pin of the EG8010 chip is connected with one end of the resistor 34 and the emitter of the transistor Q5; the base of the transistor Q2 is connected with the other end of the resistor 30, and the collector of the transistor Q2 is used as an output terminal; the base of the transistor Q3 is connected with the other end of the resistor 32, and the collector of the transistor Q3 is used as an output terminal; the base of the transistor Q4 is connected with the other end of the resistor 34, and the collector of the transistor Q4 is used as an output terminal; the base of the transistor Q5 is connected with the other end of the resistor 36, and the collector of the transistor Q5 is used as an output terminal.

[0010] Further, the 32th pin, the 18th pin, the 19th pin, the 20th pin, the 21th pin and the 16th pin of the EG8010 chip are grounded; the 17th pin of the EG8010 chip is connected with a 5v power supply; the 1st pin of the EG8010 chip is connected with a 5v power supply; the 26th pin of the EG8010 chip is connected with one end of the capacitor C9, and the other end of the capacitor C9 is grounded; the 26th pin of the EG8010 chip is connected with one end of the capacitor C10, and the other end of the capacitor C10 is grounded; the capacitor C10 and the capacitor C9 are connected with a 5v power supply; the 8th pin of the EG8010 chip is connected with the negative electrode of the diode D1, the positive electrode of the diode D1 is connected with one end of the resistor 1, and the other end of the resistor 1 is connected with a 5v power supply; the 9th pin of the EG8010 chip is connected with one end of the capacitor C1, the 12th pin of the EG8010 chip is connected with the capacitor C9, the relay Y1 is connected with the other end of the capacitor C9 and the other end of the capacitor C1, the 10th pin of the EG8010 chip is connected with one end of the relay Y1, the 11th pin of the EG8010 chip is connected with the other end of the relay Y1, the 12th pin of the EG8010 chip is grounded, the 13th pin of the EG8010 chip is connected with one end of the capacitor C15, the other end of the capacitor C15 is grounded, the 13th pin of the EG8010 chip is also connected with the resistor 2, the other end of the resistor 2 is connected with the P1 port; the 15th pin of the EG8010 chip is connected with one end of the capacitor C16, the other end of the capacitor C16 is grounded, the 15th pin of the EG8010 chip is connected with one end of the resistor 3, the other end of the resistor 3 is connected with the P1 port, the other end of the resistor 3 is also connected with one end of the resistor 8, the other end of the resistor 8 is grounded; the 14th pin of the EG8010 chip is connected with one end of the capacitor C24, the other end of the capacitor C24 is grounded, the 14th pin of the EG8010 chip is also connected with one end of the resistor 38, the other end of the resistor 38 is connected with the capacitor C21, the other end of the resistor 38 is connected with one end of the resistor 7, the other end of the resistor 7 is connected with the P1 port, the other end of the capacitor C21 is grounded, and the 7th pin of the EG8010 chip is connected with the P1 port.

[0011] Further, the first pin of the LM393 chip is connected with one end of the resistor 4, the other end of the resistor 4 is grounded, the first pin of the LM393 chip is also connected with the 13th pin of the first IR2113S chip, the first pin of the LM393 chip is also connected with the 13th pin of the second IR2113S chip, the first pin of the LM393 chip is also connected with one end of the resistor 26, the other end of the resistor 26 is connected with the 3rd pin and the 6th pin of the LM393 chip at the same time; the 2nd pin of the LM393 chip is connected with the 5th pin of the LM393 chip, the 2nd pin of the LM393 chip is also connected with one end of the resistor 5, the 2nd pin of the LM393 chip is also connected with one end of the resistor 6, the other end of the resistor 6 is grounded, and the capacitor C20 is connected outside, the other end of the resistor 5 is connected with one end of the capacitor C18 and the capacitor C17 at the same time, the other end of the capacitor C18 and the capacitor C17 is grounded; the 3rd pin of the LM393 chip is connected with the 6th pin of the LM393 chip; the 4th pin of the LM393 chip is grounded; the 6th pin of the LM393 chip is connected with one end of the resistor 38, one end of the capacitor C21 and one end of the resistor 7 at the same time, the other end of the resistor 7 is connected with the P1 port; the 8th pin of the LM393 chip is connected with one end of the resistor 5, the capacitor C18 and the capacitor C17 at the same time, one end of the capacitor C18 and the capacitor C17 is connected with the 5V power supply outside.

[0012] Further, the first pin of the LM393 chip is connected with one end of the resistor 4, the other end of the resistor 4 is grounded, the first pin of the LM393 chip is also connected with the 13th pin of the first IR2113S chip, the first pin of the LM393 chip is also connected with the 13th pin of the second IR2113S chip, the first pin of the LM393 chip is also connected with one end of the resistor 26, the other end of the resistor 26 is connected with the 3rd pin and the 6th pin of the LM393 chip at the same time; the 2nd pin of the LM393 chip is connected with the 5th pin of the LM393 chip, the 2nd pin of the LM393 chip is also connected with one end of the resistor 5, the 2nd pin of the LM393 chip is also connected with one end of the resistor 6, the other end of the resistor 6 is grounded, and the capacitor C20 is connected outside, the other end of the resistor 5 is connected with one end of the capacitor C18 and the capacitor C17 at the same time, the other end of the capacitor C18 and the capacitor C17 is grounded; the 3rd pin of the LM393 chip is connected with the 6th pin of the LM393 chip; the 4th pin of the LM393 chip is grounded; the 6th pin of the LM393 chip is connected with one end of the resistor 38, one end of the capacitor C21 and one end of the resistor 7 at the same time, the other end of the resistor 7 is connected with the P1 port; the 8th pin of the LM393 chip is connected with one end of the resistor 5, the capacitor C18 and the capacitor C17 at the same time, one end of the capacitor C18 and the capacitor C17 is connected with the 5V power supply outside.

[0013] Further, it further comprises: the 1st pin of the second IR2113S chip is connected with the P1 port; the 2nd pin of the second IR2113S chip and the 15th pin of the second IR2113S chip are grounded; the 3rd pin of the second IR2113S chip is connected with one end of the capacitor C11, one end of the capacitor C12 and the anode of the diode D3 at the same time, the other end of the capacitor C11 and the other end of the capacitor C12 are grounded, one end of the capacitor C11 and one end of the capacitor C12 are further connected with a 12V power supply, the anode of the diode D3 is connected with one end of the capacitor C8 and the 7th pin of the second IR2113S chip at the same time, the other end of the capacitor C8 is connected with the P1 port; the 8th pin of the second IR2113S chip is connected with the P1 port; the 11th pin of the second IR2113S chip is connected with one end of the capacitor C13 and one end of the capacitor C14 at the same time, the other end of the capacitor C13 and the other end of the capacitor C14 are connected and grounded at the same time, one end of the capacitor C13 and one end of the capacitor C14 are connected with a 5V power supply; the 12th pin of the second IR2113S chip is connected with the pole electrode of the transistor Q5 and one end of the resistor 37 at the same time, one end of the resistor 37 is also connected with the pole electrode of the transistor Q5, and the other end of the resistor 37 is grounded; the 14th pin of the second IR2113S chip is connected with the pole electrode of the transistor Q4 and one end of the resistor 35 at the same time, one end of the resistor 35 is also connected with the pole electrode of the transistor Q4, and the other end of the resistor 35 is grounded.

[0014] Further, it further comprises: the P1 port is further connected with a 5V and a 12V power supply at the same time.

[0015] The utility model has the advantages and beneficial effects that:

[0016] Firstly, in the utility model, the push-off circuit adopts an LM393 chip, the LM393 chip compares the voltage value collected from the main circuit with the voltage of resistance voltage division, thereby judging whether the main circuit is overcurrent, and the safety of the contact resistance tester can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A structural schematic diagram of the contact resistance tester is provided in the utility model;

[0018] Figure 2 A circuit schematic diagram of the contact resistance tester is provided in the utility model. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model below.

[0020] Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the claimed utility model, but only represents selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the utility model.

