Low-voltage electrical component power on / off detection circuit and detection device

Abstract

The utility model relates to the field of power on-off detection, disclose a kind of low-voltage electrical component power on-off electricity detection circuit and detection device.The detection circuit includes three-phase line, general switch, test loop and control loop, three-phase line connects power supply, general switch connects three-phase line, test loop is connected with general switch correspondingly, test loop connects equipment to be measured, detection equipment is set in test loop, to detect equipment to be measured;Control loop connects test loop, and control loop is provided with contactor, and the main contact of contactor is set in test loop, and the on-off control of test loop is carried out.The detection circuit is on-off to entire detection circuit by general switch, test loop detects equipment to be measured, contactor is set in control loop, by controlling contactor, reach the purpose of adjusting the on-off of test loop by the main contact of contactor, it is convenient to detect equipment to carry out surge resistance of equipment to be measured under the moment condition of the main contact disconnection.

Description

Technical Field

[0001] This utility model relates to the field of power supply continuity detection, specifically to a power supply continuity detection circuit and detection device for low-voltage electrical components. Background Technology

[0002] With the increasing prevalence of electric forklifts and pallet trucks, the number of low-voltage electrical components is growing, necessitating more sophisticated methods for durability testing. Current technologies commonly employ pointer-type instruments and manual recording, which result in significant errors. Dedicated on-off durability testing equipment is expensive, and its simulated operating conditions are inconsistent, failing to meet the requirements for testing the lifespan of electrical components during power-on operation and analyzing the surge resistance of electrical equipment. Utility Model Content

[0003] To overcome the above problems, this utility model provides a power supply on / off detection circuit for low-voltage electrical components. The detection circuit is equipped with a three-phase line connected to an external power source to ensure power supply. At the same time, a main switch is set up to control the on / off state of the entire detection circuit. A test circuit is set up to detect the device under test. A contactor is set up in the control circuit. By controlling the contactor, the on / off state of the test circuit can be controlled by adjusting the main contacts of the contactor. This allows the surge resistance capability of the device under test to be tested when the main contacts are open.

[0004] To achieve the above objectives, this utility model provides a power on / off detection circuit for low-voltage electrical components, the detection circuit comprising:

[0005] Three-phase circuit, connected to an external power source;

[0006] The main switch, with its first, third, and fifth terminals connected to the L1, L2, and L3 lines of the three-phase circuit respectively;

[0007] The test circuit has its first, second, and third ends connected to the second, fourth, and sixth ends of the main switch, respectively. The fourth, fifth, and sixth ends of the test circuit are connected to an external device under test (DUT). A detection device is installed in the test circuit to detect the DUT.

[0008] A control circuit, wherein the first and second ends of the control circuit are connected to the first and second ends of the test circuit, and the control circuit is equipped with a contactor, wherein the main contacts of the contactor are located in the test circuit to complete the on / off control of the test circuit.

[0009] Preferably, the test circuit includes:

[0010] Three first fuses, one end of each of the three first fuses being connected to the first, second and third ends of the test circuit respectively;

[0011] The main contacts are connected to the other ends of the three first fuses at their first, third, and fifth ends respectively, and to the fourth, fifth, and sixth ends respectively of the test circuit at their second, fourth, and sixth ends respectively.

[0012] Preferably, the testing device is an oscilloscope, the voltage probe of the oscilloscope is connected to the first end of the main contact, the current probe of the oscilloscope is connected to the second end of the main contact, and the voltage probe is grounded.

[0013] Preferably, the control loop includes:

[0014] Two second fuses, one end of each second fuse being connected to the first and second ends of the control circuit respectively;

[0015] A switch, one end of which is connected to the other end of a second fuse that is connected to a first end of the control circuit;

[0016] A selection switch, wherein the first and third ends of the selection switch are connected to the other end of the switch;

[0017] A normally closed relay, wherein one end of the normally closed contact of the normally closed relay is connected to the second end of the selector switch;

[0018] A first time-delay relay, one end of the first coil of the first time-delay relay is connected to the other end of the normally closed contact of the normally closed relay, the other end of the first coil of the first time-delay relay is connected to the other end of the second fuse connected to the second end of the control circuit, and one end of the first normally open contact of the first time-delay relay is connected to the other end of the switch;

[0019] The second time-delay relay has one end of its second coil connected to the other end of the first normally open contact of the first time-delay relay, the other end of its second coil connected to the other end of the first coil of the first time-delay relay, one end of its second normally open contact connected to the other end of the switch, and the other end of its second normally open contact connected to one end of the normally closed coil of the normally closed relay.

