A universal wiring harness continuity tester and detection method

Abstract

A universal wire harness continuity detector and detection method, which relates to the field of wire harness continuity detection, includes a power module, an input module, a threshold selection module, a comparison circuit module and an output module, wherein the power module supplies power to the input module, the threshold selection module, the comparison circuit module and the output module; the input module provides a connection port for the tested wire harness, and realizes the connection between the positive and negative terminals and the tested wire through the test leads, so that the tested wire is connected to the threshold selection module; the threshold selection module is used to set the on-resistance value; the comparison circuit module compares the resistance of the tested wire and the set on-resistance value and the resistance of the internal voltage divider resistance according to the set on-resistance value and the resistance of the tested wire, obtains the comparison result, and outputs the comparison result to the output module; the output module obtains the comparison result of the comparison circuit module and outputs the comparison result. A variety of resistance conduction modes can be provided, with sensitive detection and high detection accuracy.

Description

Technical Field

[0001] The invention relates to a universal wire harness continuity tester, in particular to a universal electronic product wire harness continuity tester, which can accurately and quickly complete wire harness continuity inspection and testing. Background Art

[0002] At present, the internal integration of electronic products is getting higher and higher, the functions of the product interface circuits are becoming more and more abundant, and the number of wiring harnesses connecting the internal circuits and external interfaces is also increasing and becoming denser. In order to ensure the normal function of the product, it is necessary to conduct a wiring harness continuity check, and eliminate early faults and failures such as open circuits, short circuits, and miswiring in the product through continuity inspection. Conventional product inspections require a resistance value of less than 3Ω, and cables greater than 30 meters require a resistance value of less than 5Ω. At this stage, the ohm range of a digital multimeter is used to contact the wire cores or contacts one by one, and the values ​​displayed by the multimeter are observed at the same time to determine the correctness of the on, off, and resistance values. Due to the internal circuit characteristics of the multimeter, it takes 5s to 8s for the measured value to change from change to stability. At present, the total number of wiring harnesses in the contracted products, including the whole machine, cable, and box, will reach tens of thousands of points. The continuity inspection project process consumes a lot of time and is prone to the risk of human misjudgment.

[0003] With the continuous development of electronic product technology, higher requirements are also put forward for electronic product testing. The lack of accurate and efficient testing equipment is a problem that product manufacturers need to face. At present, domestic production units generally use general-purpose testing equipment, which cannot effectively set the resistance value for measurement. The conduction check of the product is completed by personnel judging the value size, which is time-consuming and labor-intensive to use, and there is also a risk of misjudgment. Summary of the invention

[0004] The technical problem solved by the present application is: to overcome the deficiencies of the prior art, to provide a wiring harness continuity tester that meets different resistance continuity requirements, to provide four resistance continuity modes, with sensitive detection and high detection accuracy.

[0005] The present invention proposes a universal wire harness continuity tester, which can accurately and quickly complete the wire harness continuity inspection. The universal type means that it can meet the measurement and inspection requirements of the wire harness continuity resistance threshold of different products, and provides four resistance continuity modes of 3Ω / 5Ω / 10Ω / 20Ω. The detection results are reflected immediately and with high accuracy.

[0006] The technical solutions provided by this application are as follows:

[0007] A universal wiring harness continuity detector includes a power module, an input module, a threshold selection module, a comparison circuit module and an output module.

[0008] A power module, which supplies power to the input module, the threshold selection module, the comparison circuit module and the output module;

[0009] An input module provides a connection port for the wiring harness under test, and is connected to the wire under test through the connection port, so that the wire under test is connected to the threshold selection module;

[0010] A threshold selection module, used to set the on-resistance value;

[0011] The comparison circuit module compares the resistance of the measured wire with the set on-resistance value according to the set on-resistance value and the resistance of the measured wire, obtains a comparison result, and outputs the comparison result to the output module;

[0012] The output module obtains the comparison result of the comparison circuit module and outputs the comparison result.