[0021] Embodiments

[0022] The utility model provides a kind of contact resistance tester as Figure 1 And 2 As shown in a kind of contact resistance tester, device includes: sine wave inverter generator module, drive module, comparator module and push circuit module;

[0023] Sine wave inverter generator module is connected with push circuit module, push circuit module is connected with drive module, SPWM pulse width modulation waveform is exported through push circuit module by the output port of sine wave inverter generator module, is input into drive module;

[0024] Sine wave inverter generator module is connected with comparator module, comparator module is used to collect the voltage value flowing through sine wave inverter generator module, and judge whether contact resistance tester is overcurrent.

[0025] Sine wave inverter generator module includes EG8010 chip;Drive module includes two I R2113S chips;Comparator module includes LM393 chip.

[0026] EG8010 chip is the pure sine wave inverter generator chip with dead zone control, is applied to DC-AC single-stage power frequency transformer boost conversion architecture, is connected with 12MHz crystal oscillator, can realize the sine wave inverter special chip of high precision, distortion and harmonic is very small.EG8010 chip adopts CMOS technology, internal integration SPWM sine generator, dead zone time control circuit, amplitude factor multiplier, soft start circuit, protection circuit, RS232 serial communication interface and other functions.

[0027] The IR2113S chip is a high-side and low-side gate driver chip. The main function of the chip in the circuit is to switch control the MOS tube after the modulated switching waveform output by the EG8010 chip is driven by the IR2113S chip. The IR2113S chip has a driving capacity of 2.5A, can realize the fast switching of the MOS at a lower voltage, and ensure the normal modulation of the SPWM. The IR2113S chip can simplify the circuit design, reduce the number of external components, and improve the reliability and efficiency of the system. The IR2113S chip includes an under-voltage lockout function of two channels, which can prevent the chip from malfunctioning when the power voltage is insufficient, and ensure the reliability of the system. The chip also has a cycle trigger shutdown logic, which can realize the edge trigger shutdown of each cycle and improve the control accuracy.

[0028] The LM393 chip is a dual-voltage comparator integrated circuit. The LM393 chip includes two independent comparator modules. The main function of the chip in the circuit is to detect the overcurrent of the inverter module output. The current signal collected by the I FB pin is compared with the 5v divided signal, and the output level of the chip is applied to the EG8010 chip to realize the switching control of the output SPWM waveform.

[0029] The specific circuit diagram of the contact resistance tester can be referred to Figure 2 , and the following is part of the connection relationship.

[0030] The 30th pin of the EG8010 chip is connected to one end of the resistor 32 and the emitter of the transistor Q2. The 29th pin of the EG8010 chip is connected to one end of the resistor 30 and the emitter of the transistor Q3. The 28th pin of the EG8010 chip is connected to one end of the resistor 36 and the emitter of the transistor Q4. The 27th pin of the EG8010 chip is connected to one end of the resistor 34 and the emitter of the transistor Q5. The base of the transistor Q2 is connected to the other end of the resistor 30, and the collector of the transistor Q2 is used as the output terminal. The base of the transistor Q3 is connected to the other end of the resistor 32, and the collector of the transistor Q3 is used as the output terminal. The base of the transistor Q4 is connected to the other end of the resistor 34, and the collector of the transistor Q4 is used as the output terminal. The base of the transistor Q5 is connected to the other end of the resistor 36, and the collector of the transistor Q5 is used as the output terminal.

