Pin electrical performance test circuit and method

Abstract

The present invention discloses a circuit and method for testing the electrical performance of plugs. The circuit includes: a voltage sampling unit for collecting the input voltage of the pin to be tested; a current sampling unit for collecting the input current of other pins; at least one pin configuration unit for connecting the pin to be tested to the voltage sampling unit and other pins to the current sampling unit according to a configuration signal to obtain the input voltage and input current; and a main control unit for outputting the configuration signal according to a test item and calculating the insulation resistance or DC resistance of the pin to be tested based on the input voltage and input current. Implementing the present invention can automatically test the insulation resistance and DC resistance of each pin in a plug, significantly reducing the number and time of tests, and avoiding meaningless insulation resistance tests between conductive pins. In conjunction with a conversion connector, it can test plugs of any type, demonstrating strong versatility.

Description

Technical Field

[0001] The present invention relates to the technical field of equipment detection, and in particular to a pin electrical performance testing circuit and method. Background Art

[0002] During nuclear power plant maintenance, it's necessary to test each port on medium-voltage circuit breakers and contactors. This means testing the DC resistance and insulation resistance of the corresponding aviation plug pins. Due to a lack of dedicated testing tools, handheld insulation resistance testers are currently the only option. Each pin can only be measured individually using a handheld insulation resistance tester, and only two pins can be tested at a time. Some plugs have as many as 58 pins, and the number of circuit breakers and contactors that need to be inspected at any one time is large. This ultimately results in a heavy measurement workload and can easily delay maintenance schedules. Furthermore, some pins are conductive when the circuit breaker is open, some when closed, and some always conductive. Manual measurement requires checking the status of each pin individually, which can lead to human error, repeated measurements, and missed measurements. This not only increases the maintenance workload but can also prevent the timely detection of abnormal equipment, impacting the normal operation of the nuclear power plant. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a pin electrical performance testing circuit and method in response to at least one defect in the prior art.

[0004] The technical solution adopted by the present invention to solve the technical problem is to construct a pin electrical performance test circuit, including:

[0005] Voltage sampling unit, used to collect the input voltage of the pin to be tested;

[0006] Current sampling unit, used to collect input current of other pins;

[0007] At least one pin configuration unit, configured to connect the pin to be tested to the voltage sampling unit and connect other pins to the current sampling unit according to a configuration signal, so as to obtain the input voltage and input current;

[0008] The main control unit is used to output the configuration signal according to the test item, and calculate the insulation resistance or DC resistance of the pin to be tested according to the input voltage and input current.

[0009] In the pin electrical performance test circuit of the present invention, the pin electrical performance test circuit further includes a test power supply;

[0010] The main control unit also outputs a power configuration instruction according to the test item; the voltage sampling unit sets its voltage sampling end and the output channel of the test power supply according to the power configuration instruction to obtain the high-voltage constant-voltage signal required for the insulation resistance test or the low-voltage constant-voltage signal required for the DC resistance test.

[0011] In the pin electrical performance test circuit described in the present invention, the voltage sampling unit includes a second relay, a fourth diode, a second switch tube, an eleventh resistor, a twelfth resistor, a sixth voltage-stabilizing tube, a sixth resistor, a ninth resistor, and a tenth resistor;

[0012] One end of the excitation coil of the second relay is connected to the first DC voltage and the cathode of the fourth diode, the other end of the excitation coil of the second relay is connected to the anode of the fourth diode and the input end of the second switching tube, the output end of the second switching tube is grounded, the control end of the second switching tube is connected to the second end of the eleventh resistor, and the first end of the eleventh resistor is connected to the main control unit as the power configuration instruction input end;

[0013] The second common contact of the second relay is connected to the pin configuration unit as a test voltage input end of the voltage sampling unit, the second normally closed contact of the second relay is connected to the low voltage constant voltage signal output end of the test power supply, and the second normally open contact of the second relay is connected to the high voltage constant voltage signal output end of the test power supply via the twelfth resistor;

[0014] The first common contact of the second relay is connected to the main control unit and the cathode of the sixth voltage-stabilizing diode as a voltage sampling signal output end, the anode of the sixth voltage-stabilizing diode is grounded, the first normally closed contact of the second relay is connected to the pin configuration unit via the sixth resistor as a first voltage sampling end, the first normally open contact of the second relay is connected to the first voltage sampling end via the ninth resistor as a second voltage sampling end, and the second voltage sampling end is also connected to the ground via the tenth resistor.

[0015] In the pin electrical performance test circuit of the present invention, the pin electrical performance test circuit further includes a constant current unit; the constant current unit is connected between the voltage sampling unit and the pin configuration unit.

[0016] In the pin electrical performance test circuit of the present invention, the current sampling unit includes a first relay, a first switch tube, a fifth resistor, a third resistor, a fourth resistor, a seventeenth resistor and a fifth voltage regulator tube;

[0017] One end of the excitation coil of the first relay is connected to a first DC voltage, the other end of the excitation coil of the first relay is connected to the input end of the first switching tube, the output end of the first switching tube is grounded, the control end of the first switching tube is connected to the first end of the fifth resistor, and the second end of the fifth resistor is connected to the main control unit as a current sampling configuration signal input end;

[0018] The first common contact of the first relay is connected to the pin configuration unit and the second normally open contact of the first relay as a test current input end of the current sampling unit. The test current input end is also connected to the first end of the fourth resistor via the third resistor. The first end of the fourth resistor is also connected to the first normally closed contact and the second normally closed contact of the first relay. The second end of the fourth resistor is grounded. The second common contact of the first relay is connected to the first end of the seventeenth resistor. The second end of the seventeenth resistor is connected to the main control unit as a current sampling signal output end. The second end of the seventeenth resistor is also connected to the cathode of the fifth voltage regulator tube, and the anode of the fifth voltage regulator tube is grounded.

