Wire harness detection circuit

Abstract

The utility model discloses a wire harness detection circuit. The wire harness detection circuit comprises a square wave generation circuit, a counting circuit and a detection indication circuit, the square wave generation circuit is connected with the counting circuit; the counting circuit is connected to a first connection part of the wire harness to be detected; and the detection indication circuit is connected to the second connection part of the wire harness to be detected. The wire harness detection circuit provided by the utility model can automatically carry out multi-node connectivity detection, and the detection efficiency is improved; through the square wave generation circuit, the counting circuit and the detection indication circuit, a fault point can be rapidly and accurately positioned. A detection result can be visually displayed through devices such as an indicating lamp or a buzzer; by utilizing high-precision electronic components and advanced circuit design, the measurement precision higher than that of a traditional method can be provided.

Description

Technical Field

[0001] The utility model relates to the field of electronic detection equipment, in particular to a wire harness detection circuit. Background Art

[0002] With the increasing popularity of electronic devices, wiring harnesses are increasingly used in various electronic devices. The connectivity of wiring harnesses is directly related to the proper functioning of electronic devices. Traditional wiring harness detection methods using multimeters are often inefficient, inaccurate, and complex. Therefore, the development of a simple, efficient, and accurate wiring harness detection circuit is of great significance for improving the reliability and maintenance efficiency of electronic devices. Utility Model Content

[0003] The purpose of the utility model is to provide a wiring harness detection circuit to achieve efficient detection of the wiring harness of electronic equipment.

[0004] In order to solve the above technical problems, the utility model provides a wiring harness detection circuit, including: a square wave generating circuit, a counting circuit and a detection indication circuit; the square wave generating circuit is connected to the counting circuit; the counting circuit is connected to the first connection of the wiring harness to be tested; the detection indication circuit is connected to the second connection of the wiring harness to be tested.

[0005] Furthermore, it also includes a voltage isolation conversion circuit; one end of the voltage isolation conversion circuit is connected to the front-stage circuit of the wiring harness to be tested, and the other end is connected to the square wave generating circuit.

[0006] Furthermore, the square wave generating circuit includes a NE555 chip, a first capacitor, a second capacitor, a third capacitor, a first resistor and a second resistor; one end of the first capacitor and the second capacitor are connected to the positive pole of the power supply and the other end is grounded; one end of the third capacitor is connected to one end of the second resistor and the other end is grounded; one end of the first resistor is connected to the positive pole of the power supply and the other end is connected to the other end of the second resistor.

[0007] Furthermore, the 8th pin of the NE555 chip and the 4th pin of the NE555 chip are connected to the positive pole of the power supply, the 2nd pin of the NE555 chip is connected to the 6th pin of the NE555 chip and then to the third end of the second resistor, and the 7th pin of the NE555 chip is connected to the other end of the first resistor.

[0008] Furthermore, the counting circuit includes a CD4017B chip, a third resistor and a fourth capacitor; one end of the third resistor is grounded, and the other end is connected to the 15th pin of the CD4017B chip; one end of the fourth capacitor is connected to the positive pole of the power supply, and the other end is connected to the 15th pin of the CD4017B chip; the 13th pin of the CD4017B chip is grounded; the 14th pin of the CD4017B chip is connected to the 3rd pin of the NE555 chip; the 16th pin of the CD4017B chip is connected to the positive pole of the power supply; the 1-7 pins of the CD4017B chip and the 9-11 pins of the CD4017B chip are connected to the first connection of the wiring harness to be tested.

[0009] Furthermore, the detection indication circuit includes a plurality of LED lights, each of which is connected in series with a current-limiting resistor and then connected to the second connection point of the wiring harness to be tested.

[0010] Furthermore, the detection indication circuit also includes a buzzer and a NOR gate.

[0011] Furthermore, one end of the buzzer is connected to the NOR gate, and the other end is grounded; the NOR gate is also connected to the first connection point of the wiring harness to be tested and the second connection point of the wiring harness to be tested, respectively.

[0012] Furthermore, the number of the LED lamps, the current-limiting resistors, the NOR gates and the buzzers is the same.

[0013] Compared with the conventional multimeter in the prior art, the present invention has at least the following beneficial effects:

[0014] High efficiency: The wiring harness detection circuit proposed in the utility model can realize fast sequential scanning through the integrated square wave generation circuit, counting circuit and detection indication circuit, greatly improving the detection speed; traditional multimeter measurement requires manual replacement and testing of each node one by one, which is inefficient for complex wiring harnesses.

[0015] Fast fault location: The wiring harness detection circuit proposed in this utility model can intuitively display the detection results through output devices such as indicator lights or buzzers, helping users to quickly locate the fault node; traditional multimeters require users to manually determine the fault point based on the measurement results, which may be difficult for users who are not familiar with the operation.

[0016] Simple operation: The wiring harness detection circuit design proposed by this utility model is simple and easy to understand. The user only needs to connect the wiring harness and start the detection, which is convenient to operate. Using a traditional multimeter to detect the wiring harness requires multiple operations, which requires high professional knowledge and operating skills of the user.

[0017] Intuitive results: The wiring harness detection circuit proposed in the present invention can intuitively display the detection results through an integrated indicator device, which is easy for non-professionals to understand; the results of traditional multimeters usually need to be interpreted by users themselves, which may have a certain risk of misreading. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the structure of the wiring harness detection circuit in one embodiment of the present invention. DETAILED DESCRIPTION

[0019] The following is a more detailed description of the wiring harness detection circuit of the present invention, with reference to a schematic diagram, which illustrates a preferred embodiment of the present invention. It should be understood that those skilled in the art may modify the present invention as described herein while still achieving the beneficial effects of the present invention. Therefore, the following description should be understood as a general guide for those skilled in the art and not as a limitation of the present invention.

[0020] The following paragraphs describe the present invention in more detail by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are greatly simplified and not to exact scale, and are intended solely to facilitate and clearly illustrate the embodiments of the present invention.

[0021] Example 1

[0022] like Figure 1 As shown, an embodiment of the present invention proposes a wiring harness detection circuit, including: a square wave generating circuit, a counting circuit and a detection indication circuit; the square wave generating circuit is connected to the counting circuit; the counting circuit is connected to the first connection of the wiring harness to be tested; the detection indication circuit is connected to the second connection of the wiring harness to be tested.

[0023] In this embodiment, the wiring harness detection circuit also includes a voltage isolation conversion circuit; one end of the voltage isolation conversion circuit is connected to the front-stage circuit of the wiring harness to be tested, and the other end is connected to the square wave generating circuit; the voltage isolation conversion circuit can convert the front-stage circuit voltage V1 into the voltage V2 required by the wiring harness detection circuit of the utility model, thereby playing the role of isolating the voltage.

[0024] Furthermore, the voltage conversion circuit includes capacitors C4, C5, C6, C7, and C8, and an isolated power supply module. The power isolation module uses the WRB2405S-3WR2A. In this embodiment, C4 uses a 10μF capacitor, C5 uses a 100nF capacitor, C6 uses a 10μF capacitor, C7 uses a 100nF capacitor, and C8 uses a 10μF capacitor. These capacitors have filtering and energy storage functions. It will be understood that the above capacitor parameters are only examples, and those skilled in the art can flexibly select capacitors of other specifications based on actual conditions.

[0025] In this embodiment, the square wave generating circuit includes a NE555 chip, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first resistor R1 and a second resistor R2; one end of the first capacitor C1 and the second capacitor C2 are connected to the positive pole of the power supply and the other end is grounded; one end of the third capacitor C3 is connected to one end of the second resistor R2 and the other end is grounded; one end of the first resistor R1 is connected to the positive pole of the power supply and the other end is connected to the other end of the second resistor R2; the 8th pin of the NE555 chip and the 4th pin of the NE555 chip are connected to the positive pole of the power supply, the 2nd pin of the NE555 chip is connected to the 6th pin of the NE555 chip and then connected to the third end of the second resistor R2, and the 7th pin of the NE555 chip is connected to the other end of the first resistor R1.

[0026] Specifically, pin 1 of the NE555 chip is grounded and pin 8 is connected to the positive pole of the power supply; pin 4 is the reset pin. When pin 4 is connected to a high level, the NE555 chip works; the first resistor R1, the second resistor R2 and the third capacitor C3 provide voltage for pins 2 and 6. When the voltage of pins 2 and 6 is higher than 2 / 3 of V2, the output of pin 3 is a low level. When the voltage of pins 2 and 6 is lower than 1 / 3 of V2, the output of pin 3 is a high level; pin 7 is a discharge pin. The third capacitor C3 is connected to pin 7 through the second resistor R2 for discharge. The charging and discharging of the third capacitor C3 is used to control the pin voltage; the first capacitor C1 and the second capacitor C2 have the functions of filtering and energy storage.

[0027] Furthermore, when the entire square wave generation circuit begins operation, the third capacitor C3 begins charging, and the voltages at pins 2 and 6 increase. When the voltages at pins 2 and 6 rise to 2 / 3 of V2, the output of pin 3 is low, and pin 7 assumes a low impedance state relative to ground. The third capacitor C3 then discharges to ground through the second resistor R2 and pin 7. When the voltages at pins 2 and 6 fall below 1 / 3 of V2, the output of pin 3 is high, and pin 7 assumes a high impedance state relative to ground. The third capacitor C3 then begins charging again, thereby forming a stable pulse signal. By adjusting the resistance value of the second resistor R2, the time constant of the charge and discharge of the third capacitor C3 can be changed, thereby changing the frequency of the pulses output from pin 3. In this embodiment, as an example, a 10μF capacitor is selected for the first capacitor C1. A 100nF capacitor is selected for the second capacitor C2, a 1μF capacitor is selected for the third capacitor C3, a 2.2K resistor is selected for the first resistor R1, and a 50K resistor is selected for the second resistor R2. It is understandable that the above capacitor and resistor parameters are only examples, and those skilled in the art can flexibly select capacitors and resistors of other specifications according to actual conditions.

[0028] In this embodiment, the counting circuit includes a CD4017B chip, a third resistor R3 and a fourth capacitor C9; one end of the third resistor R3 is grounded, and the other end is connected to the 15th pin of the CD4017B chip; one end of the fourth capacitor C9 is connected to the positive pole of the power supply, and the other end is connected to the 15th pin of the CD4017B chip; the 13th pin of the CD4017B chip is grounded; the 14th pin of the CD4017B chip is connected to the 3rd pin of the NE555 chip; the 16th pin of the CD4017B chip is connected to the positive pole of the power supply; the 1-7 pins of the CD4017B chip and the 9-11 pins of the CD4017B chip are connected to the first connection of the wiring harness to be tested.

[0029] Specifically, CD4017B is a counting chip, and the 14th pin of the CD4017B chip is the input end of the pulse signal, and the rising edge is valid; the 15th pin is the reset pin, which is valid at a high level and is connected to V2 through the fourth capacitor C9. When the power is turned on, the fourth capacitor C9 is grounded through the third resistor R3 for charging. When charging just starts, the 15th pin is high and the output is cleared. After the fourth capacitor C9 is charged, the 15th pin is low, remains in an inoperative state, and starts normal counting; the pulse signal output by the 3rd pin of the NE5553 chip is used as the clock pulse input of the CD4017B chip. After the 14th pin of the CD4017B chip receives the pulse signal, the decimal counter starts counting, and outputs a high level in sequence from the 10 output ends, and the cycle continues; the 1st to 7th pins of the CD4017B chip and the 9th to 11th pins of the CD4017B chip are respectively provided with P1.1-P1.10 ports, and the P1.1-P1.10 ports are connected one-to-one with the wires at the first connection of the wiring harness to be tested. In this embodiment, the third resistor R3 is a 1K resistor and the fourth capacitor C9 is a 10μF capacitor. It is understood that the above capacitor and resistor parameters are only examples, and those skilled in the art can flexibly select capacitors of other specifications according to actual conditions.

[0030] In this embodiment, the detection indication circuit includes LDE1-LED10, and the LDE1-LED10 is connected in series with current-limiting resistors R4-R13 and then connected to the wires at the second connection of the wiring harness to be tested through ports P2.1-P2.10 in a one-to-one correspondence; the detection indication circuit also includes buzzers H1-H10 and NOR gates U1-U10; the buzzers H1-H10 are connected to the NOR gates U1-U10 in sequence through connections 3.1-3.10, and the other end is grounded; in this embodiment, the NOR gates U1-U10 use 74LVC1G02GV chips, and the second pins of the NOR gates U1-U10 are connected to the wires at the first connection of the wiring harness to be tested through ports P1.1-P1.10 in a one-to-one correspondence, and the first pins of the NOR gates U1-U10 are connected to the wires at the second connection of the wiring harness to be tested in a one-to-one correspondence through ports P2.1-P2.10. In this embodiment, the current limiting resistors R4-R13 are selected from resistors with a resistance of 297R-303R, preferably 298R, 300R, or 302R.

[0031] In this embodiment, ports P1.1-P1.10 of the wiring harness detection circuit proposed in the present invention are connected one-to-one with the wires at the first connection of the wiring harness to be tested, and ports P2.1-P2.10 are connected one-to-one with the wires at the second connection of the wiring harness to be tested. After the connections are completed and the circuit is started, when the wiring harness to be tested is conductive, LDE1-LED10 lights up in sequence, ports P2.1-P2.10 are all high, NOR gates U1-U10 do not work, and buzzers H1-H10 do not sound, indicating that the wiring harness to be tested is functioning normally. When there is a short circuit in the wiring harness to be tested, two or more LEDs in LDE1-LED10 light up continuously, and ports P2.1-P2.10 are all high. 10 is high level, the NOR gate U1-U10 does not work, and the buzzer H1-H10 does not sound, indicating that there is a short circuit between the wires connected to the long-on LED in the wiring harness to be tested; when there is an open circuit in the wiring harness to be tested, the LEDs in LDE1-LED10 connected to the open wires in the wiring harness to be tested go out, and among ports P2.1-P2.10, the ports connected to the open wires in the wiring harness to be tested are low level. In the NOR gate U1-U10, the NOR gate connected to the low-level port converts the input low level into a high level and outputs it to the connected buzzer. The connected buzzer sounds, indicating that there is an open circuit in the wires connected to the extinguished LED and the sounding buzzer.

[0032] In summary, the use of the wiring harness detection circuit proposed in the present invention to measure wiring harnesses has the following advantages compared to using a traditional multimeter to measure wiring harnesses:

[0033] High efficiency: The wiring harness detection circuit proposed in the utility model can realize fast sequential scanning through the integrated square wave generation circuit, counting circuit and detection indication circuit, greatly improving the detection speed; traditional multimeter measurement requires manual replacement and testing of each node one by one, which is inefficient for complex wiring harnesses.

[0034] Fast fault location: The wiring harness detection circuit proposed in this utility model can intuitively display the detection results through output devices such as indicator lights or buzzers, helping users to quickly locate the fault node; traditional multimeters require users to manually determine the fault point based on the measurement results, which may be difficult for users who are not familiar with the operation.

[0035] Simple operation: The wiring harness detection circuit design proposed by this utility model is simple and easy to understand. The user only needs to connect the wiring harness and start the detection, which is convenient to operate. Using a traditional multimeter to detect the wiring harness requires multiple operations, which requires high professional knowledge and operating skills of the user.

[0036] Intuitive results: The wiring harness detection circuit proposed in the present invention can intuitively display the detection results through an integrated indicator device, which is easy for non-professionals to understand; the results of traditional multimeters usually need to be interpreted by users themselves, which may have a certain risk of misreading.

[0037] Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A wiring harness detection circuit, characterized in that: include: Square wave generating circuit, counting circuit and detection indicating circuit; The square wave generating circuit is connected to the counting circuit; The counting circuit is connected to the first connection of the wiring harness to be tested; The detection indicating circuit is connected to the second connection of the wiring harness to be tested.

2. The wiring harness detection circuit according to claim 1, wherein: It also includes a voltage isolation conversion circuit; one end of the voltage isolation conversion circuit is connected to the front-stage circuit of the wiring harness to be tested, and the other end is connected to the square wave generating circuit.

3. The wiring harness detection circuit according to claim 1, wherein: The square wave generating circuit includes a NE555 chip, a first capacitor, a second capacitor, a third capacitor, a first resistor and a second resistor; one end of the first capacitor and the second capacitor are connected to the positive pole of the power supply and the other end is grounded; one end of the third capacitor is connected to one end of the second resistor and the other end is grounded; one end of the first resistor is connected to the positive pole of the power supply and the other end is connected to the other end of the second resistor.

4. The wiring harness detection circuit according to claim 3, wherein: The 8th pin of the NE555 chip and the 4th pin of the NE555 chip are connected to the positive pole of the power supply, the 2nd pin of the NE555 chip is connected to the 6th pin of the NE555 chip and then to the third end of the second resistor, and the 7th pin of the NE555 chip is connected to the other end of the first resistor.

5. The wiring harness detection circuit according to claim 4, wherein: The counting circuit includes a CD4017B chip, a third resistor and a fourth capacitor; one end of the third resistor is grounded, and the other end is connected to the 15th pin of the CD4017B chip; one end of the fourth capacitor is connected to the positive pole of the power supply, and the other end is connected to the 15th pin of the CD4017B chip; the 13th pin of the CD4017B chip is grounded; the 14th pin of the CD4017B chip is connected to the 3rd pin of the NE555 chip; the 16th pin of the CD4017B chip is connected to the positive pole of the power supply; pins 1-7 of the CD4017B chip and pins 9-11 of the CD4017B chip are connected to the first connection of the wiring harness to be tested.

6. The wiring harness detection circuit according to claim 1, wherein: The detection indication circuit includes a plurality of LED lights, each of which is connected in series with a current-limiting resistor and then connected to the second connection point of the wiring harness to be tested.

7. The wiring harness detection circuit according to claim 6, wherein: The detection indicating circuit further includes a buzzer and a NOR gate.

8. The wiring harness detection circuit according to claim 7, wherein: One end of the buzzer is connected to the NOR gate, and the other end is grounded; the NOR gate is also connected to the first connection point of the wiring harness to be tested and the second connection point of the wiring harness to be tested respectively.

9. The wiring harness detection circuit according to claim 8, wherein: The number of the LED lamps, the current-limiting resistors, the NOR gates and the buzzers is the same.

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