[0031] The 32th pin, the 18th pin, the 19th pin, the 20th pin, the 21th pin and the 16th pin of the EG8010 chip are grounded; the 17th pin of the EG8010 chip is connected with a 5v power supply; the 1st pin of the EG8010 chip is connected with a 5v power supply; the 26th pin of the EG8010 chip is connected with one end of the capacitor C9, and the other end of the capacitor C9 is grounded; the 26th pin of the EG8010 chip is connected with one end of the capacitor C10, and the other end of the capacitor C10 is grounded; the capacitor C10 and the capacitor C9 are connected with a 5V power supply; the 8th pin of the EG8010 chip is connected with the negative electrode of the diode D1, the positive electrode of the diode D1 is connected with one end of the resistor 1, and the other end of the resistor 1 is connected with a 5v power supply; the 9th pin of the EG8010 chip is connected with one end of the capacitor C1, the 12th pin of the EG8010 chip is connected with the capacitor C9, the relay Y1 is connected with the other end of the capacitor C9 and the other end of the capacitor C1 respectively, the 10th pin of the EG8010 chip is connected with one end of the relay Y1, the 11th pin of the EG8010 chip is connected with the other end of the relay Y1, the 12th pin of the EG8010 chip is also grounded, the 13th pin of the EG8010 chip is connected with one end of the capacitor C15, the other end of the capacitor C15 is grounded, the 13th pin of the EG8010 chip is also connected with the resistor 2, the other end of the resistor 2 is connected with the P1 port; the 15th pin of the EG8010 chip is connected with one end of the capacitor C16, the other end of the capacitor C16 is grounded, the 15th pin of the EG8010 chip is connected with one end of the resistor 3, the other end of the resistor 3 is connected with the P1 port, the other end of the resistor 3 is also connected with one end of the resistor 8, the other end of the resistor 8 is grounded; the 14th pin of the EG8010 chip is connected with one end of the capacitor C24, the other end of the capacitor C24 is grounded, the 14th pin of the EG8010 chip is also connected with one end of the resistor 38, the other end of the resistor 38 is connected with the capacitor C21, the other end of the resistor 38 is connected with one end of the resistor 7, the other end of the resistor 7 is connected with the P1 port, the other end of the capacitor C21 is grounded, and the 7th pin of the EG8010 chip is connected with the P1 port.

[0032] The first pin of the LM393 chip is connected with one end of the resistor 4, the other end of the resistor 4 is grounded, the first pin of the LM393 chip is also connected with the 13th pin of the first IR2113S chip, the first pin of the LM393 chip is also connected with the 13th pin of the second IR2113S chip, the first pin of the LM393 chip is also connected with one end of the resistor 26, the other end of the resistor 26 is connected with the third pin and the sixth pin of the LM393 chip at the same time; the second pin of the LM393 chip is connected with the fifth pin of the LM393 chip, the second pin of the LM393 chip is also connected with one end of the resistor 5, the second pin of the LM393 chip is also connected with one end of the resistor 6, the other end of the resistor 6 is grounded, and the capacitor C20 is connected externally, the other end of the resistor 5 is connected with one end of the capacitor C18 and the capacitor C17 at the same time, the other end of the capacitor C18 and the capacitor C17 is grounded; the third pin of the LM393 chip is connected with the sixth pin of the LM393 chip; the fourth pin of the LM393 chip is grounded; the sixth pin of the LM393 chip is connected with one end of the resistor 38, one end of the capacitor C21 and one end of the resistor 7 at the same time, the other end of the resistor 7 is connected with the P1 port; the eighth pin of the LM393 chip is connected with one end of the resistor 5, the capacitor C18 and the capacitor C17 at the same time, one end of the capacitor C18 and the capacitor C17 is connected with the 5V power supply externally.

[0033] The first IR2113S chip (in the Figure 2The first pin of the first IR2113S chip is connected with the P1 port; the second pin of the first IR2113S chip and the 15th pin of the first IR2113S chip are grounded; the third pin of the first IR2113S chip is connected with one end of the capacitor C3, one end of the capacitor C4 and the anode of the diode D2, the other end of the capacitor C3 and the other end of the capacitor C4 are grounded, one end of the capacitor C3 and one end of the capacitor C4 are also connected with a 12V power supply, the anode of the diode D2 is connected with one end of the capacitor C2 and the seventh pin of the first IR2113S chip, the other end of the capacitor C2 is connected with the P1 port; the eighth pin of the first IR2113S chip is connected with the P1 port; the 11th pin of the first IR2113S chip is connected with one end of the capacitor C5 and one end of the capacitor C6, the other end of the capacitor C5 and the other end of the capacitor C6 are connected and grounded, one end of the capacitor C5 and one end of the capacitor C6 are connected with a 5V power supply; the 12th pin of the first IR2113S chip is connected with the base electrode of the transistor Q3 and one end of the resistor R33, one end of the resistor R33 is also connected with the base electrode of the transistor Q3, the other end of the resistor R33 is grounded; the 14th pin of the first IR2113S chip is connected with the base electrode of the transistor Q2 and one end of the resistor R31, one end of the resistor R31 is also connected with the base electrode of the transistor Q2, the other end of the resistor R31 is grounded.

