A voltage drop test device for AC contactor

Abstract

The present invention discloses an AC contactor voltage drop test device, which includes a data acquisition module for collecting voltage values ​​at both ends of the contacts after the contacts of the AC contactor to be tested are closed; and a data processing module for analyzing and processing the voltage values ​​collected by the data acquisition module to obtain the voltage drop values ​​at both ends of the contacts of the AC contactor to be tested, and converting them into digital and displaying them. The voltage drop test device provided by the present invention collects the voltage values ​​at both ends of the contacts through the data acquisition module, processes and displays them through the data processing module, and the resistance of the contacts of the AC contactor to be tested can be obtained according to the displayed voltage drop data. The device realizes the effective collection, processing and display of the voltage at both ends of the contacts of the AC contactor, greatly reducing the probability of safety accidents occurring in the AC contactor during the contact voltage drop collection process.

Description

Technical Field

[0001] The invention belongs to the field of electronic appliances, and in particular relates to an AC contactor voltage drop testing device. