A device and detection apparatus for cable continuity detection and counting

Abstract

The utility model discloses a device and detection equipment for cable on-off detection and counting, design electronic technical field, the first input of first comparison unit connects resistance R5's first end, the second input of first comparison unit connects the first USB port among double -deck USB, the first end of resistance R12 is connected among the second USB port in double -deck USB, the second end of resistance R5 and the second end of resistance R12 ground, the first USB port and second USB port connect corresponding detection end, the output of first comparison unit connects the control end of first switch, the input of first switch connects the output of counting unit and the first power supply pin of double -deck USB, and the input of counting unit and the second power supply pin of double -deck USB connect power supply output end. In this way, the number of the cable that is turned on in the multiple cables of this test is counted conveniently, and the problem of human counting mistake is reduced.

Description

Technical Field

[0001] This utility model relates to the field of electronic technology, and in particular to a device and testing equipment for detecting and counting cable continuity. Background Technology

[0002] Multimeters are widely used in industrial production, circuit repair and other fields to detect the continuity of wires. However, when a large number of wire harnesses need to be counted for continuity, current multimeters lack wire harness detection and counting functions, and often rely on manual counting, which is prone to counting errors. Utility Model Content

[0003] To address the aforementioned issues, this invention provides a device and testing equipment for detecting and counting cable continuity, thereby enabling the detection and counting of cable continuity.

[0004] The present invention discloses the following technical solutions:

[0005] In a first aspect, this application provides a device for detecting and counting cable continuity, including a housing, and a power supply circuit, a first comparison unit, a first switch, a counting unit, and a dual-layer USB, all installed within the housing.

[0006] The first input terminal of the first comparison unit is connected to the first terminal of resistor R5, the second input terminal of the first comparison unit is connected to the signal pin of the first USB port in the dual-layer USB, the signal pin of the second USB port in the dual-layer USB is connected to the first terminal of resistor R12, the second terminals of resistor R5 and resistor R12 are grounded, and the first USB port and the second USB port are connected to the corresponding detection terminals.

[0007] The first input terminal and the second input terminal are respectively connected to the power supply output terminal of the power supply circuit through corresponding resistors. The output terminal of the first comparison unit is connected to the control terminal of the first switch. The input terminal of the first switch is connected to the output terminal of the counting unit and the first power supply pin of the dual-layer USB. The input terminal of the counting unit and the second power supply pin of the dual-layer USB are connected to the power supply output terminal.

[0008] Optionally, the detection end includes a first probe and a second probe;

[0009] The first probe is connected to the first USB port via a first extension cable, and the second probe is connected to the second USB port.

[0010] Optionally, the first probe includes a probe tip, a light-emitting diode (LED), and a resistor R17. The positive terminal of the LED is connected to the power supply pin of the first USB port, the negative terminal of the LED is connected to the first end of the resistor R17, the second end of the resistor R17 is connected to the ground pin of the first USB port, and the probe tip is connected to the signal pin of the first USB port.

[0011] Optionally, the device further includes a buzzer and a self-locking button K2;

[0012] The positive terminal of the buzzer is connected to the first terminal of the self-locking button K2, the second terminal of the self-locking button K2 is connected to the power input terminal of the power supply circuit, and the negative terminal of the buzzer is connected to the input terminal of the first switch.

[0013] The housing is provided with a sound hole corresponding to the playback end of the buzzer, and the housing is provided with a second through hole corresponding to the self-locking button K2.

[0014] Optionally, an adjustable resistor R10 may also be included;

[0015] The negative terminal of the buzzer is connected to the first terminal of the adjustable resistor R10, and the second terminal of the adjustable resistor R10 is connected to the input terminal of the first switch.

[0016] The housing is equipped with a volume control button corresponding to the adjustment terminal of the adjustable resistor R10.

[0017] Optionally, the detection end may further include a third probe and a fourth probe;

[0018] The signal pin corresponding to the first USB port in the dual-layer USB is connected to the first COM port, and the first COM port is connected to the third probe through the first external lead.