[0034] The second IR2113S chip (in the middle and upper part of the figure) Figure 2The first pin of the second IR2113S chip is connected with the P1 port; the second pin of the second IR2113S chip and the 15th pin of the second IR2113S chip are grounded; the third pin of the second IR2113S chip is connected with one end of the capacitor C11, one end of the capacitor C12 and the anode of the diode D3, the other end of the capacitor C11 and the other end of the capacitor C12 are grounded, one end of the capacitor C11 and one end of the capacitor C12 are also connected with a 12V power supply, the anode of the diode D3 is also connected with one end of the capacitor C8 and the seventh pin of the second IR2113S chip, the other end of the capacitor C8 is connected with the P1 port; the eighth pin of the second IR2113S chip is connected with the P1 port; the 11th pin of the second IR2113S chip is connected with one end of the capacitor C13 and one end of the capacitor C14, the other end of the capacitor C13 and the other end of the capacitor C14 are grounded, one end of the capacitor C13 and one end of the capacitor C14 are also connected with a 5V power supply; the 12th pin of the second IR2113S chip is connected with the base electrode of the transistor Q5 and one end of the resistor 37, one end of the resistor 37 is also connected with the base electrode of the transistor Q5, the other end of the resistor 37 is grounded; the 14th pin of the second IR2113S chip is connected with the base electrode of the transistor Q4 and one end of the resistor 35, one end of the resistor 35 is also connected with the base electrode of the transistor Q4, the other end of the resistor 35 is grounded.

[0035] The P1 port is also connected with a 5V and a 12V power supply.

[0036] The specific working process is as follows: the pins 4 and 5 of the EG8010 chip are serial ports, after receiving the serial port instructions of the external single-chip microcomputer, the internal register looks up the table to output the corresponding SPWM pulse width modulation waveform. The SPWM pulse width modulation waveform is output through OUT1, OUT2, OUT3 and OUT4, and enters the LI N and HIN input terminals of the driving chip IR2113S after passing through the push-pull circuit.

[0037] The internal circuits of the IR2113S chip output the input OUT1, OUT2, OUT3 and OUT4 waveforms after driving enhancement and bootstrap voltage boosting through the HO and LO pins, and the HO and LO pin outputs switch control the four MOS tubes of the inverter main circuit.

[0038] The LM393 chip compares the main circuit sampling voltage value with the voltage of the resistance voltage divider, so as to judge whether the main circuit is overcurrent, when the main circuit sampling voltage value is greater than the resistance voltage, the comparator pin 101 outputs low level and pulls down the output of the IR2113S chip through the pin SD, so as to turn off the HO and LO pin outputs and stop the inverter output.

[0039] The preferred embodiments of the present application have been described above with the preferred embodiments, but are not intended to limit the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A contact resistance tester characterized by, The device comprises: a sine wave inverter generator module, a driving module, a comparator module and a push-pull circuit module; The sine wave inverter generator module is connected with the push-pull circuit module, the push-pull circuit module is connected with the driving module, and SPWM pulse width modulation waveforms are input into the driving module through the output port of the sine wave inverter generator module and the push-pull circuit module. The sine wave inverter generator module is connected with the comparator module, and the comparator module is used for collecting the voltage value flowing through the sine wave inverter generator module and judging whether the contact resistance tester is overcurrent.

2. The contact resistance tester of claim 1, wherein, The device comprises: The sine wave inverter generator module comprises an EG8010 chip, the driving module comprises two IR2113S chips, and the comparator module comprises an LM393 chip.