[0013] The threshold selection module includes a resistance adjustment module, a linkage switch and a plurality of resistors with different resistance values, the resistance adjustment module is connected to the first main road, one end of the first main road is connected to the output end of the power module, and the other end is connected to the linkage switch, the linkage switch includes a plurality of gear contacts, the gear contacts include a neutral contact and a plurality of electric block contacts, each electric block contact is connected to the first main connection road through a branch, and the other end of the first main connection road is connected to the input module; each branch road is provided with a resistor, and the resistance values ​​of the resistors connected to different branches are different;

[0014] The input module includes a P1 input terminal and a P2 input terminal, the P1 connection terminal is connected to the first main connection path, and the P2 input terminal is grounded through the output main path;

[0015] The comparison circuit module includes a first comparator and a second comparator. The first main connection path is connected to the negative input terminal of the first comparator through a first negative input wire. The output terminal of the power supply module is also connected to the second main path. The other end of the second main path is connected to the output module. The first measuring wire and the second measuring wire are sequentially connected in parallel between the second main path and the output main path. A resistor R10 and a resistor R11 are provided on the first measuring wire. The resistance values ​​of the resistor R10 and the resistor R11 are equal. The first measuring wire is connected to a first positive input wire between the resistor R10 and the resistor R11. The first positive input wire is connected to the positive input terminal of the first comparator. The first comparator is connected to the positive input terminal of the first comparator. A first output result is obtained according to the voltage of the first positive input wire and the first negative input wire; a resistor R14 and a resistor R15 are connected to the second measuring wire, the resistance values ​​of the resistor R14 and the resistor R15 are equal, a second positive input wire is connected to the second measuring wire between the resistor R14 and the resistor R15, the second positive input wire is connected to the positive input terminal of the second comparator, the first output line is connected to the negative input terminal of the second comparator, and the second comparator is connected to the second output line; the second comparator obtains a second output result according to the first output result of the first comparator and the voltage of the second positive input wire; the second output line is connected to the output module.

[0016] The resistance adjustment module includes a sliding resistor R3 and a resistor R4, and the sliding resistor R3 and the resistor R4 are connected to the first main circuit in parallel.

[0017] A resistor R9 is provided on the first main connection circuit, and a resistor R2 is connected to the first main circuit. The resistance values ​​of the resistor R9 and the resistor R2 are equal.

[0018] The output module comprises a display path one and a display path two which are connected in parallel, wherein the display path one is provided with an LED lamp, and the display path two is provided with a buzzer.

[0019] A first voltage stabilizing line is connected between the first main line and the first output line, and a resistor R13 is arranged on the first voltage stabilizing line. A second voltage stabilizing line is connected between the first measuring wire and the first voltage stabilizing line, and a resistor R12 is arranged on the second voltage stabilizing line.

[0020] It also includes a shell, and a power module, an input module, a threshold selection module, a comparison circuit module and an output module are all embedded and installed on the shell.

[0021] A detection method of a universal wiring harness continuity tester, comprising:

[0022] Start the power module;

[0023] Adjust the sliding resistor R3;

[0024] The resistance value of the on-resistance is set by a threshold selection module;

[0025] One end of the two test leads is connected to the connection input module, and the other end is connected to the two ends of the measured wire; the comparison circuit module determines the size of the measured wire resistance and the set on-resistance value, and sends a signal to the output module, and the output module outputs the comparison result.

[0026] The adjustment of the sliding resistance R3 includes:

[0027] Directly connect the P1 input terminal and the P2 input terminal, and adjust the linkage switch to the zero resistance position;

[0028] Gradually adjust the resistance of the sliding resistor R3 until the output module is adjusted to stop working.

[0029] In summary, this application at least includes the following beneficial technical effects:

[0030] 1. The present invention can realize the autonomous selection of the on-resistance threshold, and has four on-resistance detection modes of 3Ω / 5Ω / 10Ω / 20Ω, with multiple selectivity and strong versatility. The existing designs generally only have a resistance range of 20Ω.

[0031] 2. The invention has sensitive conduction detection, and directly compares and judges the on-off status of the wiring harness through the comparison circuit, and the result output is less than 1s. The existing design generally has a measurement time of 5s to 8s.