[0019] The signal pin corresponding to the second USB port in the dual-layer USB is connected to the second COM port, and the second COM port is connected to the fourth probe through the second external lead.

[0020] The outer casing is provided with corresponding first mounting holes for the first COM port and the second COM port respectively; the outer casing is provided with corresponding second mounting holes for the first USB port and the second USB port respectively.

[0021] Optionally, the counting unit further includes a self-locking button K3, a self-reset button K4, and a digital tube module. The first end of the self-locking button K3 is connected to the power output terminal of the power supply circuit, the second end of the self-locking button K3 is connected to the positive terminal of the digital tube module, the negative terminal of the digital tube module is connected to the input terminal of the first switch, and the self-reset button K4 is connected to the reset pin of the digital tube module.

[0022] The housing has a transparent window corresponding to the digital display screen of the digital tube module, a third through hole corresponding to the self-locking button K3, and a fourth through hole corresponding to the self-reset button K4.

[0023] Optionally, the power supply circuit includes a power supply, a second comparison unit, a self-locking button K1, a second switch, and a third switch.

[0024] The first input terminal of the second comparator unit is connected to the first node between the negative terminal of diode D1 and the first terminal of resistor R14; the second input terminal of the second comparator unit is connected to the second node between the second terminal of resistor R16 and the first terminal of resistor R15; the third pin of the normally open contact of the self-locking button K1 is connected to the first node; the fourth pin of the normally open contact of the self-locking button K1 is connected to the first terminal of resistor R16; the first pin of the common terminal of the self-locking button K1 is connected to the positive terminal of the power supply; and the second pin of the common terminal is connected to the positive terminal of capacitor C1.

[0025] The output terminal of the second comparison unit is connected to the first terminal of resistor R19, the second terminal of resistor R19 is connected to the control terminal of the second switch, the input terminal of the second switch is connected to the second terminal of resistor R18, the first terminal of resistor R18 is connected to the control terminal of the third switch, the input terminal and the control terminal of the third switch are connected to resistor R17, the input terminal of the third switch is connected to the first terminal of resistor R16, the output terminal of the third switch, the positive terminal of diode D1 and the positive terminal of capacitor C2 are connected to the third node, and the third node is the power supply output terminal of the power supply circuit.

[0026] The output terminal of the second switch is connected to the positive terminal of diode D2. The negative terminal of the power supply, the negative terminal of capacitor C1, the negative terminal of capacitor C2, the second terminal of resistor R14, the second terminal of resistor R15, and the negative terminal of diode D2 are all connected to ground.

[0027] Optionally, an indicator light is also included, wherein the positive terminal of the indicator light is connected to the second terminal of resistor R13, the first terminal of resistor R13 is connected to the power supply output terminal of the power supply circuit, and the negative terminal of the indicator light is connected to ground.

[0028] The outer casing has a first through hole corresponding to the self-locking button K1, and the outer casing has a fifth through hole corresponding to the indicator light.

[0029] Secondly, this application also provides a testing device, including the apparatus for cable continuity detection and counting described in any one of the above claims.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] This utility model provides a device and testing equipment for cable continuity detection and counting. The first input terminal of the first comparison unit is connected to the first terminal of resistor R5, and the second input terminal of the first comparison unit is connected to the first USB port of the dual-layer USB. The second USB port of the dual-layer USB is connected to the first terminal of resistor R12. The second terminals of resistor R5 and resistor R12 are grounded. The first USB port and the second USB port are connected to corresponding detection terminals. The output terminal of the first comparison unit is connected to the control terminal of the first switch. The input terminal of the first switch is connected to the output terminal of the counting unit and the first power supply pin of the dual-layer USB. The input terminal of the counting unit and the second power supply pin of the dual-layer USB are connected to the power supply output terminal. Based on the detection end, the first USB port and the second USB port are respectively connected to the two ends of the cable under test. When the cable under test is conductive, due to the preset resistance difference between resistors R5 and R12, the first comparison unit compares the voltage at the first input terminal to be greater than the voltage at the second input terminal, thereby controlling the first switch to turn on, which in turn causes the counting unit to perform a count. In this way, multiple cables under test can be tested in sequence to understand the conductivity of the cables under test and to facilitate the counting of the number of conductive cables among the multiple cables tested, reducing the problem of human counting errors. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A circuit diagram of a device for detecting and counting cable continuity is provided for a specific embodiment of this utility model;