[0020] The measuring device, wherein the first contact and the second contact of the measuring device are respectively connected to the other ends of the two second fuses;

[0021] The contactor has one end of its contact coil connected to one end of the second coil of the second time delay relay, the other end of its contact coil connected to the other end of the second coil of the second time delay relay, the other end of its contact coil connected to the other end of the normally closed coil of the normally closed relay, one end of its normally open contact connected to the third contact of the meter, and the other end of its normally open contact connected to the fourth contact of the meter.

[0022] Preferably, the fifth contact of the meter is connected to the fourth terminal of the selector switch, and the sixth contact of the meter is connected to one end of the contact coil of the contactor.

[0023] Another aspect of this utility model provides a power on / off durability testing device for low-voltage electrical components, the testing device comprising:

[0024] power supply;

[0025] Three-phase circuit, connected to an external power source;

[0026] The main switch, with its first, third, and fifth terminals connected to the L1, L2, and L3 lines of the three-phase circuit respectively;

[0027] The test circuit has its first, second, and third ends connected to the second, fourth, and sixth ends of the main switch, respectively. The fourth, fifth, and sixth ends of the test circuit are connected to an external device under test (DUT). A detection device is installed in the test circuit to detect the DUT.

[0028] A control circuit, wherein the first and second ends of the control circuit are connected to the first and second ends of the test circuit, and the control circuit is equipped with a contactor, wherein the main contacts of the contactor are located in the test circuit to complete the on / off control of the test circuit.

[0029] Preferably, the test circuit includes:

[0030] Three first fuses, one end of each of the three first fuses being connected to the first, second and third ends of the test circuit respectively;

[0031] The main contacts are connected to the other ends of the three first fuses at their first, third, and fifth ends respectively, and to the fourth, fifth, and sixth ends respectively of the test circuit at their second, fourth, and sixth ends respectively.

[0032] Preferably, the testing device is an oscilloscope, the voltage probe of the oscilloscope is connected to the first end of the main contact, the current probe of the oscilloscope is connected to the second end of the main contact, and the voltage probe is grounded.

[0033] Preferably, the control loop includes:

[0034] Two second fuses, one end of each second fuse being connected to the first and second ends of the control circuit respectively;

[0035] A switch, one end of which is connected to the other end of a second fuse that is connected to a first end of the control circuit;

[0036] A selection switch, wherein the first and third ends of the selection switch are connected to the other end of the switch;

[0037] A normally closed relay, wherein one end of the normally closed contact of the normally closed relay is connected to the second end of the selector switch;

[0038] A first time-delay relay, one end of the first coil of the first time-delay relay is connected to the other end of the normally closed contact of the normally closed relay, the other end of the first coil of the first time-delay relay is connected to the other end of the second fuse connected to the second end of the control circuit, and one end of the first normally open contact of the first time-delay relay is connected to the other end of the switch;

[0039] The second time-delay relay has one end of its second coil connected to the other end of the first normally open contact of the first time-delay relay, the other end of its second coil connected to the other end of the first coil of the first time-delay relay, one end of its second normally open contact connected to the other end of the switch, and the other end of its second normally open contact connected to one end of the normally closed coil of the normally closed relay.

[0040] The measuring device, wherein the first contact and the second contact of the measuring device are respectively connected to the other ends of the two second fuses;

[0041] The contactor has one end of its contact coil connected to one end of the second coil of the second time delay relay, the other end of its contact coil connected to the other end of the second coil of the second time delay relay, the other end of its contact coil connected to the other end of the normally closed coil of the normally closed relay, one end of its normally open contact connected to the third contact of the meter, and the other end of its normally open contact connected to the fourth contact of the meter.

[0042] Preferably, the fifth contact of the meter is connected to the fourth terminal of the selector switch, and the sixth contact of the meter is connected to one end of the contact coil of the contactor.

[0043] Through the above technical solution, the detection circuit and detection device are equipped with a three-phase power supply to ensure power supply, and a main switch is set to control the on / off state of the entire detection circuit. An oscilloscope is connected in the test circuit as a detection device to test the pulse current and voltage of the device under test at the moment the main contacts close. In the control circuit, a selector switch, normally closed relays, and time-delay relays are set. When the selector switch is selected to the switch position connected to the normally closed relay, the normally closed relay, the first time-delay relay, and the second time-delay relay control the contactor after closing in stages. The opening and closing of the main contacts and normally open contacts of the contactor control the on / off state of the test circuit and the counting of the tester, respectively. The normally closed contacts and coil of the normally closed relay, in cooperation with the first time-delay relay and the second time-delay relay, achieve cyclic on / off switching to perform surge resistance durability testing of the device under test and detect its service life. When the selector switch is selected to the switch position connected to the fifth and sixth contacts of the tester, the tester sets the durability time to be verified. During the set time, the main contacts of the contactor remain closed, so that the device under test is in working state, which facilitates the detection of the power consumption and durability of the device under test. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the circuit connection of a power supply on / off detection circuit for a low-voltage electrical component according to one embodiment of the present invention;

[0045] Figure 2 This is a circuit connection diagram of a power supply on / off detection circuit for a low-voltage electrical component according to one embodiment of the present invention.

[0046] Explanation of reference numerals in the attached figures

[0047] Detailed Implementation

[0048] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0049] In this embodiment of the utility model, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used to describe the relative positional relationships of the components in relation to the directions shown in the accompanying drawings or in relation to the vertical, perpendicular, or gravitational directions.

[0050] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0051] like Figure 1 This is a circuit connection diagram of a low-voltage electrical component power on / off detection circuit according to one embodiment of the present invention. Figure 2 The diagram shown is a circuit connection schematic of a power on / off detection circuit for a low-voltage electrical component according to one embodiment of the present invention. Figure 1 , 2 The low-voltage electrical component power on / off detection circuit includes a three-phase line 1, a main switch 2, a test circuit 3, and a control circuit 4. The three-phase line 1 is connected to an external power source. The first, third, and fifth terminals of the main switch 2 are connected to the L1, L2, and L3 lines of the three-phase line 1, respectively. The first, second, and third terminals of the test circuit 3 are connected to the second, fourth, and sixth terminals of the main switch 2, respectively. The fourth, fifth, and sixth terminals of the test circuit 3 are connected to an external device under test (DUT), and a detection device is installed in the test circuit 3 to detect the DUT. The first and second terminals of the control circuit 4 are connected to the first and second terminals of the test circuit 3, and a contactor is installed in the control circuit 4. The contactor includes a main contact 413, which is located in the test circuit 3 to control the on / off state of the test circuit 3.

[0052] The testing circuit is equipped with a three-phase line connected to an external power supply to ensure power supply. A main switch is set up to control the on / off state of the entire testing circuit. A test circuit is set up to test the device under test. A contactor is set up in the control circuit. By controlling the contactor, the on / off state of the test circuit can be controlled by adjusting the main contacts of the contactor. This allows the surge resistance capability of the device under test to be tested when the main contacts are open.

[0053] exist Figure 1 , 2In this invention, considering the reasonable connection of the detection circuit 33 and ensuring its safety, in one embodiment of the present invention, the test circuit 3 includes three first fuses 37 and a main contact 413. One end of each of the three first fuses 37 is connected to the first end 31, the second end 32, and the third end 33 of the test circuit. The first end 3a, the third end 3c, and the fifth end 3e of the main contact are connected to the other end of each of the three first fuses 37. The second end 3b, the fourth end 3d, and the sixth end 3e of the main contact are connected to the fourth end 34, the fifth end 35, and the sixth end 36 of the test circuit. The first fuses 37 protect the entire detection circuit, and the main contact 413 can completely switch the device under test on and off.