[0032] 3. Compared with the traditional digital multimeter for judging the resistance of the wiring harness, the present invention omits the function of numerical display, and the detection result is output immediately, which is concise and efficient.

[0033] 4. The present invention frees the human eye and eliminates the need for number recognition and judgment. It automatically provides feedback and prompts the result through the integration of sound and light, without the need to judge after displaying the numerical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the conduction detector module;

[0035] Figure 2 This is a schematic diagram of the working principle of the continuity detector;

[0036] Figure 3 This is the circuit structure schematic diagram of the continuity detector;

[0037] Figure 4 A simplified schematic diagram of a continuity detector. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0039] The present invention is described by taking resistance determination as an example.

[0040] The present application embodiment discloses a universal wiring harness continuity tester, such as Figure 1 and Figure 2 As shown, it includes a power module, an input module, a threshold selection module, a comparison circuit module, and an output module. For details, see Figure 1 .

[0041] The power module is mainly composed of a rechargeable lithium battery and provides power for the input module, the threshold selection module, the comparison circuit module, and the output module.

[0042] The input module is mainly composed of metal terminals, which provide connection ports for the wiring harness under test and realize the connection between the positive and negative terminals and the wires under test through the test leads.

[0043] The threshold selection module provides four resistance conduction modes: 3Ω / 5Ω / 10Ω / 20Ω. Different resistance detection ranges can be set through the linkage switch. When the linkage switch points to a certain resistance mode, the corresponding LED light will light up.

[0044] The comparison circuit module detects and compares the resistance of the measured wire and the voltage of the internal voltage divider resistor through the hardware circuit function design. First, the resistance of the measured wire is measured. When the resistance of the measured wire is small, the voltage of the internal voltage divider resistor becomes larger, and the voltage of the measured wire resistance becomes smaller. When the resistance of the wire is large, the voltage of the internal voltage divider resistor becomes smaller, and the voltage of the measured wire resistance becomes larger. Then, the internal circuit function is used to distinguish the wire resistance from the set resistance value, and then a signal is sent to the output module.

[0045] The output module outputs the detection results through the acousto-optic device.

[0046] The power module, input module, threshold selection module, comparison circuit module and output module are embedded and installed on a special housing to form a universal wiring harness continuity tester. When the wiring harness continuity tester is working, first turn on the power switch, then turn the linkage switch on the threshold selection module, set the resistance detection range of the on-resistance (one of the resistance thresholds 3Ω / 5Ω / 10Ω / 20Ω), use two test pens (one end of the test pen is connected to the positive and negative terminals of the input module, and the other end is connected to the two ends of the measured wire) to connect the wire and the input module, and accurately judge the resistance of the measured wire and the set on-resistance through the comparison circuit module, and send a signal to the output module's LED light and buzzer and other sound and light devices to feedback the test results. When the external wire resistance is less than the set resistance, the output module lights up the LED light, accompanied by a buzzer, indicating that the test is passed; when the external wire resistance is greater than the set resistance, the output module has no response, indicating that the test fails.

[0047] like Figure 3 and Figure 4 As shown, specifically, the output voltage of the power module is VCC.

[0048] The threshold selection module includes a first main circuit, one end of the first main circuit is connected to the output end of the power module, and the other end is connected to the linkage switch. The first main circuit is connected with a resistor R2 and a sliding resistor R3, and the sliding resistor R3 is connected in parallel with a resistor R4. The other end of the first main circuit is connected with a linkage switch, and the linkage switch has six gears, and the plurality of gears are respectively neutral, zero-electricity gear, resistor R5 gear, resistor R6 gear, resistor R7 gear and resistor R8 gear, that is, the linkage switch includes a neutral contact, a zero-electricity gear contact, a resistor R5 gear contact, and a resistor R6 gear contact. , resistor R7 contact and resistor R8 contact, zero-resistance contact is connected to the first branch, resistor R5 contact is connected to the second branch, resistor R6 contact is connected to the third branch, resistor R7 contact is connected to the fourth branch, resistor R8 contact is connected to the fifth branch, the other ends of the first branch, the second branch, the third branch, the fourth branch and the fifth branch are connected to the first main connection, the other end of the first main connection is connected to the input module, resistor R9 is provided on the first main connection, and the resistance value of resistor R9 is equal to that of resistor R2. No resistor is connected to the first branch, corresponding to the zero-resistance block; resistor R5 is connected to the second branch, resistor R6 is connected to the third branch, resistor R7 is connected to the fourth branch, and resistor R8 is connected to the fifth branch; resistor R5 is 3Ω, resistor R6 is 5Ω, resistor R7 is 10Ω, and resistor R8 is 20Ω.