3. The contact resistance tester of claim 2, wherein, The device comprises: The 30th pin of the EG8010 chip is connected with one end of the resistor 32 and the emitter of the transistor Q2; the 29th pin of the EG8010 chip is connected with one end of the resistor 30 and the emitter of the transistor Q3; the 28th pin of the EG8010 chip is connected with one end of the resistor 36 and the emitter of the transistor Q4; the 27th pin of the EG8010 chip is connected with one end of the resistor 34 and the emitter of the transistor Q5; the base of the transistor Q2 is connected with the other end of the resistor 30, and the collector of the transistor Q2 is used as an output end; the base of the transistor Q3 is connected with the other end of the resistor 32, and the collector of the transistor Q3 is used as an output end; the base of the transistor Q4 is connected with the other end of the resistor 34, and the collector of the transistor Q4 is used as an output end; The base of the transistor Q5 is connected with the other end of the resistor 36, and the collector of the transistor Q5 is used as an output end.

4. The contact resistance tester of claim 2, wherein, The device further comprises: The 32th pin, the 18th pin, the 19th pin, the 20th pin, the 21th pin and the 16th pin of the EG8010 chip are grounded; the 17th pin of the EG8010 chip is connected with a 5v power supply; the 1st pin of the EG8010 chip is connected with a 5v power supply; the 26th pin of the EG8010 chip is connected with one end of the capacitor C9, and the other end of the capacitor C9 is grounded; the 26th pin of the EG8010 chip is connected with one end of the capacitor C10, and the other end of the capacitor C10 is grounded; the capacitor C10 and the capacitor C9 are connected with a 5v power supply; the 8th pin of the EG8010 chip is connected with the negative electrode of the diode D1, the positive electrode of the diode D1 is connected with one end of the resistor 1, and the other end of the resistor 1 is connected with a 5v power supply; the 9th pin of the EG8010 chip is connected with one end of the capacitor C1, the 12th pin of the EG8010 chip is connected with the capacitor C9, the relay Y1 is connected with the other end of the capacitor C9 and the other end of the capacitor C1, the 10th pin of the EG8010 chip is connected with one end of the relay Y1, the 11th pin of the EG8010 chip is connected with the other end of the relay Y1, the 12th pin of the EG8010 chip is also grounded, the 13th pin of the EG8010 chip is connected with one end of the capacitor C15, the other end of the capacitor C15 is grounded, the 13th pin of the EG8010 chip is also connected with the resistor 2, the other end of the resistor 2 is connected with the P1 port; the 15th pin of the EG8010 chip is connected with one end of the capacitor C16, the other end of the capacitor C16 is grounded, the 15th pin of the EG8010 chip is connected with one end of the resistor 3, the other end of the resistor 3 is connected with the P1 port, the other end of the resistor 3 is also connected with one end of the resistor 8, the other end of the resistor 8 is grounded; the 14th pin of the EG8010 chip is connected with one end of the capacitor C24, the other end of the capacitor C24 is grounded, the 14th pin of the EG8010 chip is also connected with one end of the resistor 38, the other end of the resistor 38 is connected with the capacitor C21, the other end of the resistor 38 is connected with one end of the resistor 7, the other end of the resistor 7 is connected with the P1 port, the other end of the capacitor C21 is grounded, and the 7th pin of the EG8010 chip is connected with the P1 port.