[0034] Figure 2 A schematic diagram of the circuit structure of the first probe is provided for a specific embodiment of this utility model;

[0035] Figure 3 A schematic diagram of a housing and device mounting structure provided for a specific embodiment of this utility model;

[0036] Figure 4 A schematic diagram of the external structure of a device provided for a specific embodiment of this utility model;

[0037] Figure 5 This is a schematic diagram of the connection structure between a device and a probe, provided for a specific embodiment of this utility model.

[0038] Explanation of Figure Numbers

[0039] 1-First probe; 2-Second probe; 3-Sound hole; 4-Second via hole; 5-Third probe; 6-Fourth probe; 7-First mounting hole; 8-Second mounting hole; 9-Transparent window; 10-Third via hole; 11-Fourth via hole; 12-First via hole; 13-Fifth via hole; 14-Volume button. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] See Figure 1 The diagram shows a circuit structure of a device for detecting and counting cable continuity. The device includes a housing, and a power supply circuit, a first comparison unit, a first switch, a counting unit, and a dual-layer USB connector installed within the housing.

[0042] The first input terminal of the first comparison unit is connected to the first terminal of resistor R5, the second input terminal of the first comparison unit is connected to the signal pin of the first USB port in the dual-layer USB, the signal pin of the second USB port in the dual-layer USB is connected to the first terminal of resistor R12, the second terminals of resistor R5 and resistor R12 are grounded, and the first USB port and the second USB port are connected to the corresponding detection terminals.

[0043] The first input terminal and the second input terminal of the first comparison unit are respectively connected to the power supply output terminal of the power supply circuit through corresponding resistors. The output terminal of the first comparison unit is connected to the control terminal of the first switch. The input terminal of the first switch is connected to the output terminal of the counting unit and the first power supply pin of the dual-layer USB. The input terminal of the counting unit and the second power supply pin of the dual-layer USB are connected to the power supply output terminal.

[0044] The first switch mentioned above is a semiconductor device capable of on / off control, such as a transistor.

[0045] The aforementioned counting unit may include a digital tube module, which increments the count by one each time it is powered on.

[0046] The aforementioned dual-layer USB can be a dual-layer full-coverage USB, which may include two USB ports (the first USB port and the second USB port mentioned above). Each of the two USB ports is connected to one of a pair of detection terminals. This pair of detection terminals is connected to both ends of the cable to detect whether the cable is conducting or disconnected.

[0047] See Figure 1 The first USB port and the second USB port are connected to the two ends of the cable under test through the detection end. The first input terminal of the first comparison unit is connected to the first end of resistor R5 (node ​​one); the second input terminal of the first comparison unit is connected to the first end of resistor R12 (node ​​two). When the cable under test is conductive, due to the preset resistance difference between resistor R5 and resistor R12, the first comparison unit compares the voltage between node one and node two. When the voltage of the first node is greater than the voltage of the second node, a high voltage is output at the output terminal of the first comparison unit, thereby controlling the first switch to conduct, and then causing the counting unit to perform a count. In this way, multiple cables under test can be tested in sequence to understand the conductivity of the cables under test and to facilitate the counting of the number of conductive cables in the multiple cables tested, reducing the problem of human counting errors.

[0048] Optional, such as Figure 1 The first input terminal 1IN+ and the second input terminal 1IN- of the first comparison unit are respectively connected to the power output terminal of the power supply circuit through corresponding resistors. Specifically, the first input terminal 1IN+ can be connected to the power output terminal of the power supply circuit after being connected in series with resistors R3 and R1, and the first input terminal 1IN+ can be connected to the power output terminal of the power supply circuit after being connected in series with resistors R4 and R2. The end where resistors R3 and R1 are connected is connected to the end where resistors R4 and R2 are connected. The preset resistance difference between resistors R5 and R12 can be 50 ohms. Optionally, resistors R5 and R12 can be adjusted using variable resistors.