[0049] The linkage switch is connected to a second switch, which also has six gears. The linkage switch and the second switch are linked; the six gears of the second switch correspond to neutral (no light), LED light D4 on, LED light D5 on, LED light D6 on, LED light D7 on, and LED light D8 on. The six gears of the second switch correspond one by one to the six gears of the linkage switch.

[0050] The input module includes two input terminals, which are respectively a P1 input terminal and a P2 input terminal. The P1 connection terminal is connected to the first main connection path, the P2 input terminal is connected to the output main path, and the other end of the output main path is grounded.

[0051] The comparison circuit module includes a second main path, one end of the second main path is connected to the output end of the power module, and the other end is connected to the output module; a first measuring wire and a second measuring wire are sequentially connected in parallel between the second main path and the output main path, a resistor R10 and a resistor R11 are provided on the first measuring wire, the resistance values ​​of the resistor R10 and the resistor R11 are equal, and both are 10kΩ in this embodiment, the first measuring wire is connected to a first positive input wire between the resistor R10 and the resistor R11, the other end of the first positive input wire is connected to the positive input end of the first comparator, a first negative input wire is connected to the first main connection path, the other end of the first negative input wire is connected to the negative input end of the first comparator, and the first comparator is connected to a first output line; the first comparator obtains a first output result according to the voltages of the first positive input wire and the first negative input wire; the connection point of the first negative input wire and the first main connection path, the resistor R9 and the P1 input end are sequentially distributed on the first main connection path. The second measuring wire is connected with a resistor R14 and a resistor R15, the resistance values ​​of the resistor R14 and the resistor R15 are equal, the second measuring wire is connected with a second positive input wire between the resistor R14 and the resistor R15, the second positive input wire is connected to the positive input terminal of the second comparator, the first output wire is connected to the negative input terminal of the second comparator, and the second comparator is connected with a second output wire; the second comparator obtains a second output result according to the first output result of the first comparator and the voltage of the second positive input wire; the second output wire is connected to the output module.

[0052] The first output line is also connected to the negative input terminals of the third comparator and the fourth comparator, the second positive input wire is also connected to the positive input terminals of the third comparator and the fourth comparator, the third comparator is connected to the third output line, the fourth comparator is connected to the fourth output line, the third output line and the ground output line are connected to the total output line, a resistor R16 is provided on the total output line, and the total output line is connected to the second main line.

[0053] A first voltage stabilizing line is connected between the first main line and the first output line, and a resistor R13 is arranged on the first voltage stabilizing line, and the resistance value of the resistor R13 is equal to that of the resistor R10. A second voltage stabilizing line is connected between the first measuring wire and the first voltage stabilizing line, and a resistor R12 is arranged on the second voltage stabilizing line. The resistor R13 is a pull-up resistor at the output end of the first comparator, which ensures that the comparator normally outputs a high level, and at the same time protects the circuit from being short-circuited to prevent the device from being burned.

[0054] Since the resistance values ​​of resistors R10 and R11 are equal, the positive input terminal of the first comparator is 1 / 2VCC. For the first comparator, when the voltage of the positive input terminal is higher than the negative input terminal, the output of the first comparator is high level; when the voltage of the positive input terminal is lower than the negative input terminal, the output of the first comparator is low level.