[0019] In the pin electrical performance test circuit of the present invention, the pin electrical performance test circuit further includes an analog-to-digital conversion unit, which includes an analog-to-digital conversion chip, a third voltage regulator, a fifteenth resistor, a second crystal oscillator, a fifth capacitor, a sixth capacitor, a fourteenth resistor, and an eighth capacitor;

[0020] The reference voltage input terminal of the analog-to-digital conversion chip is connected to the cathode of the third voltage-stabilizing diode, and the anode of the third voltage-stabilizing diode is grounded. The reference voltage input terminal of the analog-to-digital conversion chip is also connected to the first DC voltage via the fifteenth resistor. The eighth capacitor is connected in parallel with the third voltage-stabilizing diode. The first and second clock signal input terminals of the analog-to-digital conversion chip are connected in parallel with the second crystal oscillator. The first end of the second crystal oscillator is connected to the ground via the sixth capacitor, and the second end of the second crystal oscillator is connected to the ground via the fifth capacitor. The first analog channel input terminal of the analog-to-digital conversion chip is connected to the current sampling signal output terminal of the current sampling unit, the second analog channel input terminal of the analog-to-digital conversion chip is connected to the voltage sampling signal output terminal of the voltage sampling unit, the first and second analog channel ground terminals of the analog-to-digital conversion chip are grounded, the communication clock input terminal, the communication output terminal, and the communication input terminal of the analog-to-digital conversion chip are connected to the main control unit, and the reset terminal of the analog-to-digital conversion chip is connected to the first DC voltage via the fourteenth resistor.

[0021] In the pin electrical performance test circuit of the present invention, each of the pin configuration units includes a configuration matrix unit and a matrix control unit;

[0022] Among them, the configuration matrix unit includes several relays; the first end of the excitation coil of each relay is connected to the matrix control unit, and the second end of the excitation coil of each relay is connected to the second DC voltage to control whether each relay is excited according to the configuration signal; the common contact of the relay is used to connect each pin one by one, the normally closed contact of the relay is connected to the test current input end of the current sampling unit, and the normally open contact of the relay is connected to the test voltage input end of the voltage sampling unit, and then the conduction relationship between the corresponding pin and the voltage sampling unit and the current sampling unit is controlled according to whether the relay is excited.

[0023] In the pin electrical performance test circuit of the present invention, the configuration signal includes a number of address signals and control signals;

[0024] The matrix control unit includes a number of D flip-flops and driver transistors corresponding to the number of the relays, and a pull-up unit; the clock input terminals of the D flip-flops are connected in parallel and serve as the address input terminals of the pin configuration unit for receiving an address signal so that the main control unit selects to control the matrix control unit, and the input terminals of the D flip-flops serve as the control signal input terminals of the pin configuration unit to receive the control signal so as to control the output signal of the D flip-flops;

[0025] The output end of each D trigger is connected to the control end of each driving tube in a one-to-one correspondence, and the control end of each driving tube is also connected to the first DC voltage via the pull-up unit. The output end of each driving tube is connected to the output end of the excitation coil of each relay in a one-to-one correspondence, and the output end of each driving tube is grounded. The input end of the excitation coil of each relay is connected to the second DC voltage, and then the corresponding relay is controlled to be excited according to the output signal of the D trigger.

[0026] In the pin electrical performance test circuit of the present invention, the pin electrical performance test circuit further includes:

[0027] The communication unit is connected to the main control unit and is used to obtain the test items output by the host computer and send the test data calculated by the main control unit to the host computer.

[0028] The present invention also provides a method for testing the electrical performance of a pin, comprising the following steps:

[0029] S10, setting at least one pin configuration unit;

[0030] S20. Generate a configuration signal according to the test item, and control the pin configuration unit through the configuration signal to connect the pin to be tested to the voltage sampling unit and other pins to the current sampling unit, so as to collect the input voltage of the pin to be tested and the input current of other pins;

[0031] S30. Calculate the insulation resistance or DC resistance of the pin to be tested according to the input voltage and input current.

[0032] The present invention has the following beneficial effects: it can realize automatic testing of the insulation resistance and DC resistance of each pin of the plug, greatly reducing the number of tests and time; it can also identify in advance the conductivity between the pins based on pre-stored information of the plug, and skip the pins that are originally conductive or have a small DC resistance during testing, thereby avoiding meaningless insulation resistance testing between conductive pins; and when performing the insulation resistance test, when it is identified that the insulation resistance of the pin to be tested is significantly lower than the insulation resistance standard value, it automatically switches to the output channel of the test power supply to perform DC resistance measurement; in conjunction with a conversion connector, it can perform insulation resistance testing and DC resistance testing on the pins of any type of plug, and has strong versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0034] Figure 1 This is a structural diagram of the pin electrical performance test circuit provided by the present invention;

[0035] Figure 2 This is an example diagram of the test principle of the pin electrical performance test circuit provided by the present invention;

[0036] Figure 3 This is a circuit diagram of a voltage sampling unit in a pin electrical performance test circuit provided by the present invention;

[0037] Figure 4 This is a connection diagram of a constant current unit in a pin electrical performance test circuit provided by the present invention;

[0038] Figure 5 This is a circuit diagram of a current sampling unit in a pin electrical performance test circuit provided by the present invention;

[0039] Figure 6 This is a circuit diagram of an analog-to-digital conversion unit in a pin electrical performance test circuit provided by the present invention;

[0040] Figure 7 is a circuit diagram of a matrix unit in a pin configuration unit provided by the present invention;

[0041] Figure 8 This is a circuit diagram of a matrix control unit in a pin configuration unit provided by the present invention;

[0042] Figure 9 This is a circuit diagram of the main control unit in the pin electrical performance test circuit provided by the present invention;

[0043] Figure 10 It is a flow chart of the pin electrical performance testing method provided by the present invention. DETAILED DESCRIPTION

[0044] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0045] refer to Figure 1 The present invention provides a pin electrical performance test circuit, including a voltage sampling unit 1, a current sampling unit 2, a main control unit 3 and at least one pin configuration unit 4.

[0046] The voltage sampling unit 1 is used to collect the input voltage of the pin to be tested.

[0047] Current sampling unit 2 is used to collect the input current of other pins.