[0054] exist Figure 1 , 2 In order to detect the surge resistance capability of the device under test and ensure the proper connection of the detection circuit 3, in one embodiment of this utility model, the detection device can be any of those known in the art. The detection device can be an oscilloscope 38. The voltage probe 381 of the oscilloscope 38 is connected to the first end 3a of the main contact, and the current probe 382 of the oscilloscope 38 is connected to the second end 3b of the main contact. The voltage probe 381 is grounded, so that the pulse current and voltage of the device under test can be recorded at the moment when the main contact 413 is turned on and off.

[0055] exist Figure 1 , 2In order to realize the on / off control of the main contact 413 by the control circuit 4, and to realize the cyclic testing of the device under test and the recording of the number of cycles; in one embodiment of this utility model, the connection method of the control circuit is a connection method known to those skilled in the art. The control circuit 4 includes two second fuses 403, a switch 404, a selector switch 405, a normally closed relay (not shown in the figure), a first time delay relay (not shown in the figure), a second time delay relay (not shown in the figure), a meter 415, and a contactor (not shown in the figure). The normally closed relay includes a normally closed contact 406 and a normally closed coil 407. The first time delay relay includes a first coil 408 and a first normally open contact 409. The time relay includes a second coil 410 and a second normally open contact 411; the contactor includes a main contact 413, a normally open contact 414, and a contact coil 412; the meter 415 includes multiple contacts; one end of each of the two second fuses 403 is connected to the first terminal 401 and the second terminal 402 of the control circuit, respectively; one end of the switch 404 is connected to the other end of the second fuses 403 connected to the first terminal 401 of the control circuit; the first terminal 4051 and the third terminal 4053 of the selector switch are connected to the other end of the switch 404; one end of the normally closed contact 406 of the normally closed relay is connected to the second terminal 4052 of the selector switch; and the first coil 408 of the first time delay relay... One end of the first normally closed contact 406 of the first time delay relay is connected to the other end of the first coil 408 of the first time delay relay, and the other end of the second fuse 403 connected to the second terminal 402 of the control circuit is connected to the other end of the switch 404. One end of the first normally open contact 409 of the first time delay relay is connected to the other end of the switch 404. One end of the second coil 410 of the second time delay relay is connected to the other end of the first normally open contact 409 of the first time delay relay, and the other end of the second coil 410 of the second time delay relay is connected to the other end of the first coil 408 of the first time delay relay. One end of the second normally open contact 411 of the second time delay relay is connected to the other end of the switch 404. The other end of the closed contact 411 is connected to one end of the normally closed coil 407 of the normally closed relay. The first contact 5a and the second contact 5b of the meter are connected to the other ends of the two second fuses 403 respectively. One end of the contact coil 412 of the contactor is connected to one end of the second coil 410 of the second time delay relay. The other end of the contact coil 412 of the contactor is connected to the other end of the second coil 410 of the second time delay relay. The other end of the contact coil 412 of the contactor is connected to the other end of the normally closed coil 407 of the normally closed relay. One end of the normally open contact 414 of the contactor is connected to the third contact 5c of the meter. The other end of the normally open contact 414 of the contactor is connected to the fourth contact 5d of the meter.

[0056] When the control circuit 4 needs to cyclically switch the main contact 413 on and off to record the number of cycles and meet the surge resistance test requirements, when the selector switch 405 selects the switch position connected to the normally closed relay, the first terminal 4051 and the second terminal 4052 of the selector switch close, the normally closed contact 406 is closed, the first coil 408 is energized, and after a delay, the first normally open contact 409 closes. At this time, the second coil 410 and the contact coil 412 are energized, the main contact 413 and the normally open contact 414 close simultaneously, and the measuring instrument 415 is activated because of the normally open contact 414. The device is connected to the measuring instrument 415 to record the number of on / off cycles. When the main contact 413 is switched on or off, the detection device performs the detection. After a certain delay, the second normally open contact 411 of the second time delay relay closes. At this time, the normally closed coil 407 is turned on, the normally closed contact 406 is opened, the first coil 408 is turned off, the first normally open contact 409 is opened, the second coil 410 and the contact coil 412 are turned off, the main contact 413 and the normally open contact 414 are turned off, the second normally open contact 411 is turned off, and after the normally closed coil 407 is turned off, the normally closed contact 407 is closed, and the cycle is repeated to realize the cyclic on / off detection.