[0055] A detection method of a universal wiring harness continuity tester, comprising:

[0056] The P1 input terminal and the P2 input terminal are connected by two test leads respectively. Due to different measurement environments, the actual test lead types vary in size. Generally, the resistance of the test lead itself is (1~1.5Ω), so it is necessary to adjust the sliding resistor and adjust the circuit to the initial state. At this time, the internal resistance and the external resistance are slightly smaller.

[0057] Adjust the sliding resistor R3, specifically including: in the initial state (the P1 input terminal and the P2 input terminal are connected by two test leads, and the linkage switch is adjusted to the zero resistance position), adjust the resistance value of the sliding resistor R3 until the output module is adjusted to just stop working (that is, the LED light and the buzzer are adjusted to not light up and not sound). At this time, the voltage at the negative input terminal of the first comparator is greater than the voltage at the positive input terminal, and the output is a low level (the low level is almost 0); the output voltage of the first comparator is used as the negative input terminal of the second comparator, and the voltage at the negative input terminal of the second comparator is less than the voltage at the positive input terminal, and the output is a high level (basically equal to VCC); the output module (LED light and buzzer) basically does not work;

[0058] Set the gear position to 3Ω through the linkage switch;

[0059] Connect the measured wire to the input module through two test leads (one end of the test lead is connected to the P1 / P2 terminal of the input module, and the other end is connected to both ends of the measured wire); if the resistance of the measured wire (external measured resistance) is greater than 3Ω, the voltage at the negative input terminal of the first comparator becomes larger, but still greater than the positive input terminal, and the output is low level; the output voltage of the first comparator is used as the negative input terminal of the second comparator, and the voltage at the negative input terminal of the second comparator is less than the voltage at the positive input terminal, and the output is high level; the output module does not work;

[0060] If the resistance of the measured wire (external measurement resistance) is less than 3Ω, the voltage at the negative input terminal of the first comparator becomes smaller, the voltage at the positive input terminal of the first comparator is greater than the voltage at the negative input terminal, and a high level is output; the output voltage of the first comparator is used as the negative input terminal of the second comparator, the voltage at the negative input terminal of the second comparator is greater than the voltage at the positive input terminal, a low level is output, and the output module works.

[0061] The output module includes a display path 1 and a display path 2 connected in parallel, wherein the display path 1 is provided with an LED light, and the display path 2 is provided with a buzzer. Both ends of the display path 1 and the display path 2 are respectively connected to the second main path and the second output line connected to the second comparator.

[0062] The present invention will be described below in conjunction with the accompanying drawings.

[0063] like Figure 2As shown, first turn on the power switch of the detector, then rotate the linkage switch to set the on-resistance to 3Ω, and the corresponding setting module indicator lights up, indicating that the setting is successful. Then connect the two ends of the tested wire to the detector through the test leads. If the wire detection resistance value is less than 3Ω, the detector buzzer sounds and the LED light lights up. If the wire detection resistance value is greater than 3Ω, the detector has no response. The test results are responded immediately, without waiting.

[0064] The resistance threshold mode can be set independently according to the needs.

[0065] The universal wiring harness continuity tester includes a power module, an input module, a threshold selection module, a comparison circuit module, an output module, etc., which are all involved in existing inventions or are ready-made products and can be used as components or parts of the present invention.

[0066] Compared with existing solutions, this invention has a wide detection mode, fast detection speed, and significant improvement in detection efficiency indicators. It also has mature technology, low cost, and is easy to implement.

[0067] The contents not described in detail in this application specification belong to the common knowledge of those skilled in the art.

[0068] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A universal wiring harness continuity tester, characterized in that: It includes a power supply module, an input module, a threshold selection module, a comparison circuit module and an output module. A power module, which supplies power to the input module, the threshold selection module, the comparison circuit module and the output module; An input module provides a connection port for the wiring harness under test, and is connected to the wire under test through the connection port, so that the wire under test is connected to the threshold selection module; A threshold selection module, used to set the on-resistance value; The comparison circuit module compares the resistance of the measured wire with the set on-resistance value according to the set on-resistance value and the resistance of the measured wire, obtains a comparison result, and outputs the comparison result to the output module; The output module obtains the comparison result of the comparison circuit module and outputs the comparison result.