[0048] At least one pin configuration unit 4 is configured to connect the pin to be tested to the voltage sampling unit 1 and the other pins to the current sampling unit 2 according to a configuration signal, so as to obtain input voltage and input current. The other pins are pins other than the pin to be tested. For example, assuming a plug includes pins 1 to 10, if the pin to be tested is pin 1, then the other pins correspond to pins 2 to 10. If the pins to be tested are pins 1 and 3, then the other pins correspond to pins 2 and 4 to 10. In some embodiments, some pins in the plug are interconnected, correspond to the two ends of the excitation coil of a relay, or are connected through a resistor, which may affect the insulation resistance measurement. Therefore, when measuring the insulation resistance, these pins will be simultaneously defined as the pins to be measured; correspondingly, when measuring the DC resistance of these pins, these pins are defined separately. For example, when measuring the DC resistance of the two ends of the excitation coil of a relay, the pin at one end of the excitation coil needs to be defined as the pin to be measured, and the pin at the other end needs to be defined as the other pins.

[0049] Main control unit 3 is used to output configuration signals based on test items and calculate the insulation resistance or DC resistance of the pin under test based on the input voltage and input current. Test items include insulation resistance and DC resistance tests for any pin. During testing, the main control circuit obtains connection information for each pin based on pre-stored information about the plug under test. It then generates configuration signals based on the test items, controlling the connection of the pin under test to voltage sampling unit 1 and the connection of other pins to current sampling unit 2. Taking a plug as an example, assuming that the pre-stored information of the plug is as follows: including pins 1 to 10, wherein pins 1 and 2 correspond to the two ends of the relay excitation coil, respectively, and pins 1 and 2 have no direct connection with pins 3 to 10. That is, based on the pre-stored information, the existing conductivity between the pins can be identified in advance, and pins that are originally conductive or have low DC resistance are skipped during testing, thereby avoiding meaningless insulation resistance testing between conductive pins; when the test item is to measure the insulation resistance of pin 1, the configuration signal output by the main control unit 3 is used to control the pin configuration unit 4 to connect pins 1 and 2 to the voltage sampling unit 1 at the same time, and to connect pins 3 to 10 to the current sampling unit 2; when the test item is to measure the DC resistance of pin 1, the configuration signal output by the main control unit 3 is used to control the pin configuration unit 4 to connect pin 1 to the voltage sampling unit 1 and to connect pins 2 to 10 to the current sampling unit 2.

[0050] refer to Figure 2 The test principle of the pin electrical performance test circuit is as follows: 1. The input end of the voltage sampling unit 1 (corresponding to The first end of the The second end of the voltage sampling unit 1 is connected in parallel to the positive and negative poles of the input power supply, the input end of the voltage sampling unit 1 is also connected to the pin configuration unit 4, and the control circuit is connected to the voltage sampling end of the voltage sampling unit 1 (corresponding to The second end or the first end), according to Figure 2 It can be deduced that the input voltage (1); among them, is the resistor The resistance value, is the resistor The resistance value, is the voltage value of the voltage sampling terminal; 2. The current sampling terminal of the current sampling unit 2 (corresponding to The first end of the current sampling unit 2 is connected to the pin configuration unit 4, and the output end of the current sampling unit 2 (corresponding to The second end of the grounded, it can be deduced that the input current (2); among them is the resistor The resistance value, is the voltage value of the current sampling terminal; 3. During the test, the pin configuration unit 4 controls the pin N1 to be tested to be connected to the input terminal of the voltage sampling unit 1 and the other pin N2 to be connected to the current sampling unit 2 according to the configuration signal. The main control circuit calculates the pin N1 to be tested, the other pins N2 and the resistance according to Ohm's law based on the resistance of the voltage sampling terminal and the current sampling terminal and formulas (1) and (2). The sum of the resistances, minus the resistance , the resistance RX between the pin under test N1 and the other pin N2 can be calculated. This resistance RX corresponds to the insulation resistance or DC resistance. Furthermore, when testing insulation resistance, although the pin under test N1 and the other pin N2 are not directly connected, leakage current exists between the pins, and this leakage current corresponds to the input current.

[0051] Since a higher input voltage is required to ensure the accuracy of the test when testing insulation resistance, if the input voltage is high, there is a risk of damage to the components connected between the pin to be tested and other pins when testing DC resistance. Therefore, in some embodiments, the pin electrical performance test circuit can also include a test power supply, which can be a dual-channel constant voltage power supply. Correspondingly, the main control unit 3 also outputs a power configuration instruction based on the test item; the voltage sampling unit 1 sets its voltage sampling terminal and the output channel of the test power supply according to the power configuration instruction to obtain the high-voltage constant voltage signal required for the insulation resistance test or the low-voltage constant voltage signal required for the DC resistance test. Furthermore, when performing an insulation resistance test, if the calculated resistance value is significantly lower than the insulation resistance standard value, it indicates that the pre-stored information input to the plug to be tested may be incorrect. At this time, the main control unit 3 uses the power configuration instruction to switch the output channel of the test power supply to a low-voltage constant voltage signal and simultaneously switches to the DC resistance test to test the DC resistance of the pin to be tested.

[0052] In some embodiments, as Figure 3 As shown, the voltage sampling unit 1 includes a second relay KM2, a fourth diode D4, a second switch tube Q2, an eleventh resistor R11, a twelfth resistor R12, a sixth voltage regulator tube D6, a sixth resistor R6, a ninth resistor R9, and a tenth resistor R10. The second switch tube Q2 can be an NPN transistor, whose base corresponds to the control terminal, its emitter corresponds to the output terminal, and its collector corresponds to the input terminal. Regarding the second relay KM2, the first and second pins of the second relay KM2 correspond to the two ends of the excitation coil, the third, fifth, and seventh pins of the second relay KM2 correspond to the first normally closed contact, the first common contact, and the first normally open contact, respectively, and the fourth, sixth, and eighth pins of the second relay KM2 correspond to the second normally closed contact, the second common contact, and the second normally open contact, respectively.

[0053] Specifically, one end of the excitation coil of the second relay KM2 is connected to the first DC voltage and the cathode of the fourth diode D4, the other end of the excitation coil of the second relay KM2 is connected to the anode of the fourth diode D4 and the input end of the second switch tube Q2, the output end of the second switch tube Q2 is grounded, the control end of the second switch tube Q2 is connected to the second end of the eleventh resistor R11, the first end of the eleventh resistor R11 is connected to the main control unit 3 as the power configuration instruction input end, the second common contact of the second relay KM2 is connected to the pin configuration unit 4 as the test voltage input end of the voltage sampling unit 1, and the second normally closed contact of the second relay KM2 is connected to the test power supply The low-voltage constant-voltage signal output end of the test power supply is connected to the second normally-open contact of the second relay KM2 via the twelfth resistor R12. The first common contact of the second relay KM2 is connected to the main control unit 3 and the cathode of the sixth voltage-stabilizing tube D6 as the voltage sampling signal output end. The anode of the sixth voltage-stabilizing tube D6 is grounded. The first normally-closed contact of the second relay KM2 is connected to the pin configuration unit 4 via the sixth resistor R6 as the first voltage sampling end. The first normally-open contact of the second relay KM2 is connected to the first voltage sampling end via the ninth resistor R9 as the second voltage sampling end. The second voltage sampling end is also connected to the ground via the tenth resistor R10.

[0054] In some embodiments, as Figure 3 As shown, the voltage sampling unit 1 further includes a seventh resistor R7, an eighth resistor R8, and a fourth capacitor C4. Specifically, the first normally closed contact of the second relay KM2 is connected to the second end of the sixth resistor R6 via the eighth resistor R8 and the seventh resistor R7, respectively. The sixth resistor R6 is connected to the pin configuration unit 4. The eighth resistor R8 and the seventh resistor R7 function to divide the voltage of the sixth resistor R6 and also improve the flexibility of adjusting the resistance between the pin configuration unit 4 and the first normally closed contact of the second relay KM2. The fourth capacitor C4 acts as a filter capacitor and is connected in parallel with the sixth voltage regulator diode D6.

[0055] refer to Figure 3 The working principle of the voltage sampling unit 1 is as follows: when testing DC resistance, the power configuration command output by the main control unit 3 is low, the second switch tube Q2 is turned off, and the second relay KM2 is demagnetized. That is, the low-voltage constant voltage signal output by the test power supply is input to the pin configuration unit 4 via the second common contact and the second normally closed contact of the second relay KM2 (during measurement, the pin configuration unit 4 controls this end to be conductive with the pin to be tested), thereby providing the low-voltage constant voltage signal required for DC resistance testing. At the same time, the first common contact and the first normally closed contact of the second relay KM2 are closed. At this time, the voltage sampling position of the main control unit 3 is the first voltage sampling end (the first end of the ninth resistor R9);

[0056] When testing the insulation resistance, the power configuration instruction output by the main control unit 3 is high, the second switch tube Q2 is turned on, the second relay KM2 is energized, and the second common contact and the second normally open contact of the second relay KM2 are closed. That is, the high-voltage constant voltage signal output by the test power supply is input to the pin configuration unit 4 via the twelfth resistor R12, the second common contact and the second normally open contact of the second relay KM2 (during the test, the pin configuration unit 4 controls this end to be connected to the pin to be tested), thereby providing the high-voltage constant voltage signal required for the insulation resistance test. At the same time, the first common contact and the first normally open contact of the second relay KM2 are closed. At this time, the voltage sampling position of the main control unit 3 is the second voltage sampling end (the second end of the ninth resistor R9);

[0057] The distinction between the first and second voltage sampling terminals is because when testing insulation resistance, a high-voltage constant-voltage signal is input. If the impedance to ground at the voltage sampling terminal is too high, the voltage value distributed there will also be high, potentially damaging the downstream circuitry connected to the voltage sampling terminal. Therefore, when testing insulation resistance, sampling is performed at the second voltage sampling terminal (the second voltage sampling terminal has a lower impedance to ground than the first voltage sampling terminal). Furthermore, the sixth voltage-stabilizing diode D6 is used to clamp the voltage sampling signal input to the main control unit 3 to further protect the downstream circuitry. The fourth diode D4 serves as a freewheeling diode for the excitation coil of the second relay KM2.

[0058] In some embodiments, as Figure 4 As shown, the pin electrical performance test circuit also includes a constant current unit 5; the constant current unit 5 is connected between the voltage sampling unit 1 and the pin configuration unit 4. The constant current unit 5 is used to add a constant current characteristic to the constant voltage signal output by the test power supply, limiting the input current value of the constant voltage signal, thereby preventing damage to components connected between the pin under test and other pins due to overcurrent.

[0059] In some embodiments, as Figure 5 As shown, the current sampling unit 2 includes a first relay KM1, a first switching transistor Q1, a fifth resistor R5, a third resistor R3, a fourth resistor R4, a seventeenth resistor R17, and a fifth voltage-stabilizing transistor D5. Pins 1 and 2 of the first relay KM1 correspond to the two ends of the excitation coil, pins 3, 5, and 7 of the first relay KM12 correspond to the first normally closed contact, the first common contact, and the first normally open contact, respectively, and pins 4, 6, and 8 of the first relay KM1 correspond to the second normally closed contact, the second common contact, and the second normally open contact, respectively.

[0060] Specifically, one end of the excitation coil of the first relay KM1 is connected to the first DC voltage, the other end of the excitation coil of the first relay KM1 is connected to the input end of the first switch tube Q1, the output end of the first switch tube Q1 is grounded, the control end of the first switch tube Q1 is connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is connected to the main control unit 3 as the current sampling configuration signal input end, the first common contact of the first relay KM1 is connected to the pin configuration unit 4 and the second normally open contact of the first relay KM1 as the test current input end of the current sampling unit 2, the test current input end is also connected to the first end of the fourth resistor R4 via the third resistor R3, the first end of the fourth resistor R4 is also connected to the first normally closed contact and the second normally closed contact of the first relay KM1, the second end of the fourth resistor R4 is grounded, the second common contact of the first relay KM1 is connected to the first end of the seventeenth resistor R17, the second end of the seventeenth resistor R17 is connected to the main control unit 3 as the current sampling signal output end, the second end of the seventeenth resistor R17 is also connected to the cathode of the fifth voltage regulator tube D5, and the anode of the fifth voltage regulator tube D5 is grounded.

[0061] In some embodiments, as Figure 5 As shown, the current sampling unit 2 also includes a protection transistor D2 and a third capacitor C3. The protection transistor D2 can be an ESD diode or a TVS diode. Specifically, the first common contact of the first relay KM1 is connected to ground via the protection transistor D2. The third capacitor C3 serves as a filter capacitor and is connected in parallel with the fifth voltage regulator diode D5.

[0062] refer to Figure 5 The working principle of the current sampling unit 2 is as follows: Since the DC resistance of the pin is generally relatively small when testing, a smaller sampling resistor value can prevent the voltage of the current sampling signal from being too high and damaging the subsequent circuit. Therefore, when testing the DC resistance, the current sampling configuration signal output by the main control unit 3 is low, the first switch Q1 is turned off, the first relay KM1 is demagnetized, and the test current input terminal (during testing, the pin configuration unit 4 controls this terminal to be conductive with other pins) is connected to ground via the first common contact and the first normally closed contact of the first relay KM1, and the fourth resistor R4. At the same time, the first end of the fourth resistor R4 is connected to the first end of the seventeenth resistor R17 via the second common contact and the second normally closed contact of the first relay KM1. That is, at this time, the impedance of the test current input terminal to ground is the resistance value of the fourth resistor R4.

[0063] Since the insulation resistance of the pin is relatively large, a larger sampling resistor is required to relatively raise the voltage value of the current sampling signal so that it can be detected by the chip, which is also beneficial to improving the test accuracy. Therefore, when testing the insulation resistance, the current sampling configuration signal output by the main control unit 3 is at a high level, the first switch tube Q1 is turned on, the first relay KM1 is energized, and the first common contact and the first normally closed contact of the first relay KM1 are disconnected, which is equivalent to the test current input end (during the test, the pin configuration unit 4 controls this end to be connected to other pins) connected to the ground via the third resistor R3 and the fourth resistor R4. At the same time, the test current input end is connected to the first end of the seventeenth resistor R17 via the second normally open contact and the second common contact of the first relay KM1. That is, at this time, the impedance of the test current input end to ground is the sum of the resistance values ​​of the third resistor R3 and the fourth resistor R4.

[0064] In some embodiments, as Figure 6 As shown, the pin electrical performance test circuit also includes an analog-to-digital conversion unit, which is used to convert the voltage sampling signal and the current sampling signal into digital signals and input the converted digital signals to the main control unit 3. Furthermore, the analog-to-digital conversion unit includes an analog-to-digital conversion chip U2, a third voltage regulator diode U3, a fifteenth resistor R15, a second crystal oscillator X2, a fifth capacitor C5, a sixth capacitor C6, a fourteenth resistor R14, and an eighth capacitor C8. Among them, the model of the analog-to-digital conversion chip U2 can be AD7705; the 9th pin of the analog-to-digital conversion chip U2 corresponds to the reference voltage input terminal, its 2nd pin and 3rd pin correspond to the first clock signal input terminal and the second clock signal input terminal respectively, its 7th pin and 6th pin correspond to the first analog channel input terminal and the second analog channel input terminal respectively, its 8th pin and 11th pin correspond to the first analog channel ground terminal and the second analog channel ground terminal respectively, its 1st pin corresponds to the communication clock input terminal, its 13th pin corresponds to the communication output terminal, its 14th pin corresponds to the communication input terminal, and its 5th pin corresponds to the reset terminal.

[0065] Specifically, the reference voltage input terminal of the analog-to-digital conversion chip U2 is connected to the cathode of the third voltage regulator tube U3, the anode of the third voltage regulator tube U3 is grounded, the reference voltage input terminal of the analog-to-digital conversion chip U2 is also connected to the first DC voltage via the fifteenth resistor R15, the eighth capacitor C8 is connected in parallel with the third voltage regulator tube, the first and second clock signal input terminals of the analog-to-digital conversion chip U2 are connected in parallel with the second crystal oscillator X2, the first end of the second crystal oscillator X2 is connected to the ground via the sixth capacitor C6, and the second end of the second crystal oscillator X2 is connected to the ground via the fifth capacitor C5, the first analog channel input terminal of the analog-to-digital conversion chip U2 is connected to the current sampling signal output terminal of the current sampling unit 2, the second analog channel input terminal of the analog-to-digital conversion chip U2 is connected to the voltage sampling signal output terminal of the voltage sampling unit 1, the first and second analog channel ground terminals of the analog-to-digital conversion chip U2 are grounded, the communication clock input terminal, the communication output terminal and the communication input terminal of the analog-to-digital conversion chip U2 are connected to the main control unit 3, and the reset terminal of the analog-to-digital conversion chip U2 is connected to the first DC voltage via the fourteenth resistor R14.

[0066] In some embodiments, as Figure 6 As shown, the analog-to-digital conversion unit further includes a thirteenth resistor R13, a tenth capacitor C10, a ninth capacitor C9 and a seventh capacitor C7. The specific connection relationship can be referred to Figure 6 .

[0067] In some embodiments, as Figure 7 and Figure 8 As shown, each pin configuration unit 4 includes a configuration matrix unit 41 and a matrix control unit 42. Figure 7 As shown, the configuration matrix unit 41 includes several relays; the first end of the excitation coil of each relay is connected to the matrix control unit 42, and the second end of the excitation coil of each relay is connected to the second DC voltage to control whether each relay is excited according to the configuration signal; the common contact of the relay is used to connect each pin one by one, the normally closed contact of the relay is connected to the test current input terminal of the current sampling unit 2, and the normally open contact of the relay is connected to the test voltage input terminal of the voltage sampling unit 1, and then the conduction relationship between the corresponding pin and the voltage sampling unit 1 and the current sampling unit 2 is controlled according to whether the relay is excited.

[0068] In some embodiments, the configuration signal output by the main control unit 3 includes several address signals and control signals.

[0069] In some embodiments, as Figure 8 As shown, each matrix control unit 42 includes a number of D flip-flops and driver transistors corresponding to the number of relays, and a pull-up unit.

[0070] The clock input terminals of each D flip-flop are connected in parallel and serve as the address input terminals of the pin configuration unit 4 for receiving an address signal so that the main control unit 3 selects the control matrix control unit 42, and the input terminals of each D flip-flop serve as the control signal input terminals of the pin configuration unit 4 to receive the control signal so as to control the output signal of the D flip-flop; the output terminals of each D flip-flop are connected one-to-one with the control terminals of each driver tube, and the control terminals of each driver tube are also connected to the first DC voltage via the pull-up unit, and the output terminals of each driver tube are connected one-to-one with the output terminals of the excitation coils of each relay, and the output terminals of each driver tube are grounded, and the input terminals of the excitation coils of each relay are connected to the second DC voltage, thereby controlling whether the corresponding relay is excited according to the output signal of the D flip-flop.

[0071] Specifically, such as Figure 8 As shown, the D flip-flops can be provided by a D flip-flop array IC1. The model of D flip-flop array IC1 can be MM74HC374MTC, which integrates 8 D flip-flops. Pins 3, 4, 7, 8, 13, 14, 17, and 18 of D flip-flops correspond to the input terminals of each D flip-flop, pins 2, 5, 6, 9, 12, 15, 16, and 19 of D flip-flops correspond to the output terminals of each D flip-flop, and pin 11 corresponds to the address input terminal of pin configuration unit 4. The driver transistors can be provided by a Darlington transistor array IC2. The model of Darlington transistor array IC2 can be ULN2803A, which integrates 8 driver transistors. Pins 1 to 8 of D flip-flops correspond to the control terminals of each driver transistor, pins 11 to 18 of D flip-flops correspond to the input terminals of each driver transistor, and pin 9 of D flip-flops corresponds to the output terminal of each driver transistor. It is understood that the array of D flip-flops and driver transistors in the matrix control unit 42 can also be constructed using a single driver transistor or a combination of a driver transistor array and a single driver transistor to achieve the same function. For example, when each pin configuration unit 4 includes 10 relays, the required driver transistors can be implemented by adding two more driver transistors to the Darlington transistor array IC2, or by using 10 driver transistors. The pull-up unit can be a resistor array, wherein the first end of each resistor in the resistor array is simultaneously connected to the first DC voltage, and the second end of each resistor in the resistor array is respectively connected to the control terminal of each driver transistor in a one-to-one correspondence.

[0072] refer to Figure 7 and Figure 8The working principle of the pin configuration unit 4 is as follows: take the pins connected to relay K1, relay K3 and relay K9 as the pins to be tested as an example: first, the main control unit 3 sends a first configuration signal, which sets the 3rd and 7th pins in the D flip-flop array IC1 to a high level, and the control terminals of the remaining D flip-flops to a low level, and causes the address signal P1 connected to the address input terminal of the D flip-flop array IC1 to generate a rising edge signal. At this time, the 1st and 3rd pins in the control terminal of the Darlington transistor array IC2 are converted to a high level, and the driving transistors corresponding to the 1st and 3rd pins are turned on, so that relay K1 and relay K3 are energized, and then the pins corresponding to relay K1 and relay K3 are simultaneously connected to the voltage sampling unit 1. Based on the latching characteristics of the D flip-flop, the output of the D flip-flop array IC1 will be maintained before the next rising edge arrives, that is, relay K1 and relay K3 remain turned on;

[0073] Then the main control unit 3 sends a second configuration signal, which sets the third pin of the D flip-flop array IC3 to a high level and the other control terminals of the D flip-flop to a low level. At this time, the address signal P2 generates a rising edge signal, which converts the first pin of the Darlington transistor array IC4 to a high level, and the driving tube corresponding to the control terminal is turned on, so that the relay K9 is excited, and the pin corresponding to the relay K9 is also connected to the voltage sampling unit 1. At this time, the definition of the pin to be tested and other pins has been completed. If the insulation resistance of these pins is tested at this time, the main control unit 3 will control the test power supply to output a high-voltage constant voltage signal, and then use the voltage sampling unit 1, the current sampling unit 2 and the analog-to-digital conversion unit to collect the input voltage and input current of this test, and then calculate the insulation resistance of these pins to be tested according to formulas (1) and (2).

[0074] In some embodiments, the pin electrical performance test circuit includes eight pin configuration units 4, wherein each pin configuration unit 4 includes eight D flip-flops and eight drivers. Correspondingly, the configuration signal includes eight address signals and control signals.

[0075] In some embodiments, as Figure 9 As shown, the main control unit 3 includes a main control chip U1, a first crystal oscillator X1, a first capacitor C1, a second capacitor C2, a sixteenth resistor R16, a third transistor Q3, a first diode D1 and a buzzer BUZZER1. The main control chip U1 may be a DSPIC30F6014.

[0076] The DC power supply terminal and the analog power supply terminal of the main control chip U1 are connected to the DC voltage, the power configuration instruction output terminal of the main control chip U1 (corresponding to the 15th pin) is connected to the first end of the eleventh resistor R11, the current sampling configuration signal output terminal of the main control chip U1 (corresponding to the 56th pin) is connected to the second end of the fifth resistor R5, the first clock signal input terminal (corresponding to the 49th pin) and the second clock signal input terminal (corresponding to the 50th pin) of the main control chip U1 are connected in parallel with the first crystal oscillator X1, the first end of the first crystal oscillator X1 is connected to the ground via the first capacitor C1, the second end of the first crystal oscillator X1 is connected to the ground via the second capacitor C2, and the communication clock of the main control chip U1 is connected to the ground. The output terminal (corresponding to pin 18), the communication data input terminal (corresponding to pin 16) and the communication data output terminal (corresponding to pin 17) are connected to the communication clock input terminal, the communication data output terminal and the communication data input terminal of the analog-to-digital conversion chip U2 in sequence. The alarm control terminal (corresponding to pin 55) in the main control chip U1 is connected to the base of the third transistor Q3 via the sixteenth resistor R16. The collector of the third transistor Q3 is connected to the anode of the first diode D1 and the cathode of the buzzer BUZZER1. The cathode of the first diode D1 is connected to the positive electrode of the buzzer BUZZER1 and the first DC voltage. The emitter of the third transistor Q3 is grounded. In addition, the main control chip U1 includes several configuration signal output terminals (including pins 58, 61, 62, 63, 66, 67, 68 and 69) and address signal output terminals (including pins 75, 74, 47, 46, 6, 7, 8 and 10). Each configuration signal output terminal is connected to the pin configuration unit 4 to send configuration signals. The connection relationship of each port of the main control chip U1 can be referred to Figures 3 to 9 .

[0077] In some embodiments, the plug electrical performance test circuit further includes a communication unit. The communication unit is connected to the main control unit 3 and is configured to obtain test items output by the host computer and transmit the test data calculated by the main control unit 3 to the host computer. The host computer can be a terminal device such as a computer or mobile phone, allowing staff to set test items and input pre-stored plug information.

[0078] In some embodiments, the communication unit may be a Bluetooth module, and its model may be DX-BT07-E.

[0079] refer to Figure 10 The present invention also provides a method for testing the electrical performance of a pin, including: step S10, step S20 and step S30.

[0080] S10. Set at least one pin configuration unit.

[0081] S20. Generate a configuration signal according to the test item, and control the pin configuration unit through the configuration signal to connect the pin to be tested to the voltage sampling unit and other pins to the current sampling unit, so as to collect the input voltage of the pin to be tested and the input current of other pins.

[0082] S30. Calculate the insulation resistance or DC resistance of the pin to be tested according to the input voltage and input current.

[0083] In some embodiments, the configuration signal includes several address signals and control signals; the pin configuration unit in S10 includes a configuration matrix unit and a matrix control unit; correspondingly, in S20, it includes: enabling the matrix control unit according to the address signal, and the matrix control unit controls the matrix unit according to the control signal to connect the pin to be tested to the voltage sampling unit and other pins to the current sampling unit.

[0084] In some embodiments, step S30 includes: performing analog-to-digital conversion on the input voltage and input current, and calculating the insulation resistance or DC resistance of the pin to be tested based on the converted input voltage and input current.

[0085] It can be understood that the implementation of the present invention can realize automatic testing of the insulation resistance and DC resistance of each pin of the plug, greatly reducing the number of tests and time; it can also identify the conductivity between the pins in advance based on the pre-stored information of the plug, and skip the pins that are originally conductive or have a small DC resistance during testing, thereby avoiding meaningless insulation resistance testing between conductive pins; and when performing the insulation resistance test, when it is identified that the insulation resistance of the pin to be tested is significantly lower than the insulation resistance standard value, it automatically switches to the output channel of the test power supply to perform DC resistance measurement; further, the present invention, in conjunction with a conversion connector, can perform insulation resistance testing and DC resistance testing on the pins of any type of plug, and has the advantage of strong versatility.

[0086] It is understandable that the above embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, all of which fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A pin electrical performance test circuit, characterized in that: include: Voltage sampling unit, used to collect the input voltage of the pin to be tested; Current sampling unit, used to collect input current of other pins; At least one pin configuration unit, configured to connect the pin to be tested to the voltage sampling unit and connect other pins to the current sampling unit according to a configuration signal, so as to obtain the input voltage and input current; A main control unit, configured to output the configuration signal according to the test item, and calculate the insulation resistance or DC resistance of the pin to be tested according to the input voltage and input current; The voltage sampling unit includes a second relay, a ninth resistor, a twelfth resistor, and a tenth resistor; the first end of the excitation coil of the second relay is connected to the first DC voltage, the second end of the excitation coil of the second relay is connected to the main control unit, the second common contact of the second relay is connected to the pin configuration unit as a test voltage input end of the voltage sampling unit, the second normally closed contact of the second relay is connected to the low voltage constant voltage signal, the second normally open contact of the second relay is connected to the high voltage constant voltage signal via the twelfth resistor, the first common contact of the second relay is connected to the main control unit as a voltage sampling signal output end, the first normally closed contact of the second relay is connected to the pin configuration unit as a first voltage sampling end, the first normally open contact of the second relay is connected to the first voltage sampling end via the ninth resistor as a second voltage sampling end, and the second voltage sampling end is also connected to ground via the tenth resistor; The current sampling unit includes a first relay, a third resistor, and a fourth resistor; the first end of the excitation coil of the first relay is connected to a first DC voltage, the second end of the excitation coil of the first relay is connected to the main control unit, the first common contact of the first relay serves as a test current input end of the current sampling unit, connected to the pin configuration unit and the second normally open contact of the first relay, the test current input end is also connected to the first end of the fourth resistor via the third resistor, the first end of the fourth resistor is also connected to the first normally closed contact and the second normally closed contact of the first relay, the second end of the fourth resistor is grounded, and the second common contact of the first relay is connected to the main control unit.

2. The pin electrical performance test circuit according to claim 1, characterized in that: The pin electrical performance test circuit also includes a test power supply; the main control unit also outputs a power configuration instruction according to the test item; the voltage sampling unit sets its voltage sampling end and the output channel of the test power supply according to the power configuration instruction to obtain the high-voltage constant-voltage signal required for the insulation resistance test or the low-voltage constant-voltage signal required for the DC resistance test.

3. The pin electrical performance test circuit according to claim 2, characterized in that: The voltage sampling unit further includes a fourth diode, a second switch tube, an eleventh resistor, a sixth voltage regulator tube, and a sixth resistor; One end of the excitation coil of the second relay is connected to the cathode of the fourth diode, a second end of the excitation coil of the second relay is connected to the anode of the fourth diode and the input end of the second switching tube, the output end of the second switching tube is grounded, the control end of the second switching tube is connected to the second end of the eleventh resistor, and the first end of the eleventh resistor is connected to the main control unit as a power configuration instruction input end; The first common contact of the second relay is connected to the cathode of the sixth voltage-stabilizing tube, the anode of the sixth voltage-stabilizing tube is grounded, and the first normally closed contact of the second relay is connected to the pin configuration unit via the sixth resistor.

4. The pin electrical performance test circuit according to claim 3, characterized in that: The pin electrical performance test circuit further comprises a constant current unit (5); the constant current unit (5) is connected between the voltage sampling unit and the pin configuration unit.

5. The pin electrical performance test circuit according to claim 1, characterized in that: The current sampling unit further includes a first switch tube, a fifth resistor, a seventeenth resistor and a fifth voltage regulator tube; The second end of the excitation coil of the first relay is connected to the input end of the first switching tube, the output end of the first switching tube is grounded, the control end of the first switching tube is connected to the first end of the fifth resistor, and the second end of the fifth resistor is connected to the main control unit as the current sampling configuration signal input end; The second common contact of the first relay is connected to the first end of the seventeenth resistor, the second end of the seventeenth resistor is connected to the main control unit as the current sampling signal output end, the second end of the seventeenth resistor is also connected to the cathode of the fifth voltage regulator tube, and the anode of the fifth voltage regulator tube is grounded.

6. The pin electrical performance test circuit according to claim 1, characterized in that: The pin electrical performance test circuit further includes an analog-to-digital conversion unit, which includes an analog-to-digital conversion chip, a third voltage regulator tube, a fifteenth resistor, a second crystal oscillator, a fifth capacitor, a sixth capacitor, a fourteenth resistor and an eighth capacitor; The reference voltage input terminal of the analog-to-digital conversion chip is connected to the cathode of the third voltage-stabilizing diode, and the anode of the third voltage-stabilizing diode is grounded. The reference voltage input terminal of the analog-to-digital conversion chip is also connected to the first DC voltage via the fifteenth resistor. The eighth capacitor is connected in parallel with the third voltage-stabilizing diode. The first and second clock signal input terminals of the analog-to-digital conversion chip are connected in parallel with the second crystal oscillator. The first end of the second crystal oscillator is connected to the ground via the sixth capacitor, and the second end of the second crystal oscillator is connected to the ground via the fifth capacitor. The first analog channel input terminal of the analog-to-digital conversion chip is connected to the current sampling signal output terminal of the current sampling unit, the second analog channel input terminal of the analog-to-digital conversion chip is connected to the voltage sampling signal output terminal of the voltage sampling unit, the first and second analog channel ground terminals of the analog-to-digital conversion chip are grounded, the communication clock input terminal, the communication output terminal, and the communication input terminal of the analog-to-digital conversion chip are connected to the main control unit, and the reset terminal of the analog-to-digital conversion chip is connected to the first DC voltage via the fourteenth resistor.

7. The pin electrical performance test circuit according to any one of claims 1 to 6, characterized in that: Each of the pin configuration units includes a configuration matrix unit (41) and a matrix control unit (42); The configuration matrix unit (41) includes a plurality of relays; the first end of the excitation coil of each relay is connected to the matrix control unit (42), and the second end of the excitation coil of each relay is connected to a second DC voltage to control whether each relay is excited according to the configuration signal; the common contact of the relay is used to connect each pin in a one-to-one correspondence, the normally closed contact of the relay is connected to the test current input end of the current sampling unit, and the normally open contact of the relay is connected to the test voltage input end of the voltage sampling unit, thereby controlling the conduction relationship between the corresponding pin and the voltage sampling unit and the current sampling unit according to whether the relay is excited.

8. The pin electrical performance test circuit according to claim 7, characterized in that: The configuration signal includes a number of address signals and control signals; The matrix control unit (42) includes a plurality of D flip-flops and driving tubes corresponding to the number of the relays, and a pull-up unit; the clock input terminals of the D flip-flops are connected in parallel and serve as the address input terminals of the pin configuration unit for receiving an address signal so that the main control unit selects to control the matrix control unit (42), and the input terminals of the D flip-flops serve as the control signal input terminals of the pin configuration unit to receive the control signal so as to control the output signal of the D flip-flops; The output end of each D trigger is connected to the control end of each driving tube in a one-to-one correspondence, and the control end of each driving tube is also connected to the first DC voltage via the pull-up unit. The output end of each driving tube is connected to the output end of the excitation coil of each relay in a one-to-one correspondence, and the output end of each driving tube is grounded. The input end of the excitation coil of each relay is connected to the second DC voltage, and then the corresponding relay is controlled to be excited according to the output signal of the D trigger.

9. The pin electrical performance test circuit according to claim 8, characterized in that: The pin electrical performance test circuit also includes: The communication unit is connected to the main control unit and is used to obtain the test items output by the host computer and send the test data calculated by the main control unit to the host computer.

10. A method for testing the electrical performance of a pin, characterized in that: The following steps are involved: S10, setting at least one pin configuration unit; S20. Generate a configuration signal according to the test item, and control the pin configuration unit through the configuration signal to connect the pin to be tested to the voltage sampling unit and other pins to the current sampling unit, so as to collect the input voltage of the pin to be tested and the input current of other pins; S30, calculating the insulation resistance or DC resistance of the pin to be tested according to the input voltage and input current; The voltage sampling unit includes a second relay, a ninth resistor, a twelfth resistor, and a tenth resistor; the first end of the excitation coil of the second relay is connected to the first DC voltage, the second end of the excitation coil of the second relay is connected to the main control unit, the second common contact of the second relay is connected to the pin configuration unit as a test voltage input end of the voltage sampling unit, the second normally closed contact of the second relay is connected to the low voltage constant voltage signal, the second normally open contact of the second relay is connected to the high voltage constant voltage signal via the twelfth resistor, the first common contact of the second relay is connected to the main control unit as a voltage sampling signal output end, the first normally closed contact of the second relay is connected to the pin configuration unit as a first voltage sampling end, the first normally open contact of the second relay is connected to the first voltage sampling end via the ninth resistor as a second voltage sampling end, and the second voltage sampling end is also connected to ground via the tenth resistor; The current sampling unit includes a first relay, a third resistor, and a fourth resistor; the first end of the excitation coil of the first relay is connected to a first DC voltage, the second end of the excitation coil of the first relay is connected to the main control unit, the first common contact of the first relay serves as a test current input end of the current sampling unit, connected to the pin configuration unit and the second normally open contact of the first relay, the test current input end is also connected to the first end of the fourth resistor via the third resistor, the first end of the fourth resistor is also connected to the first normally closed contact and the second normally closed contact of the first relay, the second end of the fourth resistor is grounded, and the second common contact of the first relay is connected to the main control unit.

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