[0057] exist Figure 1 , 2 In this invention, considering the durability test of the device under test, its service life and power are tested. In one embodiment of this invention, the connection method of the control circuit is a connection method known in the art. The fifth contact 5e of the tester is connected to the fourth terminal 4054 of the selector switch, and the sixth contact 5f of the tester is connected to one end of the contact coil 412 of the contactor. At a preset time, when the selector switch 405 selects the switch position connected to the fifth contact 5e of the tester, the third terminal 4053 and the fourth terminal 4054 of the selector switch close. The fifth contact 5e and the sixth contact 5f of the tester are in a closed state, the tester outputs a timer, the second coil 410 and the contact coil 412 are connected, the main contact 413 and the normally open contact 414 are closed, the second time delay relay delays for a period of time, the second normally open contact 411 closes, the normally closed coil 407 is connected, and the normally closed contact 406 is opened. The rest of the circuit is not connected and will not affect the durability test. At this time, the device under test is in working state, and a power meter can be connected to the three-phase line to detect the power consumption of the device under test within the time set by the tester 415, detect its usage, and verify the durability time to be tested. When the preset time ends, the fifth contact and the sixth contact open, and the circuit is broken.

[0058] Another aspect of this utility model provides a power supply on / off detection device for low-voltage electrical components. The detection device includes a power supply, a three-phase line 1, a main switch 2, a test circuit 3, and a control circuit 4. The three-phase line 1 is connected to the power supply (not shown in the figure). The first, third, and fifth terminals of the main switch 2 are connected to the L1, L2, and L3 lines of the three-phase line 1, respectively. The first, second, and third terminals of the test circuit 3 are connected to the second, fourth, and sixth terminals of the main switch 2, respectively. The fourth, fifth, and sixth terminals of the test circuit 3 are connected to an external device under test (DUT), and a detection device is installed in the test circuit 3 to detect the DUT. The first and second terminals of the control circuit 4 are connected to the first and second terminals of the test circuit 3, and a contactor is installed in the control circuit 4. The contactor includes a main contact 413, which is located in the test circuit 3 to control the on / off state of the test circuit 3.

[0059] The testing device is equipped with a three-phase power supply to ensure power supply, and a main switch to control the on / off state of the entire testing circuit. A test circuit is set up to test the device under test, and a contactor is set up in the control circuit. By controlling the contactor, the on / off state of the test circuit can be controlled by adjusting the main contacts of the contactor. This allows the testing device to test the surge resistance of the device under test when the main contacts are open.

[0060] exist Figure 1 , 2 In this invention, considering the reasonable connection of the detection circuit 33 and ensuring its safety, in one embodiment of the present invention, the test circuit 3 includes three first fuses 37 and a main contact 413. One end of each of the three first fuses 37 is connected to the first end 31, the second end 32, and the third end 33 of the test circuit. The first end 3a, the third end 3c, and the fifth end 3e of the main contact are connected to the other end of each of the three first fuses 37. The second end 3b, the fourth end 3d, and the sixth end 3e of the main contact are connected to the fourth end 34, the fifth end 35, and the sixth end 36 of the test circuit. The first fuses 37 protect the entire detection circuit, and the main contact 413 can completely switch the device under test on and off.

[0061] exist Figure 1 , 2In order to detect the surge resistance capability of the device under test and ensure the proper connection of the detection circuit 3, in one embodiment of this utility model, the detection device can be any of those known in the art. The detection device can be an oscilloscope 38. The voltage probe 381 of the oscilloscope 38 is connected to the first end 3a of the main contact, and the current probe 382 of the oscilloscope 38 is connected to the second end 3b of the main contact. The voltage probe 381 is grounded, so that the pulse current and voltage of the device under test can be recorded at the moment when the main contact 413 is turned on and off.

[0062] exist Figure 1 , 2In order to realize the on / off control of the main contact 413 by the control circuit 4, and to realize the cyclic testing of the device under test and the recording of the number of cycles; in one embodiment of this utility model, the connection method of the control circuit is a connection method known to those skilled in the art. The control circuit 4 includes two second fuses 403, a switch 404, a selector switch 405, a normally closed relay (not shown in the figure), a first time delay relay (not shown in the figure), a second time delay relay (not shown in the figure), a meter 415, and a contactor (not shown in the figure). The normally closed relay includes a normally closed contact 406 and a normally closed coil 407. The first time delay relay includes a first coil 408 and a first normally open contact 409. The time relay includes a second coil 410 and a second normally open contact 411; the contactor includes a main contact 413, a normally open contact 414, and a contact coil 412; the meter 415 includes multiple contacts; one end of each of the two second fuses 403 is connected to the first terminal 401 and the second terminal 402 of the control circuit, respectively; one end of the switch 404 is connected to the other end of the second fuses 403 connected to the first terminal 401 of the control circuit; the first terminal 4051 and the third terminal 4053 of the selector switch are connected to the other end of the switch 404; one end of the normally closed contact 406 of the normally closed relay is connected to the second terminal 4052 of the selector switch; and the first coil 408 of the first time delay relay... One end of the first normally closed contact 406 of the first time delay relay is connected to the other end of the first coil 408 of the first time delay relay, and the other end of the second fuse 403 connected to the second terminal 402 of the control circuit is connected to the other end of the switch 404. One end of the first normally open contact 409 of the first time delay relay is connected to the other end of the switch 404. One end of the second coil 410 of the second time delay relay is connected to the other end of the first normally open contact 409 of the first time delay relay, and the other end of the second coil 410 of the second time delay relay is connected to the other end of the first coil 408 of the first time delay relay. One end of the second normally open contact 411 of the second time delay relay is connected to the other end of the switch 404. The other end of the closed contact 411 is connected to one end of the normally closed coil 407 of the normally closed relay. The first contact 5a and the second contact 5b of the meter are connected to the other ends of the two second fuses 403 respectively. One end of the contact coil 412 of the contactor is connected to one end of the second coil 410 of the second time delay relay. The other end of the contact coil 412 of the contactor is connected to the other end of the second coil 410 of the second time delay relay. The other end of the contact coil 412 of the contactor is connected to the other end of the normally closed coil 407 of the normally closed relay. One end of the normally open contact 414 of the contactor is connected to the third contact 5c of the meter. The other end of the normally open contact 414 of the contactor is connected to the fourth contact 5d of the meter.

[0063] When the control circuit 4 needs to cyclically switch the main contact 413 on and off to record the number of cycles and meet the surge resistance test requirements, when the selector switch 405 selects the switch position connected to the normally closed relay, the first terminal 4051 and the second terminal 4052 of the selector switch close, the normally closed contact 406 is closed, the first coil 408 is energized, and after a delay, the first normally open contact 409 closes. At this time, the second coil 410 and the contact coil 412 are energized, the main contact 413 and the normally open contact 414 close simultaneously, and the measuring instrument 415 is activated because of the normally open contact 414. The device is connected to the measuring instrument 415 to record the number of on / off cycles. When the main contact 413 is switched on or off, the detection device performs the detection. After a certain delay, the second normally open contact 411 of the second time delay relay closes. At this time, the normally closed coil 407 is turned on, the normally closed contact 406 is opened, the first coil 408 is turned off, the first normally open contact 409 is opened, the second coil 410 and the contact coil 412 are turned off, the main contact 413 and the normally open contact 414 are turned off, the second normally open contact 411 is turned off, and after the normally closed coil 407 is turned off, the normally closed contact 407 is closed, and the cycle is repeated to realize the cyclic on / off detection.