2. A universal wire harness continuity tester according to claim 1, characterized in that: The threshold selection module includes a resistance adjustment module, a linkage switch and a plurality of resistors with different resistance values, the resistance adjustment module is connected to the first main road, one end of the first main road is connected to the output end of the power module, and the other end is connected to the linkage switch, the linkage switch includes a plurality of gear contacts, the gear contacts include a neutral contact and a plurality of electric block contacts, each electric block contact is connected to the first main connection road through a branch, and the other end of the first main connection road is connected to the input module; each branch road is provided with a resistor, and the resistance values ​​of the resistors connected to different branches are different; The input module includes a P1 input terminal and a P2 input terminal, the P1 connection terminal is connected to the first main connection path, and the P2 input terminal is grounded through the output main path; The comparison circuit module includes a first comparator and a second comparator. The first main connection path is connected to the negative input terminal of the first comparator through a first negative input wire. The output terminal of the power supply module is also connected to the second main path. The other end of the second main path is connected to the output module. The first measuring wire and the second measuring wire are sequentially connected in parallel between the second main path and the output main path. The first measuring wire is provided with a resistor R10 and a resistor R11. The resistance values ​​of the resistor R10 and the resistor R11 are equal. The first measuring wire is connected to a first positive input wire between the resistor R10 and the resistor R11. The first positive input wire is connected to the positive input terminal of the first comparator. The first comparator obtains a first output result according to the voltage of the first positive input wire and the first negative input wire; the second measuring wire is connected to a resistor R14 and a resistor R15, the resistance values ​​of the resistor R14 and the resistor R15 are equal, the second measuring wire is connected to a second positive input wire between the resistor R14 and the resistor R15, the second positive input wire is connected to the positive input terminal of the second comparator, the first output wire is connected to the negative input terminal of the second comparator, and the second comparator is connected to the second output wire; the second comparator obtains a second output result according to the first output result of the first comparator and the voltage of the second positive input wire; The second output line is connected to the output module.

3. A universal wire harness continuity tester according to claim 2, characterized in that: The resistance adjustment module includes a sliding resistor R3 and a resistor R4, and the sliding resistor R3 and the resistor R4 are connected to the first main circuit in parallel.

4. A universal wire harness continuity tester according to claim 2, characterized in that: A resistor R9 is provided on the first main connection circuit, and a resistor R2 is connected to the first main circuit. The resistance values ​​of the resistor R9 and the resistor R2 are equal.

5. A universal wire harness continuity tester according to claim 2, characterized in that: The output module comprises a display path one and a display path two which are connected in parallel, wherein the display path one is provided with an LED lamp, and the display path two is provided with a buzzer.

6. A universal wire harness continuity tester according to claim 2, characterized in that: A first voltage stabilizing line is connected between the first main line and the first output line, and a resistor R13 is arranged on the first voltage stabilizing line. A second voltage stabilizing line is connected between the first measuring wire and the first voltage stabilizing line, and a resistor R12 is arranged on the second voltage stabilizing line.

7. A universal wire harness continuity tester according to claim 1, characterized in that: It also includes a shell, and a power supply module, an input module, a threshold selection module, a comparison circuit module and an output module are all embedded and installed on the shell.

8. A detection method of a universal wiring harness continuity detector according to any one of claims 1 to 7, characterized in that: include: Start the power module; Adjust the sliding resistor R3; The on-resistance value is set by a threshold selection module; One end of the two test leads is connected to the connection input module, and the other end is connected to the two ends of the measured wire; the comparison circuit module determines the size of the measured wire resistance and the set on-resistance value, and sends a signal to the output module, and the output module outputs the comparison result.

9. The detection method of the universal wiring harness continuity detector according to claim 8, characterized in that: The adjustment of the sliding resistor R3 includes: Directly connect the P1 input terminal and the P2 input terminal, and adjust the linkage switch to the zero resistance position; Gradually adjust the resistance of the sliding resistor R3 until the output module is adjusted to stop working.

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