5. The contact resistance tester of claim 2, wherein, Also includes: The first pin of the LM393 chip is connected with one end of the resistor 4, the other end of the resistor 4 is grounded, the first pin of the LM393 chip is also connected with the 13th pin of the first IR2113S chip, the first pin of the LM393 chip is also connected with the 13th pin of the second IR2113S chip, the first pin of the LM393 chip is also connected with one end of the resistor 26, the other end of the resistor 26 is connected with the third pin and the sixth pin of the LM393 chip at the same time; the second pin of the LM393 chip is connected with the fifth pin of the LM393 chip, the second pin of the LM393 chip is also connected with one end of the resistor 5, the second pin of the LM393 chip is also connected with one end of the resistor 6, the other end of the resistor 6 is grounded, and the capacitor C20 is connected outside, the other end of the resistor 5 is connected with one end of the capacitor C18 and the capacitor C17 at the same time, the other end of the capacitor C18 and the capacitor C17 is grounded; the third pin of the LM393 chip is connected with the sixth pin of the LM393 chip; the fourth pin of the LM393 chip is grounded; the sixth pin of the LM393 chip is connected with one end of the resistor 38, one end of the capacitor C21 and one end of the resistor 7 at the same time, the other end of the resistor 7 is connected with the P1 port; the eighth pin of the LM393 chip is connected with one end of the resistor 5, the capacitor C18 and the capacitor C17 at the same time, one end of the capacitor C18 and the capacitor C17 is connected with the 5V power supply outside.

6. The contact resistance tester of claim 2, wherein, Also including: the first pin of the first IR2113S chip is connected with the P1 port; the second pin of the first IR2113S chip and the 15th pin of the first IR2113S chip are grounded; the third pin of the first IR2113S chip is connected with one end of the capacitor C3, one end of the capacitor C4 and the positive electrode of the diode D2 at the same time, the other end of the capacitor C3 and the other end of the capacitor C4 are grounded, one end of the capacitor C3 and one end of the capacitor C4 are also connected with the 12V power supply outside, the positive electrode of the diode D2 is also connected with one end of the capacitor C2, the seventh pin of the first IR2113S chip, the other end of the capacitor C2 is connected with the P1 port; the eighth pin of the first IR2113S chip is connected with the P1 port; the eleventh pin of the first IR2113S chip is connected with one end of the capacitor C5 and one end of the capacitor C6 at the same time, the other end of the capacitor C5 and the other end of the capacitor C6 are connected at the same time and grounded, one end of the capacitor C5 and one end of the capacitor C6 are connected with the 5V power supply outside; the twelfth pin of the first IR2113S chip is connected with the pole electrode of the transistor Q3 and one end of the resistor 33 at the same time, one end of the resistor 33 is also connected with the pole electrode of the transistor Q3, the other end of the resistor 33 is grounded; the fourteenth pin of the first IR2113S chip is connected with the pole electrode of the transistor Q2 and one end of the resistor 31 at the same time, one end of the resistor 31 is also connected with the pole electrode of the transistor Q2, the other end of the resistor 31 is grounded.

7. The contact resistance tester of claim 2, wherein, Also including: The first pin of the second IR2113S chip is connected with the P1 port; the second pin of the second IR2113S chip and the 15th pin of the second IR2113S chip are grounded; the third pin of the second IR2113S chip is connected with one end of the capacitor C11, one end of the capacitor C12 and the anode of the diode D3 at the same time, the other end of the capacitor C11 and the other end of the capacitor C12 are grounded, one end of the C11 and one end of the capacitor C12 are also connected with a 12V power supply, the anode of the diode D3 is connected with one end of the capacitor C8 and the seventh pin of the second IR2113S chip at the same time, the other end of the capacitor C8 is connected with the P1 port; the eighth pin of the second IR2113S chip is connected with the P1 port; the 11th pin of the second IR2113S chip is connected with one end of the capacitor C13 and one end of the capacitor C14 at the same time, the other end of the capacitor C13 and the other end of the capacitor C14 are connected and grounded at the same time, one end of the capacitor C13 and one end of the capacitor C14 are connected with a 5V power supply; the 12th pin of the second IR2113S chip is connected with the pole electrode of the transistor Q5 and one end of the resistor 37 at the same time, one end of the resistor 37 is also connected with the pole electrode of the transistor Q5, and the other end of the resistor 37 is grounded; the 14th pin of the second IR2113S chip is connected with the pole electrode of the transistor Q4 and one end of the resistor 35 at the same time, one end of the resistor 35 is also connected with the pole electrode of the transistor Q4, and the other end of the resistor 35 is grounded.

8. The contact resistance tester of claim 4, wherein, Also comprising: The P1 port is also connected with a 5V and a 12V power supply at the same time.

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