[0064] exist Figure 1 , 2 In this invention, considering the durability test of the device under test, its service life and power are tested. In one embodiment of this invention, the connection method of the control circuit is a connection method known in the art. The fifth contact 5e of the tester is connected to the fourth terminal 4054 of the selector switch, and the sixth contact 5f of the tester is connected to one end of the contact coil 412 of the contactor. At a preset time, when the selector switch 405 selects the switch position connected to the fifth contact 5e of the tester, the third terminal 4053 and the fourth terminal 4054 of the selector switch close. The fifth contact 5e and the sixth contact 5f of the tester are in a closed state, the tester outputs a timer, the second coil 410 and the contact coil 412 are connected, the main contact 413 and the normally open contact 414 are closed, the second time delay relay delays for a period of time, the second normally open contact 411 closes, the normally closed coil 407 is connected, and the normally closed contact 406 is opened. The rest of the circuit is not connected and will not affect the durability test. At this time, the device under test is in working state, and a power meter can be connected to the three-phase line to detect the power consumption of the device under test within the time set by the tester 415, detect its usage, and verify the durability time to be tested. When the preset time ends, the fifth contact and the sixth contact open, and the circuit is broken.

[0065] Through the above technical solution, the detection circuit and detection device are equipped with a three-phase power supply to ensure power supply, and a main switch is set to control the on / off state of the entire detection circuit. An oscilloscope is connected in the test circuit as a detection device to test the pulse current and voltage of the device under test at the moment the main contacts close. In the control circuit, a selector switch, normally closed relays, and time-delay relays are set. When the selector switch is selected to the switch position connected to the normally closed relay, the normally closed relay, the first time-delay relay, and the second time-delay relay control the contactor after closing in stages. The opening and closing of the main contacts and normally open contacts of the contactor control the on / off state of the test circuit and the counting of the tester, respectively. The normally closed contacts and coil of the normally closed relay, in cooperation with the first time-delay relay and the second time-delay relay, achieve cyclic on / off switching to perform surge resistance durability testing of the device under test and detect its service life. When the selector switch is selected to the switch position connected to the fifth and sixth contacts of the tester, the tester sets the durability time to be verified. During the set time, the main contacts of the contactor remain closed, so that the device under test is in working state, which facilitates the detection of the power consumption and durability of the device under test.

[0066] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention. It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe the various possible combinations.

[0067] Furthermore, various different embodiments of this utility model can be combined in any way, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.

Claims

1. A power on / off detection circuit for a low-voltage electrical component, characterized in that, The detection circuit includes: Three-phase circuit, connected to an external power source; The main switch, with its first, third, and fifth terminals connected to the L1, L2, and L3 lines of the three-phase circuit respectively; The test circuit has its first, second, and third ends connected to the second, fourth, and sixth ends of the main switch, respectively. The fourth, fifth, and sixth ends of the test circuit are connected to an external device under test (DUT). A detection device is installed in the test circuit to detect the DUT. A control circuit, wherein the first and second ends of the control circuit are connected to the first and second ends of the test circuit, and the control circuit is equipped with a contactor, wherein the main contacts of the contactor are located in the test circuit to complete the on / off control of the test circuit.

2. The detection circuit according to claim 1, characterized in that, The test circuit includes: Three first fuses, one end of each of the three first fuses being connected to the first, second and third ends of the test circuit respectively; The main contacts are connected to the other ends of the three first fuses at their first, third, and fifth ends respectively, and to the fourth, fifth, and sixth ends respectively of the test circuit at their second, fourth, and sixth ends respectively.

3. The detection circuit according to claim 2, characterized in that, The testing device is an oscilloscope. The voltage probe of the oscilloscope is connected to the first end of the main contact, the current probe of the oscilloscope is connected to the second end of the main contact, and the voltage probe is grounded.

4. The detection circuit according to claim 1, characterized in that, The control loop includes: Two second fuses, one end of each second fuse being connected to the first and second ends of the control circuit respectively; A switch, one end of which is connected to the other end of a second fuse that is connected to a first end of the control circuit; A selection switch, wherein the first and third ends of the selection switch are connected to the other end of the switch; A normally closed relay, wherein one end of the normally closed contact of the normally closed relay is connected to the second end of the selector switch; A first time-delay relay, one end of the first coil of the first time-delay relay is connected to the other end of the normally closed contact of the normally closed relay, the other end of the first coil of the first time-delay relay is connected to the other end of the second fuse connected to the second end of the control circuit, and one end of the first normally open contact of the first time-delay relay is connected to the other end of the switch; The second time-delay relay has one end of its second coil connected to the other end of the first normally open contact of the first time-delay relay, the other end of its second coil connected to the other end of the first coil of the first time-delay relay, one end of its second normally open contact connected to the other end of the switch, and the other end of its second normally open contact connected to one end of the normally closed coil of the normally closed relay. The measuring device, wherein the first contact and the second contact of the measuring device are respectively connected to the other ends of the two second fuses; The contactor has one end of its contact coil connected to one end of the second coil of the second time delay relay, the other end of its contact coil connected to the other end of the second coil of the second time delay relay, the other end of its contact coil connected to the other end of the normally closed coil of the normally closed relay, one end of its normally open contact connected to the third contact of the meter, and the other end of its normally open contact connected to the fourth contact of the meter.

5. The detection circuit according to claim 4, characterized in that, The fifth contact of the meter is connected to the fourth terminal of the selector switch, and the sixth contact of the meter is connected to one end of the contact coil of the contactor.

6. A power supply continuity testing device for low-voltage electrical components, characterized in that, The detection device includes: power supply; Three-phase circuit, connected to an external power source; The main switch, with its first, third, and fifth terminals connected to the L1, L2, and L3 lines of the three-phase circuit respectively; The test circuit has its first, second, and third ends connected to the second, fourth, and sixth ends of the main switch, respectively. The fourth, fifth, and sixth ends of the test circuit are connected to an external device under test (DUT). A detection device is installed in the test circuit to detect the DUT. A control circuit, wherein the first and second ends of the control circuit are connected to the first and second ends of the test circuit, and the control circuit is equipped with a contactor, wherein the main contacts of the contactor are located in the test circuit to complete the on / off control of the test circuit.

7. The detection device according to claim 6, characterized in that, The test circuit includes: Three first fuses, one end of each of the three first fuses being connected to the first, second and third ends of the test circuit respectively; The main contacts are connected to the other ends of the three first fuses at their first, third, and fifth ends respectively, and to the fourth, fifth, and sixth ends respectively of the test circuit at their second, fourth, and sixth ends respectively.

8. The detection device according to claim 7, characterized in that, The testing device is an oscilloscope. The voltage probe of the oscilloscope is connected to the first end of the main contact, the current probe of the oscilloscope is connected to the second end of the main contact, and the voltage probe is grounded.

9. The detection device according to claim 6, characterized in that, The control loop includes: Two second fuses, one end of each second fuse being connected to the first and second ends of the control circuit respectively; A switch, one end of which is connected to the other end of a second fuse that is connected to a first end of the control circuit; A selection switch, wherein the first and third ends of the selection switch are connected to the other end of the switch; A normally closed relay, wherein one end of the normally closed contact of the normally closed relay is connected to the second end of the selector switch; A first time-delay relay, one end of the first coil of the first time-delay relay is connected to the other end of the normally closed contact of the normally closed relay, the other end of the first coil of the first time-delay relay is connected to the other end of the second fuse connected to the second end of the control circuit, and one end of the first normally open contact of the first time-delay relay is connected to the other end of the switch; The second time-delay relay has one end of its second coil connected to the other end of the first normally open contact of the first time-delay relay, the other end of its second coil connected to the other end of the first coil of the first time-delay relay, one end of its second normally open contact connected to the other end of the switch, and the other end of its second normally open contact connected to one end of the normally closed coil of the normally closed relay. The measuring device, wherein the first contact and the second contact of the measuring device are respectively connected to the other ends of the two second fuses; The contactor has one end of its contact coil connected to one end of the second coil of the second time delay relay, the other end of its contact coil connected to the other end of the second coil of the second time delay relay, the other end of its contact coil connected to the other end of the normally closed coil of the normally closed relay, one end of its normally open contact connected to the third contact of the meter, and the other end of its normally open contact connected to the fourth contact of the meter.

10. The detection device according to claim 9, characterized in that, The fifth contact of the meter is connected to the fourth terminal of the selector switch, and the sixth contact of the meter is connected to one end of the contact coil of the contactor.

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