[0049] Optional, such as Figure 1 A resistor R9 can be connected between the output terminal of the first comparator and the control terminal of the first switch. One end of resistor R9 connected to the output terminal of the first comparator can be connected to a resistor group (such as...). Figure 1 The resistor group may include three resistors (R6, R7 and R8) connected in parallel at its first end, and the second end of the resistor group is connected to the power supply output terminal of the power supply unit.

[0050] Based on the above embodiments, this application also proposes that the detection end includes a first probe 1 and a second probe 2.

[0051] Optionally, the first probe is connected to the first USB port via a first extension cable, and / or the second probe is connected to the second USB port via a second extension cable.

[0052] Optionally, the first and second extension cables mentioned above can be made of three-core silicone soft copper wire. The length can be selected as 2 meters, but can also be set according to actual length requirements.

[0053] The above-mentioned method of connecting the USB port to the test probes via an extension cable is suitable for situations where the two ends of the cable under test are far apart, such as large equipment. Furthermore, an extension cable can be configured for any one or both probes in a pair of test terminals as needed to address situations where the two ends of the cable under test are at different distances.

[0054] Further, see Figure 2 The diagram shows a circuit structure of a first probe, which includes a probe tip, a light-emitting diode (LED) VD2, and a resistor R17. The positive terminal of the LED is connected to the power supply pin of the first USB port (e.g., ...). Figure 2 The negative terminal of the LED is connected to the first end of the resistor R17, and the second end of the resistor R17 is connected to the ground pin of the first USB port (e.g., the VCC pin). Figure 2 The probe tip is connected to the signal pin of the first USB port (GND pin). Similarly, the second probe can adopt the same circuit connection structure as the first probe.

[0055] The first and second probes are connected to the two ends of the cable under test, respectively. When the cable under test is conductive, the probe equipped with an LED will light up. In this way, when the two ends of the cable under test are far apart, and the continuity indication information on the device (such as the count of the counting unit on the device) is inconvenient to see from a distance, the continuity of the cable under test can be determined by the lighting of the probes, thus improving the convenience of operation.

[0056] Based on the above embodiments, see Figure 1 as well as Figure 3 The diagram shows a mounting structure for a housing and a device. Figure 4 The diagram shows the external structure of a device. The device of this application further includes a buzzer H1 and a self-locking button K2; the positive terminal of the buzzer H1 is connected to the first end of the self-locking button K2, the second end of the self-locking button K2 is connected to the power input terminal of the power supply circuit, and the negative terminal of the buzzer H1 is connected to the input terminal of the first switch; the housing is provided with a sound hole 3 corresponding to the playback end of the buzzer H1, and the housing is provided with a second through hole 4 corresponding to the self-locking button K2.

[0057] The buzzer H1, configured as described above, allows users to easily determine the continuity of the cable under test by sound. Furthermore, the negative terminal of the buzzer is connected to the first end of the adjustable resistor R10, and the second end of the adjustable resistor R10 is connected to the input terminal of the first switch. A volume button 14 is configured on the housing corresponding to the adjustment terminal of the adjustable resistor R10. This avoids situations where the user cannot hear the buzzer's prompt in excessively noisy environments. It also avoids situations where the buzzer's prompt is too loud in relatively quiet environments. The buzzer's volume can be adjusted reasonably according to the noise level of the operating environment, improving the user's comfort.

[0058] Based on the above embodiments, see Figure 5 The diagram shows a connection structure between a device and test leads. The detection end further includes a third test lead 5 and a fourth test lead 6; the signal pin corresponding to the first USB port in the dual-layer USB is connected to the first COM port, and the first COM port is connected to the third test lead via a first external lead; the signal pin corresponding to the second USB port in the dual-layer USB is connected to the second COM port, and the second COM port is connected to the fourth test lead via a second external lead; the housing is provided with corresponding first mounting holes 7 for the first COM port and the second COM port respectively; the housing is provided with corresponding second mounting holes 8 for the first USB port and the second USB port respectively.

