Short circuit and resistance detection device and detection method

Abstract

The short circuit and resistance detection device comprises a circuit board assembly, the circuit board assembly is electrically connected with a rectangular connector, the circuit board assembly comprises an MCU, and the MCU is electrically connected with a power supply unit, a switch unit and a detection unit; the switch unit comprises a short circuit detection switch unit, a short circuit detection interruption switch unit, a resistance value detection switch unit and a resistance value detection interruption switch unit; the detection unit comprises a short circuit detection unit and a resistance value detection unit; the MCU comprises a plurality of PA pins and a plurality of PC pins, the PA pins comprise a PA0 pin and a PAn pin, and the PC pins comprise a PCi pin; n = 1... n, and i = 0... i. According to the invention, whether any signal is short-circuited to other multipath signals can be simultaneously detected, resistance values of multiple products can be detected, personnel configuration is reduced, product detection accuracy is improved, and detection time is shortened. The invention further discloses a detection method of the short circuit and resistance value detection device.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of circuit testing, and relates to a short circuit and resistance value detection device, and also relates to a detection method of the short circuit and resistance value detection device. BACKGROUND

[0002] At present, the main tool for detecting short circuit between signals on the market is a multimeter. The multimeter can meet the detection requirements for detecting whether two signals are short-circuited. However, the multimeter cannot meet the requirements for detecting whether any two of multiple signals are short-circuited at the same time. When input and output resistance values of multiple signals are detected, the resistance values are detected by manually clicking the signal input and output ends with a multimeter pen, which is easy to cause errors and affects the efficiency and accuracy of the detection results. SUMMARY

[0003] The present application provides a short circuit and resistance value detection device, which solves the problem of once detecting whether two signals are short-circuited and the problem of easy to cause poor connection when manually clicking the signals for short circuit detection and resistance value detection.

[0004] Another object of the present application is to provide a detection method of the short circuit and resistance value detection device.

[0005] The technical scheme adopted by the present application is that the short circuit and resistance value detection device comprises a circuit board assembly, the circuit board assembly is electrically connected with a rectangular connector, the circuit board assembly comprises a microcontroller (MCU), the MCU is electrically connected with a power supply unit, a switch unit and a detection unit respectively; the switch unit comprises a short circuit detection switch unit, a short circuit detection interrupt switch unit, a resistance value detection switch unit and a resistance value detection interrupt switch unit; the detection unit comprises a short circuit detection unit and a resistance value detection unit; the MCU comprises a plurality of PA pins and a plurality of PC pins, the PA pins comprise a PA0 pin and a PAn pin, and the PC pins comprise a PCi pin; n=1……n, i=0……i.

[0006] The present application also has the following characteristics: The rectangular connector comprises two groups, including a first rectangular connector and a second rectangular connector, the first rectangular connector comprises an X1 connector and a J1 connector, and the second rectangular connector comprises an X2 connector and a J2 connector; the J1 connector comprises a plurality of input ends Ai, and the J2 connector comprises a plurality of output ends Ai_O. The short circuit detection switch unit comprises a button switch SW2, a normally open end T1 of the button switch SW2 is electrically connected with a resistor R2, the other end of the resistor R2 is electrically connected with a power supply VCC3.3, a common end S1 of the button switch SW2 is electrically connected with a capacitor C7, a pin 58 of the MCU and a common end S1 of a button switch SW1 respectively; the normally closed end T2 of the button switch SW2 and the other end of the capacitor C7 are both grounded. The short circuit detection interrupt switch unit includes a button switch SW3, the normally open end T1 of the button switch SW3 is electrically connected with a resistor R5, the other end of the resistor R5 is electrically connected with a power supply VCC3.3, the common end S1 of the button switch SW3 is electrically connected with a capacitor C9, a pin 59 of an MCU and the common end S1 of a button switch SW2 respectively; the normally closed end T2 of the button switch SW3 and the other end of the capacitor C9 are grounded; The resistance detection switch unit includes a button switch SW4, the normally open end T1 of the button switch SW4 is electrically connected with a resistor R10, the other end of the resistor R10 is electrically connected with a power supply VCC3.3, the common end S1 of the button switch SW4 is electrically connected with a capacitor C12, a pin 61 of an MCU and the common end S1 of the button switch SW3 respectively; the normally closed end of the button switch SW4 and the other end of the capacitor C12 are grounded; The resistance detection interrupt switch unit includes a button switch SW5, the normally open end T1 of the button switch SW5 is electrically connected with a resistor R11, the other end of the resistor R11 is electrically connected with a power supply VCC3.3, the common end S1 of the button switch SW5 is electrically connected with a capacitor C22, a pin 62 of an MCU and the common end S1 of the button switch SW4 respectively; the normally closed end T2 of the button switch SW5 and the other end of the capacitor C22 are grounded.

[0007] The power supply unit includes a button switch SW1, the normally open end T1 of the button switch SW1 is electrically connected with a pin 1 of a P1 interface, the common end S1 of the button switch SW1 is electrically connected with a transient voltage suppressor D1 and a fuse F1 respectively; the other end of the fuse F1 is electrically connected with a capacitor C1, a capacitor C2 and a Vin pin of a voltage stabilizing chip U1 respectively; a Vout pin of the voltage stabilizing chip U1 is electrically connected with a capacitor C3, a capacitor C4 and a Vin pin of a voltage stabilizing chip U2 respectively; a Vout pin of the voltage stabilizing chip U2 is electrically connected with a capacitor C5, a capacitor C6 respectively; a power supply VCC5 is electrically connected between the capacitor C3 and the capacitor C4, a power supply VCC3.3 is electrically connected between the capacitor C5 and the capacitor C6; The pin 2 and the pin 3 of the P1, the normally closed end T2 of the button switch SW1, the capacitor C1, the capacitor C2, a GND pin of the voltage stabilizing chip U1, the capacitor C3, the capacitor C4, a GND pin of the voltage stabilizing chip U2, the capacitor C5, the capacitor C6 are grounded together; The power supply VCC3.3 is electrically connected with a resistor R1 and the anode of a light emitting diode LED1 in sequence, the cathode of the light emitting diode LED1 is grounded.

[0008] The short circuit detection unit comprises a PA0 short circuit detection unit and a PAn short circuit detection unit. The PA0 short circuit detection unit comprises a field effect transistor Q1, the collector S of the field effect transistor Q1 is electrically connected with a resistor R13, a capacitor C23 and a power supply VCC5 respectively, the gate G is electrically connected with a resistor R14 and the collector 3 of a transistor Q2 in sequence, the drain D is electrically connected with a resistor R12 and an A0 input end in the J1 connector in sequence; the other end of the resistor R13 and the other end of the capacitor C23 are commonly electrically connected between the gate G and the resistor R14; the base 1 of the transistor Q2 is electrically connected with a resistor R15 and a resistor R16 respectively, the other end of the resistor R15 is electrically connected with an emitting diode LED a and the pin PA0 of the MCU, the other end of the resistor R16 is commonly grounded with the emitter 2; The PAn short circuit detection unit comprises a field effect transistor Q a , the collector S of the field effect transistor Q a is electrically connected with a resistor R a , a capacitor C a and a power supply VCC5 respectively, the gate G is electrically connected with a resistor R b and the collector 3 of a transistor Q b in sequence, the drain D is electrically connected with a resistor R e and an An output end in sequence, the An output end is electrically connected with a corresponding Ai input end in the J1 connector, the An output end is also electrically connected with the anode of an emitting diode LEDn+1, the cathode of the emitting diode LEDn+1 is grounded; the other end of the resistor R a and the other end of the capacitor C a are commonly electrically connected between the gate G and the resistor R b ; the base 1 of the transistor Q b is electrically connected with a resistor R c and a resistor R d respectively, the other end of the resistor R c is electrically connected with a pin PAn on the MCU, the other end of the resistor R d is commonly grounded with the emitter 2.

[0009] The resistance value detection unit comprises an Ai input end unit and an Ai_O output end unit. The Ai input end unit comprises an emitting diode LED b , the anode of the emitting diode LED b is electrically connected with a PCi pin on the MCU, the cathode is electrically connected with a resistor R f , the resistor R f is electrically connected with a resistor R g and the base b of a transistor Q c respectively, the other end of the resistor R g is commonly grounded with the emitter e of the transistor Q c ; the collector c of the transistor Q c is electrically connected with a diode D aThe positive terminal and relay JK a Contact 1, diode D a The negative terminal and relay JK a Contact 2 is connected to power supply VCC5; Relay JK a Contact 4 is electrically connected to the corresponding Ai input terminal of connector J1, and contact 3 is electrically connected to the positive terminal of the ohmmeter. The Ai_O output unit includes a resistor R. h resistance R h One end is electrically connected to the PCi pin on the MCU, and the resistor R h The other end is electrically connected to resistor R. j and transistor Q d The base b, resistor R j The other end is connected to transistor Q. d The emitter (e) of the transistor is grounded; transistor Q d The collectors c are electrically connected to diode D respectively. b The positive terminal and relay JK b Contact 1, diode D b The negative terminal and relay JK b Contact 2 is connected to power supply VCC5; Relay JK b Contact 4 is electrically connected to the corresponding Ai_O output terminal of the J2 connector, and contact 3 is electrically connected to the negative terminal of the ohmmeter.

[0010] Pin 5 of the MCU is electrically connected to capacitor C8 and the input terminal of dual-electrode crystal oscillator Y1 respectively. The output terminal of dual-electrode crystal oscillator Y1 is connected to capacitor C10 and resistor R7 respectively. The other end of resistor R7 is connected to pin 6 of the MCU. The connection point of capacitor C8 and capacitor C10 is grounded together. Pin 43 of the MCU is electrically connected to pin 3 of P2, pin 42 of the MCU is electrically connected to pin 2 of P2, and pin 1 of P2 is grounded; pin 60 of the MCU is electrically connected to resistor R8 and power supply VCC3.3, with the other end of resistor R8 grounded; pin 7 of the MCU is electrically connected to the reset signal node RESET, which is electrically connected to resistor R9 and capacitor C11, with the other end of R9 connected to power supply VCC3.3 and the other end of capacitor C11 grounded; pin 13 of the MCU is electrically connected to ferrite bead FB1 and capacitors C15 and C16, with the other end of ferrite bead FB1 connected to power supply VCC3.3, and the other ends of capacitors C15 and C16 grounded; pin 28 of the MCU is electrically connected to pin BOOT1, resistor R4, and power supply VCC3.3, with the other end of resistor R4 grounded; MCU Pin 31 of the MCU is electrically connected to capacitor C14, with the other end of capacitor C14 grounded; pin 47 of the MCU is electrically connected to capacitor C13, with the other end of capacitor C13 grounded; pins 63, 18, and 12 of the MCU are all grounded; pins 1, 32, 48, 64, and 19 of the MCU are all electrically connected to power supply VCC3.3; pins 49 and 46 of the MCU are electrically connected to download port P3; pin 1 of download port P3 is electrically connected to diode D7 and power supply VCC3.3, with the other end of diode D7 grounded; pin 2 of download port P3 is grounded; pin 3 of download port P3 is electrically connected to diode D6 and pin 49 of the MCU, with the other end of diode D6 grounded; pin 4 of download port P3 is electrically connected to diode D5 and pin 46 of the MCU, with the other end of diode D5 grounded.

[0011] The power supply VCC3.3 is also electrically connected to a filter circuit, which includes several capacitors. One end of capacitors C17, C18, C19, C20, and C21 is electrically connected to the power supply VCC3.3, and the other end is grounded together.

[0012] Capacitor C4 is electrically connected to diode D2 between it and the Vin pin of voltage regulator chip U2. Capacitor C6 is also electrically connected to diode D3. Both diodes D2 and D3 are grounded. Pin 60 of the MCU is electrically connected to resistors R6 and R8 respectively. The other end of resistor R6 is electrically connected to power supply VCC3.3. Pin 28 of the MCU is electrically connected to pin BOOT1, resistor R3 and resistor R4 respectively. The other end of resistor R3 is electrically connected to power supply VCC3.3.

[0013] Another technical solution adopted in this invention is a detection method for a short circuit and resistance detection device, which includes a short circuit detection method and a resistance detection method.

[0014] Another feature of the technical solution of this invention is that: The short-circuit detection method is implemented according to the following steps: Step 1: Connect the signal input terminal of the device under test (DUT) to connector X1 and the signal output terminal of the DUT to connector X2; connect connector X1 to connector J1 and connector X2 to connector J2. Step 2: Close the power switch SW1; Step 3, short circuit detection; When the short-circuit detection switch SW2 is closed, PA0, PA1...PAn output high levels in sequence; When PA0 outputs a high level, the A0 signal sequentially performs short-circuit detection on the A1 signal...An signal, and ground signal; when the A0 signal does not short-circuit any other signal, the LED... a When the LED is lit, PA1 outputs a high level; when the A0 signal is short-circuited to the An signal, the LED... a Only LEDn+1 is lit, while the other LEDs are not lit. When PAm outputs a high level, the Am signal sequentially performs short-circuit detection on the Am+1 signal...An signal, and ground signal; when the Am signal does not short-circuit other signals, LEDm+1 lights up, and then it is PAm+1's turn to output a high level; if the Am signal short-circuits the An signal, LEDm+1 and LEDn+1 light up, while other LEDs do not light up; n is greater than m+1; Step 4, short circuit detection interrupted; When a short circuit occurs between two signals, close SW3 switch to interrupt the short circuit detection, record the fault, and then open SW3 switch to continue the detection. The resistance detection method is implemented according to the following steps: Step 1: Connect the signal input terminal of the device under test (DUT) to connector X1, and connect the signal output terminal of the DUT to connector X2; connect connector X1 to connector J1, and connector X2 to connector J2; connect the positive terminal of the ohmmeter to the i relays JK in the Ai input unit. a Contact 3 connects the negative terminal of the ohmmeter to the i-th relay JK in the Ai_O output terminal. b Contact point 3; Step 2: Close the power switch SW1; Step 3, resistance detection; When the resistance detection switch SW4 is closed, the MCU's PC0 to PCi output high levels in sequence; Connect signals A0, A0_O, ..., Ai, Ai_O sequentially between the positive and negative terminals of the ohmmeter. When the i-th group of signals is detected, the corresponding LED will... b Light it up; read the resistance value of group i using an ohmmeter; Step 4, resistance interruption detection; When any signal resistance value detection abnormal situation occurs, the SW5 switch is closed, the resistance value detection is interrupted, the fault is recorded, and the SW5 switch is opened again to continue the resistance value detection.

[0015] The beneficial effects of the present application are: (1) The short circuit and resistance value detection device provided by the present application can detect whether any signal is short-circuited to other multiple signals, when two signals are short-circuited, the two signals are lit, and the tester can directly determine which two signals are short-circuited, realize the resistance value detection between the input and output of different signals, and the detection data is stable and accurate, avoiding uncontrollable factors of manual detection.

[0016] (2) The short circuit and resistance value detection device provided by the present application only needs to connect the product input and output interfaces to the input and output interfaces of the detection device through a cable, and then the detection can be performed. When the product input and output interfaces are designed not on the same surface, multiple people do not need to use a multimeter for detection operation, and the number of personnel configuration can be reduced.

[0017] (3) The short circuit and resistance value detection device provided by the present application can greatly shorten the detection time, and the original manual detection of 17 signals for short circuit and resistance value and recording data needs 2 people for 20 minutes, and the detection device only needs 1 person for 3.5 minutes, and the detection efficiency is improved by about 11 times. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is the MCU diagram of the present application; Figure 2 is the filter circuit diagram of the present application; Figure 3 is the short circuit detection switch unit circuit diagram of the present application; Figure 4 is the short circuit detection interrupt switch unit circuit diagram of the present application; Figure 5 is the resistance value detection switch unit circuit diagram of the present application; Figure 6 is the resistance value detection interrupt switch unit circuit diagram of the present application; Figure 7 is the PA0 short circuit detection unit circuit diagram of the present application; Figure 8 is the PAn short circuit detection unit circuit diagram of the present application; Figure 9 is the short circuit detection unit An output end and light emitting diode connection circuit diagram of the present application; Figure 10 is the Ai input end unit circuit diagram of the present application; Figure 11 is the Ai_O output end unit circuit diagram of the present application; Figure 12The measured piece signal input to the output resistance detection principle block diagram of the application; Figure 13 The power supply unit circuit diagram of the application; Figure 14 The light emitting diode connection circuit diagram in the power supply unit of the application; Figure 15 The front view of the shell of the application; Figure 16 The J1 connector plane schematic diagram of the application; Figure 17 The J2 connector plane schematic diagram of the application; Figure 18 The short circuit detection and resistance detection method flow chart of the application. DETAILED DESCRIPTION

[0019] The following will be described in detail in combination with specific embodiments.

[0020] The short circuit and resistance detection device comprises a circuit board assembly, a rectangular connector electrically connected to the circuit board assembly, the circuit board assembly comprising an MCU, the MCU being electrically connected to a power supply unit, a switch unit and a detection unit respectively; the switch unit comprising a short circuit detection switch unit, a short circuit detection interrupt switch unit, a resistance detection switch unit and a resistance detection interrupt switch unit; the detection unit comprising a short circuit detection unit and a resistance detection unit; the MCU comprising a plurality of PA pins and a plurality of PC pins, the PA pins comprising a PA0 pin and a PAn pin, and the PC pins comprising a PCi pin; n = 1 …… n, i = 0 …… i.

[0021] The rectangular connector comprises two groups, including a first rectangular connector and a second rectangular connector, the first rectangular connector comprising an X1 connector and a J1 connector, and the second rectangular connector comprising an X2 connector and a J2 connector; the J1 connector comprising a plurality of input ends Ai, and the J2 connector comprising a plurality of output ends Ai_O; the X1 connector being connected to a measured piece signal input end, and the X2 connector being connected to a measured piece signal output end; the X1 connector and the J1 connector being connected, and the X2 connector and the J2 connector being connected, so that all signals of the measured piece are connected to the short circuit and resistance detection device, and a detection path between the measured piece and the short circuit and resistance detection device is completed.

[0022] As shown in Figure 1 , the MCU comprises a plurality of PA pins, PB pins and PC pins. The PA pins comprise a PA0 pin and a PAn pin, and the PC pins comprise a PCi pin. The PA pins of the MCU are connected to the short circuit detection circuit. When the number of PA pins is less than the number of short circuit detection circuits, the PB pins are used as backup ends of the PA pins, and the remaining short circuit detection circuits are connected to the PB pins.

[0023] AsFigure 1 In the embodiment, the total number of short-circuit detection circuit units is 16, the number of PA pins of the MCU is 12, and the remaining 4 short-circuit detection circuit units A12, A13, A14, and A15 correspond to the PB0, PB1, PB3, and PB4 pins of the MCU, respectively.

[0024] The pin 43 of the MCU is electrically connected to the pin 3 of P2, the pin 42 of the MCU is electrically connected to the pin 2 of P2, and the pin 1 of P2 is grounded.

[0025] The pin 5 of the MCU is electrically connected to the input end of the double-electrode crystal oscillator Y1 and the capacitor C8, the output end of the double-electrode crystal oscillator Y1 is connected to the capacitor C10 and the resistor R7, the other end of the resistor R7 is connected to the pin 6 of the MCU, and the connection points of the capacitor C8 and the capacitor C10 are grounded. In the embodiment, the capacitance of the capacitor C8 is 30 pF, the accuracy is 1%, the capacitance of the capacitor C10 is 20 pF, the accuracy is 1%, and the resistance of the resistor R7 is 200 ohms, the accuracy is 1%.

[0026] The pin 60 of the MCU is electrically connected to the resistor R6 and the resistor R8, the other end of the resistor R6 is electrically connected to the power supply VCC3.3, and the other end of the resistor R8 is grounded. In the embodiment, the resistance of the resistor R6 is 10 kΩ, the tolerance is 1%, the resistance of the resistor R8 is 10 kΩ, and the tolerance is 1%. The resistor R6 is not installed by default.

[0027] The pin 7 of the MCU is electrically connected to the reset signal node RESET, the reset signal node RESET is electrically connected to the resistor R9 and the capacitor C11, the other end of the resistor R9 is electrically connected to the power supply VCC3.3, and the other end of the capacitor C11 is grounded. In the embodiment, the resistance of the resistor R9 is 10 kΩ, the tolerance is 1%, the capacitance of the capacitor C11 is 100 nF, and the rated voltage is 50 volts.

[0028] The pin 13 of the MCU is electrically connected to the magnetic beads FB1 and the capacitors C15 and C16, the other end of the magnetic beads FB1 is electrically connected to the power supply VCC3.3, and the other ends of the capacitors C15 and C16 are commonly grounded. In the embodiment, the capacitance of the capacitor C15 is 1 uF, and the capacitance of the capacitor C16 is 100 nF.

[0029] 6. The pin 28 of the MCU is electrically connected to the pin BOOT1, the resistor R3, and the resistor R4, the other end of the resistor R3 is electrically connected to the power supply VCC3.3, and the other end of the resistor R4 is grounded. In the embodiment, the resistance of the resistor R3 is 10 kΩ, the tolerance is 1%, and the resistor R3 is not installed by default; the resistance of the resistor R4 is 10 kΩ, and the tolerance is 1%.

[0030] The pin 31 of the MCU is electrically connected to the capacitor C14, and the other end of the capacitor C14 is grounded. In the embodiment, the capacitance of the capacitor C14 is 2.2 µF, and the tolerance is 5%.

[0031] The pin 47 of the MCU is electrically connected with a capacitor C13, and the other end of the capacitor C13 is grounded. The capacitance of the capacitor C13 is 2.2 µF, and the tolerance is 5%.

[0032] The pin 63, the pin 18 and the pin 12 of the MCU are commonly grounded.

[0033] The pin 1, the pin 32, the pin 48, the pin 64 and the pin 19 of the MCU are commonly electrically connected with a power supply VCC3.3.

[0034] The pin 1 of the pin 3 of the MCU is electrically connected with a diode D7 and the power supply VCC3.3, and the other end of the diode D7 is grounded; the pin 2 of the pin 3 of the MCU is grounded; the pin 3 of the pin 3 of the MCU is electrically connected with a diode D6 and the pin 49 of the MCU, and the other end of the diode D6 is grounded; and the pin 4 of the pin 3 of the MCU is electrically connected with a diode D5 and the pin 46 of the MCU, and the other end of the diode D5 is grounded.

[0035] As shown in the figure, Figure 2 The power supply VCC3.3 is also electrically connected with a filter circuit, and the filter circuit includes a plurality of capacitors. The one end of a capacitor C17, a capacitor C18, a capacitor C19, a capacitor C20 and a capacitor C21 is electrically connected with the power supply VCC3.3, and the other end is commonly grounded. The main function of the capacitor is filtering, and the capacitor provides a power supply without electromagnetic clutter interference for the MCU. The capacitance of the capacitor C17, the capacitor C18, the capacitor C19, the capacitor C20 and the capacitor C21 can be selected as 100 nF, and the rated voltage is 50 volts.

[0036] As shown in the figure, Figure 3 The short circuit detection switch unit includes a button switch SW2. The normally open end T1 of the button switch SW2 is electrically connected with a resistor R2, and the other end of the resistor R2 is electrically connected with the power supply VCC3.3. The common end S1 of the button switch SW2 is electrically connected with a capacitor C7, the pin 58 of the MCU and the common end S1 of the button switch SW1. The normally closed end T2 of the button switch SW2 and the other end of the capacitor C7 are grounded. The resistance of the resistor R2 can be selected as 1000 ohms, and the capacitance of the capacitor C7 is 100 nF, and the rated voltage is 50 volts.

[0037] As shown in the figure, Figure 4 The short circuit detection interrupt switch unit includes a button switch SW3. The normally open end T1 of the button switch SW3 is electrically connected with a resistor R5, and the other end of the resistor R5 is electrically connected with the power supply VCC3.3. The common end S1 of the button switch SW3 is electrically connected with a capacitor C9, the pin 59 of the MCU and the common end S1 of the button switch SW2. The normally closed end T2 of the button switch SW3 and the other end of the capacitor C9 are grounded. The resistance of the resistor R5 can be selected as 1000 ohms, and the capacitance of the capacitor C9 is 100 nF, and the rated voltage is 50 volts.

[0038] As shown in Figure 5 , the resistance detection switch unit includes a button switch SW4, the normally open end T1 of the button switch SW4 is electrically connected with a resistor R10, the other end of the resistor R10 is electrically connected with a power supply VCC3.3, the common end S1 of the button switch SW4 is electrically connected with a capacitor C12, the pin 61 of the MCU and the common end S1 of the button switch SW3 respectively; the normally closed end of the button switch SW4 and the other end of the capacitor C12 are both grounded. Among them, the resistance value of the resistor R10 can be selected as 1000 ohms; the capacitance value of the capacitor C12 is 100 nF, and the rated voltage is 50 volts.

[0039] As shown in Figure 6 , the resistance detection interrupt switch unit includes a button switch SW5, the normally open end T1 of the button switch SW5 is electrically connected with a resistor R11, the other end of the resistor R11 is electrically connected with a power supply VCC3.3, the common end S1 of the button switch SW5 is electrically connected with a capacitor C22, the pin 62 of the MCU and the common end S1 of the button switch SW4 respectively; the normally closed end T2 of the button switch SW5 and the other end of the capacitor C22 are both grounded. Among them, the resistance value of the resistor R11 can be selected as 1000 ohms; the capacitance value of the capacitor C22 is 100 nF, and the rated voltage is 50 volts.

[0040] The short circuit detection unit includes a PA0 short circuit detection unit and a PAn short circuit detection unit.

[0041] As shown in Figure 7 , the PA0 short circuit detection unit includes a field effect tube Q1, the collector S of the field effect tube Q1 is electrically connected with a resistor R13, a capacitor C23 and a power supply VCC5 respectively, the gate G is sequentially electrically connected with a resistor R14 and the collector 3 of a triode Q2, the drain D is sequentially electrically connected with a resistor R12 and the A0 input end in the J1 connector. The other end of the resistor R13 and the other end of the capacitor C23 are commonly electrically connected between the gate G and the resistor R14. The base 1 of the triode Q2 is electrically connected with a resistor R15 and a resistor R16 respectively, the other end of the resistor R15 is sequentially electrically connected with a light emitting diode LED a and the pin PA0 of the MCU, the other end of the resistor R16 is commonly grounded with the emitter 2.

[0042] Among them, the resistance value of the resistor R12 can be selected as 680 ohms, and the tolerance is 1%; the resistance value of the resistor R13 is 100 kilo-ohms, and the tolerance is 1%; the resistance value of the resistor R14 is 1 kilo-ohms, and the tolerance is 1%; the resistance value of the resistor R15 is 680 ohms, and the tolerance is 1%; the resistance value of the resistor R16 is 47 kilo-ohms, and the tolerance is 1%; the capacitance value of the capacitor C23 is 100 nF, and the rated voltage is 50 volts.

[0043] As shown in Figure 8 , the PAn short circuit detection unit includes a field effect tube Q a , the collector S of the field effect tube Q aThe collector S of the transistor Q a is electrically connected with the resistor R a , the capacitor C b and the power supply VCC5 respectively, the gate G is electrically connected with the resistor R b and the collector 3 of the transistor Q e in turn, the drain D is electrically connected with the resistor R a and the An output terminal in turn, the An output terminal is electrically connected with the corresponding Ai input terminal of the J1 connector; the other end of the resistor R a and the other end of the capacitor C b are electrically connected together between the gate G and the resistor R b . The base 1 of the transistor Q c is electrically connected with the resistor R d and the resistor R c respectively, the other end of the resistor R d is electrically connected with the pin PAn on the MCU, and the other end of the resistor R c is electrically connected with the emitter 2 to ground. As shown in Figure 9 , the An output terminal is also electrically connected with the positive electrode of the light emitting diode LEDn+1, and the negative electrode of the light emitting diode LEDn+1 is grounded.

[0044] Among them, the resistance value of the resistor R c is 10 kilo-ohms, and the tolerance is 1%; the resistance value of the resistor R a is 100 kilo-ohms, and the tolerance is 1%; the resistance value of the resistor R b is 1 kilo-ohm, and the tolerance is 1%; the resistance value of the resistor R e is 680Ω, and the tolerance is 1%; the resistance value of the resistor R d is 47 kilo-ohms, and the tolerance is 1%; the capacitance value of the capacitor C a is 100nF, and the rated voltage is 50 volts.

[0045] The resistance value detection circuit unit includes the Ai input terminal unit and the Ai_O output terminal unit. As shown in Figure 10 , the Ai input terminal unit includes the light emitting diode LED b , the positive electrode of the light emitting diode LED b is electrically connected with the PCi pin on the MCU, the negative electrode is electrically connected with the resistor R f , the resistor R f is electrically connected with the resistor R g and the base b of the transistor Q c respectively, and the other end of the resistor R g is electrically connected with the emitter e of the transistor Q c to ground; the collector c of the transistor Q c is electrically connected with the positive electrode of the diode D a and the contact 1 of the relay JK a respectively, and the negative electrode of the diode D a is electrically connected with the contact 2 of the relay JK aContact 2 is connected to power supply VCC5. Relay JK a Contact 4 is electrically connected to the corresponding Ai input terminal of connector J1, and contact 3 is electrically connected to the positive terminal of the ohmmeter.

[0046] Among them, resistor R can be selected f The resistance is 680 ohms, and the tolerance is 1%; resistor R g The resistance is 47 kΩ and the tolerance is 1%.

[0047] like Figure 11 As shown, the Ai_O output unit includes a resistor R. h resistance R h One end is electrically connected to the PCi pin on the MCU, and the resistor R h The other end is electrically connected to resistor R. j and transistor Q d The base b, resistor R j The other end is connected to transistor Q. d The emitter (e) of the transistor is grounded; transistor Q d The collectors c are electrically connected to diode D respectively. b The positive terminal and relay JK b Contact 1, diode D b The negative terminal and relay JK b Contact 2 is connected to power supply VCC5. Relay JK b Contact 4 is electrically connected to the corresponding Ai_O output terminal of the J2 connector, and contact 3 is electrically connected to the negative terminal of the ohmmeter.

[0048] Among them, resistor R can be selected h The resistance is 10 kΩ, and the tolerance is 1%; resistor R j The resistance is 47 kΩ and the tolerance is 1%.

[0049] like Figure 12 As shown, the principle of resistance detection between the Ai signal input and the Ai_O signal output is as follows: the Ai signal of the device under test (DUT) is input to the positive terminal of the ohmmeter via a short-circuit detection and resistance detection device; the negative terminal of the ohmmeter outputs the Ai_O signal, which is then output to the DUT via the short-circuit detection and resistance detection device. The detection principle for other signals A1, A2, A3, etc., is similar. The detection device can perform resistance switching detection between multiple signals of the DUT from input to output.

[0050] like Figure 13As shown, the power supply unit includes a toggle switch SW1. The normally open terminal T1 of the toggle switch SW1 is electrically connected to pin 1 of the P1 interface; the normally closed terminal T2 of the toggle switch SW1 is grounded; the common terminal S1 of the toggle switch SW1 is electrically connected to the transient suppression diode D1 and the fuse F1; the other end of the fuse F1 is electrically connected to capacitors C1 and C2 and the Vin pin of the voltage regulator chip U1; the Vout pin of the voltage regulator chip U1 is electrically connected to capacitors C3 and C4, diode D2 and the Vin pin of the voltage regulator chip U2; the Vout pin of the voltage regulator chip U2 is electrically connected to capacitors C5 and C6 and diode D3. Capacitors C3 and C4 are electrically connected to power supply VCC5, and capacitors C5 and C6 are electrically connected to power supply VCC3.3. Pins 2 and 3 of P1, capacitors C1 and C2, the GND pin of voltage regulator chip U1, capacitors C3 and C4, diode D2, the GND pin of voltage regulator chip U2, capacitors C5 and C6, and diode D3 are all grounded.

[0051] like Figure 14 As shown, power supply VCC3.3 is connected in sequence to resistor R1 and the positive terminal of LED1, while the negative terminal of LED1 is grounded. After the power is turned on, LED1 lights up.

[0052] Pin 1 of the P1 interface is 12V+. Selectable capacitors C1, C3, and C5 are all 100nF with a rated voltage of 50V; capacitors C2, C4, and C6 are all 10μF with a rated voltage of 50V; resistor R1 has a resistance of 1kΩ and a tolerance of 1%. Diodes D2 and D3 are reserved diodes and are not installed by default.

[0053] like Figure 15 As shown, the circuit board assembly is located inside the housing. On the housing surface are the main power switch (SW1), short-circuit detection switch (SW2), short-circuit detection pause switch (SW3), resistance detection switch (SW4), and resistance detection pause switch (SW5). The housing surface also has i+1 short-circuit detection indicator lights and i capacitance detection indicator lights, where the short-circuit detection indicator light A0 is a light-emitting diode (LED). a The Ai signal light is LEDn+1; the capacitance detection signal light Ai is the LED corresponding to group i. b .

[0054] The casing surface has positive and negative input ports for the ohmmeter, as well as an IN terminal (external input) and an OUT terminal (external output). The ohmmeter's positive terminal is connected to the i-th relay JK in the Ai input terminal. a Contact 3 is electrically connected, and the negative terminal of the ohmmeter is connected to the i-th relay JK in the Ai_O output terminal. bThe contact 3 is electrically connected. The IN end is the J1 connector, and the OUT end is the J2 connector. The signal input end X1 connector of the measured member is inserted into the IN end, and the signal output end X2 connector of the measured member is inserted into the OUT end. Handles are further arranged on both sides of the shell.

[0055] The detection method of the short circuit and resistance value detection device adopts the short circuit and resistance value detection device, and includes a short circuit detection method and a resistance value detection method. Step 1, connect the signal input end of the measured member to the X1 connector, and connect the signal output end of the measured member to the X2 connector; connect the X1 connector to the J1 connector and the X2 connector to the J2 connector; thereby connecting all signals of the measured member to the short circuit and resistance value detection device.

[0056] Step 2, close the power switch SW1, and the system is powered on. When the light-emitting diode LED1 is bright, it indicates that the system is powered on normally.

[0057] Step 3, short circuit detection.

[0058] Close the short circuit detection switch SW2, and PA0, PA1, …, PAn output high level in turn. When PA0 outputs high level, A0 signal performs short circuit detection on A1 signal, …, An signal and ground signal in turn; when A0 signal has no short circuit condition with other signals, the light-emitting diode LED a is bright, then PA1 outputs high level in turn; when A0 signal is short-circuited with An signal, the light-emitting diode LED a and the light-emitting diode LEDn+1 are bright, and other light-emitting diodes are not bright.

[0059] When PAm outputs high level, Am signal performs short circuit detection on Am+1 signal, …, An signal and ground signal in turn; when Am signal has no short circuit condition with other signals, the light-emitting diode LEDm+1 is bright, then PAm+1 outputs high level in turn; if Am signal is short-circuited with An signal, the light-emitting diode LEDm+1 and LEDn+1 are bright, and other light-emitting diodes are not bright; n is greater than m+1.

[0060] By analogy, the detection of whether any two of A0, …, An signal and ground signal are short-circuited is completed, and there are n+2 signals in total.

[0061] Step 4, short circuit detection interruption.

[0062] When two signals are short-circuited, close the SW3 switch to interrupt the short circuit detection, record the fault, and then open the SW3 switch to continue the detection.

[0063] The resistance value detection method is implemented according to the following steps: Step 1, the measured piece signal input end is connected to X1 connector, the measured piece signal output end is connected to X2 connector; X1 connector is connected with J1 connector, X2 connector is connected with J2 connector; the positive pole of ohmmeter is electrically connected to the ohmmeter positive connection hole of short circuit and resistance detection device, that is, the contact 3 of i relays JK in Ai input end unit; the negative pole of ohmmeter is electrically connected to the ohmmeter negative connection hole of short circuit and resistance detection device, that is, the contact 3 of i relays JK in Ai_O output end. a b

[0064] Step 2, close the power switch SW1, system power supply, when the light emitting diode LED1 is bright, it indicates that the system power supply is normal.

[0065] Step 3, resistance detection.

[0066] Close the resistance detection switch SW4, PC0~PCi of MCU outputs high level in turn. In turn, signal A0 (input end) A0_O (output end), …, Ai (input end) Ai_O (output end) is connected between the positive and negative of ohmmeter, when i group signals are detected, then the corresponding light emitting diode LED of i group signals is lighted on. The corresponding resistance value of i group is read by ohmmeter. b

[0067] Step 4, resistance interruption detection.

[0068] When any signal resistance detection abnormal situation occurs, close SW5 switch, interrupt resistance detection, record fault, and then open SW5 switch to continue resistance detection.

[0069] When the external signal is A0~A15, a total of 16, the signal connection mode of short circuit and resistance detection device is shown in Figure 1 , the rectangular connector can use J29A series rectangular connector. As shown in Figure 16 , the input end of J1 connector of short circuit and resistance detection device is connected with A0~A15, a total of 16 input signals. As shown in Figure 17 , the output end of J2 connector of short circuit and resistance detection device is connected with A0_O~A15_O, a total of 16 output signals.

[0070] As shown in Figure 18 , when short circuit detection, short circuit detection switch SW2 is closed to ground, PA0~PA8, PA11~PA12, PA15, PB0~PB1, PB3~PB4 of MCU outputs high level in turn.

[0071] ​​​When PA0 outputs high level, the corresponding triode+MOS switch combination circuit is turned on, and at the same time, it is detected whether A0 signal is short-circuited to A1-A15 signal and ground signal (A16) respectively. If A0 signal is not short-circuited to other signals, only light-emitting diode LED a is bright, if A0 signal is only short-circuited to A1 signal, light-emitting diode LED a and light-emitting diode LED2 are bright, and other light-emitting diodes are not bright.

[0072] When PA1 outputs high level, the corresponding triode+MOS switch combination circuit is turned on, and at the same time, it is detected whether A1 signal is short-circuited to A2-A15 signal and ground signal (A16) respectively. If A1 signal is not short-circuited to other signals, only light-emitting diode LED2 is bright, if A1 signal is only short-circuited to A4 signal, light-emitting diode LED2 and light-emitting diode LED5 are bright, and other light-emitting diodes are not bright. In this way, whether any two of 17 signals are short-circuited is detected.

[0073] When resistance value detection, resistance value detection switch SW4 is closed to ground, PC0-PC15 of MCU outputs high level in turn, VCC5 outputs 5V voltage, triode is turned on, and relay (JK1 and JK3) contact is attracted to close. A0(input)A0_O(output), A1(input)A1_O(output), A2(input)A2_O(output)…A15(input)A15_O(output) are connected between the positive and negative of ohmmeter in turn, resistance value detection of all signal input to output end is realized, and when a group of signals is detected, the corresponding light-emitting diode is lighted, and resistance value is read through ohmmeter.

[0074] Embodiment 1 Short circuit and resistance value detection device, including circuit board assembly, circuit board assembly is electrically connected with rectangular connector, circuit board assembly includes MCU, MCU is electrically connected with power supply unit, switch unit and detection unit respectively; switch unit includes short circuit detection switch unit, short circuit detection interrupt switch unit, resistance value detection switch unit, resistance value detection interrupt switch unit; detection unit includes short circuit detection unit and resistance value detection unit; MCU includes a plurality of PA pins and a plurality of PC pins, PA pin includes PA0 pin and PAn pin, PC pin includes PCi pin; n=1…n, i=0…i.

[0075] Embodiment 2 The short circuit and resistance value detection device comprises a circuit board assembly, the circuit board assembly is electrically connected with a rectangular connector, the circuit board assembly comprises an MCU, the MCU is electrically connected with a power supply unit, a switch unit and a detection unit respectively; the switch unit comprises a short circuit detection switch unit, a short circuit detection interrupt switch unit, a resistance value detection switch unit and a resistance value detection interrupt switch unit; the detection unit comprises a short circuit detection unit and a resistance value detection unit; the MCU comprises a plurality of PA pins and a plurality of PC pins, the PA pins comprise a PA0 pin and a PAn pin, and the PC pins comprise a PCi pin; n = 1 …… n, i = 0 …… i.

[0076] The rectangular connector comprises two groups, namely a first rectangular connector and a second rectangular connector, the first rectangular connector comprises an X1 connector and a J1 connector, and the second rectangular connector comprises an X2 connector and a J2 connector; the J1 connector comprises a plurality of input ends Ai, and the J2 connector comprises a plurality of output ends Ai_O. The short circuit detection switch unit comprises a button switch SW2, the normally open end T1 of the button switch SW2 is electrically connected with a resistor R2, the other end of the resistor R2 is electrically connected with a power supply VCC3.3, and the common end S1 of the button switch SW2 is electrically connected with a capacitor C7, a pin 58 of the MCU and the common end S1 of a button switch SW1 respectively; the normally closed end T2 of the button switch SW2 and the other end of the capacitor C7 are both grounded. The short circuit detection interrupt switch unit comprises a button switch SW3, the normally open end T1 of the button switch SW3 is electrically connected with a resistor R5, the other end of the resistor R5 is electrically connected with the power supply VCC3.3, and the common end S1 of the button switch SW3 is electrically connected with a capacitor C9, a pin 59 of the MCU and the common end S1 of the button switch SW2 respectively; the normally closed end T2 of the button switch SW3 and the other end of the capacitor C9 are both grounded. The resistance value detection switch unit comprises a button switch SW4, the normally open end T1 of the button switch SW4 is electrically connected with a resistor R10, the other end of the resistor R10 is electrically connected with the power supply VCC3.3, and the common end S1 of the button switch SW4 is electrically connected with a capacitor C12, a pin 61 of the MCU and the common end S1 of the button switch SW3 respectively; the normally closed end of the button switch SW4 and the other end of the capacitor C12 are both grounded. The resistance value detection interrupt switch unit comprises a button switch SW5, the normally open end T1 of the button switch SW5 is electrically connected with a resistor R11, the other end of the resistor R11 is electrically connected with the power supply VCC3.3, and the common end S1 of the button switch SW5 is electrically connected with a capacitor C22, a pin 62 of the MCU and the common end S1 of the button switch SW4 respectively; the normally closed end T2 of the button switch SW5 and the other end of the capacitor C22 are both grounded.

[0077] Embodiment 3 The short circuit and resistance value detection device comprises a circuit board assembly, the circuit board assembly is electrically connected with a rectangular connector, the circuit board assembly comprises an MCU, the MCU is electrically connected with a power supply unit, a switch unit and a detection unit respectively; the switch unit comprises a short circuit detection switch unit, a short circuit detection interrupt switch unit, a resistance value detection switch unit and a resistance value detection interrupt switch unit; the detection unit comprises a short circuit detection unit and a resistance value detection unit; the MCU comprises a plurality of PA pins and a plurality of PC pins, the PA pins comprise a PA0 pin and a PAn pin, and the PC pins comprise a PCi pin; n = 1 …… n, and i = 0 …… i.

[0078] The rectangular connector comprises two groups, namely a first rectangular connector and a second rectangular connector, the first rectangular connector comprises an X1 connector and a J1 connector, and the second rectangular connector comprises an X2 connector and a J2 connector; the J1 connector comprises a plurality of input ends Ai, and the J2 connector comprises a plurality of output ends Ai_O. The short circuit detection switch unit comprises a button switch SW2, the normally open end T1 of the button switch SW2 is electrically connected with a resistor R2, the other end of the resistor R2 is electrically connected with a power supply VCC3.3, and the common end S1 of the button switch SW2 is electrically connected with a capacitor C7, a pin 58 of the MCU and the common end S1 of a button switch SW1 respectively; the normally closed end T2 of the button switch SW2 and the other end of the capacitor C7 are both grounded. The short circuit detection interrupt switch unit comprises a button switch SW3, the normally open end T1 of the button switch SW3 is electrically connected with a resistor R5, the other end of the resistor R5 is electrically connected with a power supply VCC3.3, and the common end S1 of the button switch SW3 is electrically connected with a capacitor C9, a pin 59 of the MCU and the common end S1 of the button switch SW2 respectively; the normally closed end T2 of the button switch SW3 and the other end of the capacitor C9 are both grounded. The resistance value detection switch unit comprises a button switch SW4, the normally open end T1 of the button switch SW4 is electrically connected with a resistor R10, the other end of the resistor R10 is electrically connected with a power supply VCC3.3, and the common end S1 of the button switch SW4 is electrically connected with a capacitor C12, a pin 61 of the MCU and the common end S1 of the button switch SW3 respectively; the normally closed end of the button switch SW4 and the other end of the capacitor C12 are both grounded. The resistance value detection interrupt switch unit comprises a button switch SW5, the normally open end T1 of the button switch SW5 is electrically connected with a resistor R11, the other end of the resistor R11 is electrically connected with a power supply VCC3.3, and the common end S1 of the button switch SW5 is electrically connected with a capacitor C22, a pin 62 of the MCU and the common end S1 of the button switch SW4 respectively; the normally closed end T2 of the button switch SW5 and the other end of the capacitor C22 are both grounded.

[0079] The power supply unit includes a button switch SW1, the normally open end T1 of the button switch SW1 is electrically connected to the pin 1 of the P1 interface, the common end S1 of the button switch SW1 is respectively electrically connected to the transient suppression diode D1 and the fuse F1; the other end of the fuse F1 is respectively electrically connected to the capacitor C1, the capacitor C2 and the Vin pin of the voltage stabilizing chip U1; the Vout pin of the voltage stabilizing chip U1 is respectively electrically connected to the capacitor C3, the capacitor C4 and the Vin pin of the voltage stabilizing chip U2; the Vout pin of the voltage stabilizing chip U2 is respectively electrically connected to the capacitor C5 and the capacitor C6; the power supply VCC5 is electrically connected between the capacitor C3 and the capacitor C4, and the power supply VCC3.3 is electrically connected between the capacitor C5 and the capacitor C6; The pin 2 and the pin 3 of the P1, the normally closed end T2 of the button switch SW1, the capacitor C1, the capacitor C2, the GND pin of the voltage stabilizing chip U1, the capacitor C3, the capacitor C4, the GND pin of the voltage stabilizing chip U2, the capacitor C5 and the capacitor C6 are commonly grounded; The power supply VCC3.3 is electrically connected to the resistor R1 and the anode of the light emitting diode LED1 in sequence, and the cathode of the light emitting diode LED1 is grounded.

[0080] Embodiment 4 The short circuit and resistance value detection device includes a circuit board assembly, the circuit board assembly is electrically connected to a rectangular connector, the circuit board assembly includes an MCU, the MCU is respectively electrically connected to a power supply unit, a switch unit and a detection unit; the switch unit includes a short circuit detection switch unit, a short circuit detection interrupt switch unit, a resistance value detection switch unit and a resistance value detection interrupt switch unit; the detection unit includes a short circuit detection unit and a resistance value detection unit; the MCU includes a plurality of PA pins and a plurality of PC pins, the PA pins include a PA0 pin and a PAn pin, and the PC pins include a PCi pin; n=1……n, i=0……i.

[0081] The rectangular connector includes two groups in total, including a first rectangular connector and a second rectangular connector, the first rectangular connector includes an X1 connector and a J1 connector, and the second rectangular connector includes an X2 connector and a J2 connector; the J1 connector includes a plurality of input ends Ai, and the J2 connector includes a plurality of output ends Ai_O; The short circuit detection switch unit includes a button switch SW2, the normally open end T1 of the button switch SW2 is electrically connected to the resistor R2, the other end of the resistor R2 is electrically connected to the power supply VCC3.3, the common end S1 of the button switch SW2 is respectively electrically connected to the capacitor C7, the pin 58 of the MCU and the common end S1 of the button switch SW1; the normally closed end T2 of the button switch SW2 and the other end of the capacitor C7 are both grounded; The short circuit detection interrupt switch unit includes a button switch SW3, the normally open end T1 of the button switch SW3 is electrically connected with a resistor R5, the other end of the resistor R5 is electrically connected with a power supply VCC3.3, the common end S1 of the button switch SW3 is electrically connected with a capacitor C9, a pin 59 of an MCU and the common end S1 of a button switch SW2 respectively; the normally closed end T2 of the button switch SW3 and the other end of the capacitor C9 are grounded. The resistance detection switch unit includes a button switch SW4, the normally open end T1 of the button switch SW4 is electrically connected with a resistor R10, the other end of the resistor R10 is electrically connected with a power supply VCC3.3, the common end S1 of the button switch SW4 is electrically connected with a capacitor C12, a pin 61 of an MCU and the common end S1 of the button switch SW3 respectively; the normally closed end of the button switch SW4 and the other end of the capacitor C12 are grounded. The resistance detection interrupt switch unit includes a button switch SW5, the normally open end T1 of the button switch SW5 is electrically connected with a resistor R11, the other end of the resistor R11 is electrically connected with a power supply VCC3.3, the common end S1 of the button switch SW5 is electrically connected with a capacitor C22, a pin 62 of an MCU and the common end S1 of the button switch SW4 respectively; the normally closed end T2 of the button switch SW5 and the other end of the capacitor C22 are grounded.

[0082] The power supply unit includes a button switch SW1, the normally open end T1 of the button switch SW1 is electrically connected with a pin 1 of a P1 interface, the common end S1 of the button switch SW1 is electrically connected with a transient voltage suppressor D1 and a fuse F1 respectively; the other end of the fuse F1 is electrically connected with a capacitor C1, a capacitor C2 and a Vin pin of a voltage stabilizing chip U1 respectively; a Vout pin of the voltage stabilizing chip U1 is electrically connected with a capacitor C3, a capacitor C4 and a Vin pin of a voltage stabilizing chip U2 respectively; a Vout pin of the voltage stabilizing chip U2 is electrically connected with a capacitor C5, a capacitor C6 respectively; a power supply VCC5 is electrically connected between the capacitor C3 and the capacitor C4, a power supply VCC3.3 is electrically connected between the capacitor C5 and the capacitor C6. The pin 2 and the pin 3 of the P1, the normally closed end T2 of the button switch SW1, the capacitor C1, the capacitor C2, a GND pin of the voltage stabilizing chip U1, the capacitor C3, the capacitor C4, a GND pin of the voltage stabilizing chip U2, the capacitor C5 and the capacitor C6 are grounded together. The power supply VCC3.3 is electrically connected with a resistor R1 and the anode of a light emitting diode LED1 in sequence, the cathode of the light emitting diode LED1 is grounded.

[0083] The short circuit detection unit comprises a PA0 short circuit detection unit and a PAn short circuit detection unit. The PA0 short circuit detection unit comprises a field effect transistor Q1, the collector S of the field effect transistor Q1 is electrically connected with a resistor R13, a capacitor C23 and a power supply VCC5 respectively, the gate G is electrically connected with a resistor R14 and the collector 3 of a transistor Q2 in sequence, the drain D is electrically connected with a resistor R12 and an A0 input end in the J1 connector in sequence; the other end of the resistor R13 and the other end of the capacitor C23 are commonly electrically connected between the gate G and the resistor R14; the base 1 of the transistor Q2 is electrically connected with a resistor R15 and a resistor R16 respectively, the other end of the resistor R15 is electrically connected with an emitting electrode 2 and ground in sequence, and the other end of the resistor R16 is electrically connected with the emitter 2 and ground in common. a The pin PA0 of the MCU and the emitter 2. The PAn short circuit detection unit comprises a field effect transistor Q a , the collector S of the field effect transistor Q a is electrically connected with a resistor R a , a capacitor C a and a power supply VCC5 respectively, the gate G is electrically connected with a resistor R b and the collector 3 of a transistor Q b in sequence, the drain D is electrically connected with a resistor R e and an An output end in sequence, the An output end is electrically connected with a corresponding Ai input end in the J1 connector, and the An output end is further electrically connected with a positive electrode of a light emitting diode LEDn+1, and a negative electrode of the light emitting diode LEDn+1 is grounded; the other end of the resistor R a and the other end of the capacitor C a are commonly electrically connected between the gate G and the resistor R b ; the base 1 of the transistor Q b is electrically connected with a resistor R c and a resistor R d respectively, the other end of the resistor R c is electrically connected with a pin PAn on the MCU, and the other end of the resistor R d is electrically connected with the emitter 2 and ground in common.

[0084] Embodiment 5 The detection method of the short circuit and resistance value detection device adopts the short circuit and resistance value detection device, and comprises a short circuit detection method and a resistance value detection method.

[0085] Embodiment 6 The detection method of the short circuit and resistance value detection device adopts the short circuit and resistance value detection device, and comprises a short circuit detection method and a resistance value detection method.

[0086] The short circuit detection method is implemented according to the following steps: Step 1, connecting the signal input end of the measured member with the X1 connector, connecting the signal output end of the measured member with the X2 connector; connecting the X1 connector with the J1 connector, and connecting the X2 connector with the J2 connector; Step 2, close the power switch SW1; Step 3, short circuit detection; Close the short circuit detection switch SW2, PA0, PA1…PAn output high level in turn; When PA0 outputs high level, A0 signal in turn carries out short circuit detection to A1 signal…An signal, ground signal; When A0 signal has no short circuit condition to other signals, light emitting diode LED a is bright, then turn to PA1 output high level; When A0 signal is short-circuited to An signal, light emitting diode LED a n+1 is bright, and other light emitting diodes are not bright; When PAm outputs high level, Am signal in turn carries out short circuit detection to Am+1 signal…An signal, ground signal; When Am signal has no short circuit condition to other signals, light emitting diode LEDm+1 is bright, then turn to PAm+1 output high level; If Am signal is short-circuited to An signal, light emitting diode LEDm+1 and light emitting diode LEDn+1 are bright, and other light emitting diodes are not bright; n is greater than m+1; Step 4, short circuit detection interruption; When two two signal short circuit condition occurs, close SW3 switch, interrupt short circuit detection, record fault, and then open SW3 switch to continue detection; Resistance detection method is implemented according to the following steps: Step 1, connect the signal input end of the measured piece to X1 connector, and connect the signal output end of the measured piece to X2 connector; Connect X1 connector with J1 connector, and connect X2 connector with J2 connector; The positive electrode of ohmmeter is electrically connected to the contact 3 of i relays JK a in Ai input end unit, and the negative electrode of ohmmeter is electrically connected to the contact 3 of i relays JK b in Ai_O output end; Step 2, close the power switch SW1; Step 3, resistance detection; Close resistance detection switch SW4, PC0~PCi of MCU outputs high level in turn; Connect signals A0, A0_O, …, Ai, Ai_O between the positive and negative of ohmmeter in turn, when i groups of signals are detected, the light emitting diode LED b corresponding to i groups of signals is lit; The resistance value corresponding to i groups is read by ohmmeter; Step 4, resistance interruption detection; When any signal resistance detection abnormal condition occurs, close SW5 switch, interrupt resistance detection, record fault, and then open SW5 switch to continue resistance detection.

Claims

1. A short-circuit and resistance detection device, characterized in that, The device includes a circuit board assembly electrically connected to a rectangular connector. The circuit board assembly includes an MCU, which is electrically connected to a power supply unit, a switching unit, and a detection unit. The switching unit includes a short-circuit detection switch unit, a short-circuit detection interrupt switch unit, a resistance detection switch unit, and a resistance detection interrupt switch unit. The detection unit includes a short-circuit detection unit and a resistance detection unit. The MCU includes several PA pins and several PC pins. The PA pins include PA0 pins and PAn pins, and the PC pins include PCi pins; n=1…n, i=0…i.

2. The short-circuit and resistance detection device according to claim 1, characterized in that, The rectangular connectors consist of two sets, including a first rectangular connector and a second rectangular connector. The first rectangular connector includes an X1 connector and a J1 connector, and the second rectangular connector includes an X2 connector and a J2 connector. The J1 connector includes several input terminals Ai, and the J2 connector includes several output terminals Ai_O. The short-circuit detection switch unit includes a toggle switch SW2. The normally open terminal T1 of the toggle switch SW2 is electrically connected to a resistor R2. The other end of the resistor R2 is electrically connected to the power supply VCC3.

3. The common terminal S1 of the toggle switch SW2 is electrically connected to a capacitor C7, a pin 58 of the MCU, and the common terminal S1 of the toggle switch SW1. The normally closed terminal T2 of the toggle switch SW2 and the other end of the capacitor C7 are both grounded. The short-circuit detection interrupt switch unit includes a toggle switch SW3. The normally open terminal T1 of the toggle switch SW3 is electrically connected to a resistor R5. The other end of the resistor R5 is electrically connected to the power supply VCC3.

3. The common terminal S1 of the toggle switch SW3 is electrically connected to a capacitor C9, a pin 59 of the MCU, and the common terminal S1 of the toggle switch SW2. The normally closed terminal T2 of the toggle switch SW3 and the other end of the capacitor C9 are both grounded. The resistance detection switch unit includes a toggle switch SW4. The normally open terminal T1 of the toggle switch SW4 is electrically connected to a resistor R10. The other end of the resistor R10 is electrically connected to the power supply VCC3.

3. The common terminal S1 of the toggle switch SW4 is electrically connected to a capacitor C12, a pin 61 of the MCU, and the common terminal S1 of the toggle switch SW3. The normally closed terminal of the toggle switch SW4 and the other end of the capacitor C12 are both grounded. The resistance detection interruption switch unit includes a toggle switch SW5. The normally open terminal T1 of the toggle switch SW5 is electrically connected to a resistor R11. The other end of the resistor R11 is electrically connected to the power supply VCC3.

3. The common terminal S1 of the toggle switch SW5 is electrically connected to a capacitor C22, a pin 62 of the MCU, and the common terminal S1 of the toggle switch SW4. The normally closed terminal T2 of the toggle switch SW5 and the other end of the capacitor C22 are both grounded.

3. The short-circuit and resistance detection device according to claim 2, characterized in that, The power supply unit includes a toggle switch SW1. The normally open terminal T1 of the toggle switch SW1 is electrically connected to pin 1 of the P1 interface. The common terminal S1 of the toggle switch SW1 is electrically connected to the transient suppression diode D1 and the fuse F1. The other end of the fuse F1 is electrically connected to capacitors C1 and C2 and the Vin pin of the voltage regulator chip U1. The Vout pin of the voltage regulator chip U1 is electrically connected to capacitors C3 and C4 and the Vin pin of the voltage regulator chip U2. The Vout pin of the voltage regulator chip U2 is electrically connected to capacitors C5 and C6. Capacitors C3 and C4 are electrically connected to power supply VCC5, and capacitors C5 and C6 are electrically connected to power supply VCC3.

3. Pins 2 and 3 of P1, normally closed terminal T2 of toggle switch SW1, capacitors C1 and C2, GND pin of voltage regulator chip U1, capacitors C3 and C4, GND pin of voltage regulator chip U2, capacitors C5 and C6 are all grounded. Power supply VCC3.3 is connected in sequence to resistor R1 and the positive terminal of LED1, while the negative terminal of LED1 is grounded.

4. The short-circuit and resistance detection device according to claim 3, characterized in that, The short-circuit detection unit includes a PA0 short-circuit detection unit and a PAn short-circuit detection unit. The PA0 short-circuit detection unit includes a field-effect transistor Q1. The collector S of the field-effect transistor Q1 is electrically connected to a resistor R13, a capacitor C23, and a power supply VCC5. The gate G is electrically connected to a resistor R14 and the collector 3 of a transistor Q2. The drain D is electrically connected to a resistor R12 and the A0 input terminal of the J1 connector. The other end of the resistor R13 and the other end of the capacitor C23 are electrically connected together between the gate G and the resistor R14. The base 1 of the transistor Q2 is electrically connected to a resistor R15 and a resistor R16. The other end of the resistor R15 is electrically connected to a light-emitting diode (LED). a The other end of resistor R16 is grounded together with pin PA0 of the MCU and emitter 2; The PAn short-circuit detection unit includes a field-effect transistor Q. a The field-effect transistor Q a The collector S is electrically connected to resistor R respectively. a Capacitor C a The power supply VCC5 and the gate G are connected in sequence to resistor R. b and transistor Q b The collector 3 and drain D are connected in sequence to resistor R. e The An output terminal is electrically connected to the corresponding Ai input terminal of connector J1. The An output terminal is also electrically connected to the positive terminal of LEDn+1, and the negative terminal of LEDn+1 is grounded; resistor R... a The other end and capacitor C a The other end is electrically connected to the gate G and the resistor R. b Between; transistor Q b The base 1 is electrically connected to resistor R. c and resistance R d resistance R c The other end is electrically connected to pin PAn on the MCU, and resistor R d The other end is grounded together with emitter 2.

5. The short-circuit and resistance detection device according to claim 4, characterized in that, The resistance detection unit includes an Ai input terminal unit and an Ai_O output terminal unit. The Ai input terminal unit includes a light-emitting diode (LED). b The light-emitting diode (LED) b The positive terminal is electrically connected to the PCi pin on the MCU, and the negative terminal is electrically connected to resistor R. f resistance R f Connect resistor R respectively g and transistor Q c The base b, resistor R g The other end is connected to transistor Q. c The emitter (e) of the transistor is grounded; transistor Q c The collectors c are electrically connected to diode D respectively. a The positive terminal and relay JK a Contact 1, diode D a The negative terminal and relay JK a Contact 2 is connected to power supply VCC5; Relay JK a Contact 4 is electrically connected to the corresponding Ai input terminal of connector J1, and contact 3 is electrically connected to the positive terminal of the ohmmeter. The Ai_O output terminal unit includes a resistor R. h resistance R h One end is electrically connected to the PCi pin on the MCU, and the resistor R h The other end is electrically connected to resistor R. j and transistor Q d The base b, resistor R j The other end is connected to transistor Q. d The emitter (e) of the transistor is grounded; transistor Q d The collectors c are electrically connected to diode D respectively. b The positive terminal and relay JK b Contact 1, diode D b The negative terminal and relay JK b Contact 2 is connected to power supply VCC5; Relay JK b Contact 4 is electrically connected to the corresponding Ai_O output terminal of the J2 connector, and contact 3 is electrically connected to the negative terminal of the ohmmeter.

6. The short-circuit and resistance detection device according to claim 5, characterized in that, Pin 5 of the MCU is electrically connected to capacitor C8 and the input terminal of dual-electrode crystal oscillator Y1 respectively. The output terminal of dual-electrode crystal oscillator Y1 is connected to capacitor C10 and resistor R7 respectively. The other end of resistor R7 is connected to pin 6 of the MCU. The connection point of capacitor C8 and capacitor C10 is grounded together. Pin 43 of the MCU is electrically connected to pin 3 of P2, pin 42 of the MCU is electrically connected to pin 2 of P2, and pin 1 of P2 is grounded; pin 60 of the MCU is electrically connected to resistor R8 and power supply VCC3.3, with the other end of resistor R8 grounded; pin 7 of the MCU is electrically connected to the reset signal node RESET, which is electrically connected to resistor R9 and capacitor C11, with the other end of R9 connected to power supply VCC3.3 and the other end of capacitor C11 grounded; pin 13 of the MCU is electrically connected to ferrite bead FB1 and capacitors C15 and C16, with the other end of ferrite bead FB1 connected to power supply VCC3.3, and the other ends of capacitors C15 and C16 grounded; pin 28 of the MCU is electrically connected to pin BOOT1, resistor R4, and power supply VCC3.3, with the other end of resistor R4 grounded; MCU Pin 31 of the MCU is electrically connected to capacitor C14, with the other end of capacitor C14 grounded; pin 47 of the MCU is electrically connected to capacitor C13, with the other end of capacitor C13 grounded; pins 63, 18, and 12 of the MCU are all grounded; pins 1, 32, 48, 64, and 19 of the MCU are all electrically connected to power supply VCC3.3; pins 49 and 46 of the MCU are electrically connected to download port P3; pin 1 of download port P3 is electrically connected to diode D7 and power supply VCC3.3, with the other end of diode D7 grounded; pin 2 of download port P3 is grounded; pin 3 of download port P3 is electrically connected to diode D6 and pin 49 of the MCU, with the other end of diode D6 grounded; pin 4 of download port P3 is electrically connected to diode D5 and pin 46 of the MCU, with the other end of diode D5 grounded.

7. The short-circuit and resistance detection device according to claim 6, characterized in that, The power supply VCC3.3 is also electrically connected to a filter circuit, which includes several capacitors. One end of capacitors C17, C18, C19, C20, and C21 is electrically connected to the power supply VCC3.3, and the other end is grounded together.

8. The short-circuit and resistance detection device according to claim 6, characterized in that, The capacitor C4 is electrically connected to the Vin pin of the voltage regulator chip U2 via diode D2. The capacitor C6 is also electrically connected to diode D3. Both diodes D2 and D3 are grounded. The pin 60 of the MCU is electrically connected to resistors R6 and R8, respectively. The other end of resistor R6 is electrically connected to power supply VCC3.

3. The pin 28 of the MCU is electrically connected to pin BOOT1, resistors R3 and R4, respectively. The other end of resistor R3 is electrically connected to power supply VCC3.

3.

9. A detection method for a short circuit and resistance detection device, characterized in that, The short-circuit and resistance detection device as described in claims 7-8 includes a short-circuit detection method and a resistance detection method.

10. The detection method of the short circuit and resistance detection device as described in claim 9, characterized in that, The short-circuit detection method is implemented according to the following steps: Step 1: Connect the signal input terminal of the device under test (DUT) to connector X1 and the signal output terminal of the DUT to connector X2; connect connector X1 to connector J1 and connector X2 to connector J2. Step 2: Close the power switch SW1; Step 3, short circuit detection; When the short-circuit detection switch SW2 is closed, PA0, PA1...PAn output high levels in sequence; When PA0 outputs a high level, the A0 signal sequentially performs short-circuit detection on the A1 signal...An signal, and ground signal; when the A0 signal does not short-circuit any other signal, the LED... a When the LED is lit, PA1 outputs a high level; when the A0 signal is short-circuited to the An signal, the LED... a Only LEDn+1 is lit, while the other LEDs are not lit. When PAm outputs a high level, the Am signal sequentially performs short-circuit detection on the Am+1 signal...An signal, and ground signal; when the Am signal does not short-circuit other signals, LEDm+1 lights up, and then it is PAm+1's turn to output a high level; if the Am signal short-circuits the An signal, LEDm+1 and LEDn+1 light up, while other LEDs do not light up; n is greater than m+1; Step 4, short circuit detection interrupted; When a short circuit occurs between two signals, close SW3 switch to interrupt the short circuit detection, record the fault, and then open SW3 switch to continue the detection. The resistance detection method is implemented according to the following steps: Step 1: Connect the signal input terminal of the device under test (DUT) to connector X1, and connect the signal output terminal of the DUT to connector X2; connect connector X1 to connector J1, and connector X2 to connector J2; connect the positive terminal of the ohmmeter to the i relays JK in the Ai input unit. a Contact 3 connects the negative terminal of the ohmmeter to the i-th relay JK in the Ai_O output terminal. b Contact point 3; Step 2: Close the power switch SW1; Step 3, resistance detection; When the resistance detection switch SW4 is closed, the MCU's PC0 to PCi output high levels sequentially. Connect signals A0, A0_O, ..., Ai, Ai_O sequentially between the positive and negative terminals of the ohmmeter. When the i-th group of signals is detected, the corresponding LED will... b Light it up; read the resistance value of group i using an ohmmeter; Step 4, resistance interruption detection; If any abnormality occurs in the resistance detection of any signal, close the SW5 switch to interrupt the resistance detection, record the fault, and then open the SW5 switch to continue the resistance detection.

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