[0059] Optionally, the first COM port and the second COM port mentioned above use banana plugs.

[0060] The lengths of the first and second external leads are both shorter than the lengths of the first and second extension cables, respectively. This design is suitable for situations where the distance between the two ends of the cable under test is small, such as when testing small devices or circuit boards. The tester can connect the corresponding external leads to the first and second COM ports, and then connect the third and fourth probes to the two ends of the cable under test that are close together (here, "closer" means a distance that allows the tester to easily read the continuity indication information on the device) for testing.

[0061] Based on the above embodiments, see Figure 1 , Figure 3 and Figure 4The counting unit in this application may include a self-locking button K3, a self-reset button K4, and a digital tube module DS1. The first end of the self-locking button K3 is connected to the power output terminal of the power supply circuit, the second end of the self-locking button K3 is connected to the positive terminal of the digital tube module, the negative terminal of the digital tube module is connected to the input terminal of the first switch, and the self-reset button K4 is connected to the reset pin of the digital tube module. The housing is provided with a transparent window 9 corresponding to the digital display screen of the digital tube module, a third via 10 corresponding to the self-locking button K3, and a fourth via 11 corresponding to the self-reset button K4.

[0062] Each time the cable under test is found to be conductive, the digital display module inside the transparent window increments by one. The digital display module increments its count with each power-on cycle and saves the data upon power-off. It can display a three-digit number, with a maximum value of 999. The input and output terminals of the self-reset button K4 are connected to the reset pin of the digital display module, as shown below. Figure 1 The reset pins J1 and J2 in the module are used to clear the Schumann tube module after shorting J1 and J2 for the target duration, so that the counting can be restarted next time.

[0063] Based on the above embodiments, the device can be powered by a storage battery, and the power supply circuit can automatically shut down when the battery voltage is low or when there is a power outage. See [link to documentation]. Figure 1The power supply circuit includes a power supply, a second comparison unit, a self-locking button K1, a second switch VT2, and a third switch VT3. The first input terminal of the second comparison unit is connected to a first node between the negative terminal of diode D1 and the first terminal of resistor R14. The second input terminal of the second comparison unit is connected to a second node between the second terminal of resistor R16 and the first terminal of resistor R15. The third pin of the normally open contact of the self-locking button K1 is connected to the first node. The fourth pin of the normally open contact of the self-locking button K1 is connected to the first terminal of resistor R16. The first pin of the common terminal of the self-locking button K1 is connected to the positive terminal of the power supply, and the second pin of the common terminal is connected to the positive terminal of capacitor C1. The output terminal of the second comparison unit is connected to the first terminal of resistor R19, and the second terminal of resistor R19 is connected to... The control terminal of the second switch VT2 is connected to the second terminal of resistor R18. The first terminal of resistor R18 is connected to the control terminal of the third switch. The input terminal and control terminal of the third switch VT3 are connected to resistor R17. The input terminal of the third switch VT3 is connected to the first terminal of resistor R16. The output terminal of the third switch, the positive terminal of diode D1, and the positive terminal of capacitor C2 are connected to a third node, which is the power supply output terminal of the power supply circuit. The output terminal of the second switch VT2 is connected to the positive terminal of diode D2. The negative terminal of the power supply, the negative terminals of capacitor C1 and C2, the second terminals of resistors R14 and R15, and the negative terminal of diode D2 are all connected to ground.

[0064] Optionally, the first comparison unit and the second comparison unit mentioned above can use the same comparator, which can realize the comparison of two sets of independent voltages, such as... Figure 1 The comparator U1 includes a first input terminal 1IN+ and a second input terminal 1IN- for the first group of voltage comparison, and a corresponding output terminal 1OUT; and a first input terminal 2IN+ and a second input terminal 2IN- for the second group of voltage comparison, and a corresponding output terminal 2OUT.

[0065] When the device is powered off, the output terminal 2OUT outputs a low level, the second switch VT2 and the third switch VT3 are turned off, stopping the power supply to the subsequent detection circuit and realizing automatic shutdown.

[0066] Furthermore, the above-mentioned device may also include an indicator light VD1, the positive terminal of which is connected to the second end of a resistor R13, the first end of which is connected to the power supply output terminal of the power supply circuit, and the negative terminal of which is connected to ground.

[0067] The outer casing is provided with a first through hole 12 corresponding to the self-locking button K1, and the outer casing is provided with a fifth through hole 13 corresponding to the indicator light.

[0068] Optional, such as Figure 4 or Figure 5 The casing of this application may also be marked with relevant prompts, such as "Power" for the first via, "Buzzer" for the second via, "Digital Display" for the third via, "Reset" for the fourth via, "Indicator Light" for the fifth via, "Volume Button" for the volume buttons, "COM1" for the first COM port, "COM2" for the second COM port, and "USB" for the dual-layer USB port; the device name may also be displayed on the front of the casing, such as "Continuity Tester"; prompts may also be displayed on the front of the casing, such as "Before testing, short-circuit the test leads to confirm that the buzzer and counter display are normal!"

[0069] See Figure 1-5 Before using the above-mentioned device, visually inspect it to ensure that the device and both pairs of test leads are in good condition, and that the test lead contacts are free of rust and stains. Select a pair of test leads according to actual needs and insert them into the corresponding ports of the device.

[0070] When using the device, first press the buttons K1 (power supply), K2 (buzzer), and K3 (digital tube module). The power indicator light will illuminate. Connect the two test leads to the test contacts to check if the buzzer and digital display are normal. Of course, the tester can also adjust the buzzer volume and turn the buzzer and digital display on or off according to actual needs.

[0071] Then, connect the test leads to both ends of the cable under test. The device will beep (the count on the digital display will increment by one; if the first and second test leads are used, the LEDs on the test leads will light up), indicating that the cable under test is conductive. Test multiple cables in sequence until all cables have been tested. Record the data and turn off buttons K1, K2, and K3. Pressing button K4 for a preset time will reset the count to zero.

[0072] In addition, this application also provides a testing device, including a device for cable continuity detection and counting as described in any of the above embodiments.

[0073] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0074] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for detecting and counting cable continuity, characterized in that, Includes a housing, and a power supply circuit, a first comparison unit, a first switch, a counting unit, and a dual-layer USB, all installed within the housing. The first input terminal of the first comparison unit is connected to the first terminal of resistor R5, the second input terminal of the first comparison unit is connected to the signal pin of the first USB port in the dual-layer USB, the signal pin of the second USB port in the dual-layer USB is connected to the first terminal of resistor R12, the second terminals of resistor R5 and resistor R12 are grounded, and the first USB port and the second USB port are connected to the corresponding detection terminals. The first input terminal and the second input terminal are respectively connected to the power supply output terminal of the power supply circuit through corresponding resistors. The output terminal of the first comparison unit is connected to the control terminal of the first switch. The input terminal of the first switch is connected to the output terminal of the counting unit and the first power supply pin of the dual-layer USB. The input terminal of the counting unit and the second power supply pin of the dual-layer USB are connected to the power supply output terminal.

2. The apparatus according to claim 1, characterized in that, The detection end includes a first probe and a second probe; The first probe is connected to the first USB port via a first extension cable, and the second probe is connected to the second USB port.

3. The apparatus according to claim 2, characterized in that, The first probe includes a probe tip, a light-emitting diode (LED), and a resistor R17. The positive terminal of the LED is connected to the power supply pin of the first USB port, the negative terminal of the LED is connected to the first end of the resistor R17, the second end of the resistor R17 is connected to the ground pin of the first USB port, and the probe tip is connected to the signal pin of the first USB port.

4. The apparatus according to claim 2, characterized in that, The device also includes a buzzer and a self-locking button K2; The positive terminal of the buzzer is connected to the first terminal of the self-locking button K2, the second terminal of the self-locking button K2 is connected to the power input terminal of the power supply circuit, and the negative terminal of the buzzer is connected to the input terminal of the first switch. The housing is provided with a sound hole corresponding to the playback end of the buzzer, and the housing is provided with a second through hole corresponding to the self-locking button K2.

5. The apparatus according to claim 4, characterized in that, It also includes the adjustable resistor R10; The negative terminal of the buzzer is connected to the first terminal of the adjustable resistor R10, and the second terminal of the adjustable resistor R10 is connected to the input terminal of the first switch. The housing is equipped with a volume control button corresponding to the adjustment terminal of the adjustable resistor R10.

6. The apparatus according to claim 2, characterized in that, The detection terminal also includes a third probe and a fourth probe; The signal pin corresponding to the first USB port in the dual-layer USB is connected to the first COM port, and the first COM port is connected to the third probe through the first external lead. The signal pin corresponding to the second USB port in the dual-layer USB is connected to the second COM port, and the second COM port is connected to the fourth probe through the second external lead. The outer casing is provided with corresponding first mounting holes for the first COM port and the second COM port respectively; the outer casing is provided with corresponding second mounting holes for the first USB port and the second USB port respectively.

7. The apparatus according to claim 1, characterized in that, The counting unit also includes a self-locking button K3, a self-reset button K4, and a digital tube module. The first end of the self-locking button K3 is connected to the power output terminal of the power supply circuit, the second end of the self-locking button K3 is connected to the positive terminal of the digital tube module, the negative terminal of the digital tube module is connected to the input terminal of the first switch, and the self-reset button K4 is connected to the reset pin of the digital tube module. The housing has a transparent window corresponding to the digital display screen of the digital tube module, a third through hole corresponding to the self-locking button K3, and a fourth through hole corresponding to the self-reset button K4.

8. The apparatus according to any one of claims 1-7, characterized in that, The power supply circuit includes a power supply, a second comparison unit, a self-locking button K1, a second switch, and a third switch. The first input terminal of the second comparison unit is connected to the first node between the negative terminal of diode D1 and the first terminal of resistor R14, and the second input terminal of the second comparison unit is connected to the second node between the second terminal of resistor R16 and the first terminal of resistor R15. The third pin of the normally open contact of the self-locking button K1 is connected to the first node, the fourth pin of the normally open contact of the self-locking button K1 is connected to the first end of the resistor R16, the first pin of the common terminal of the self-locking button K1 is connected to the positive terminal of the power supply, and the second pin of the common terminal is connected to the positive terminal of the capacitor C1. The output terminal of the second comparison unit is connected to the first terminal of resistor R19, the second terminal of resistor R19 is connected to the control terminal of the second switch, the input terminal of the second switch is connected to the second terminal of resistor R18, the first terminal of resistor R18 is connected to the control terminal of the third switch, the input terminal and the control terminal of the third switch are connected to resistor R17, the input terminal of the third switch is connected to the first terminal of resistor R16, the output terminal of the third switch, the positive terminal of diode D1 and the positive terminal of capacitor C2 are connected to the third node, and the third node is the power supply output terminal of the power supply circuit. The output terminal of the second switch is connected to the positive terminal of diode D2. The negative terminal of the power supply, the negative terminal of capacitor C1, the negative terminal of capacitor C2, the second terminal of resistor R14, the second terminal of resistor R15, and the negative terminal of diode D2 are all connected to ground.

9. The apparatus according to claim 8, characterized in that, It also includes an indicator light, the positive terminal of which is connected to the second end of resistor R13, the first end of resistor R13 is connected to the power supply output terminal of the power supply circuit, and the negative terminal of the indicator light is connected to ground. The outer casing has a first through hole corresponding to the self-locking button K1, and the outer casing has a fifth through hole corresponding to the indicator light.

10. A testing device, characterized in that, The device includes any one of claims 1-9 for detecting and counting cable continuity.

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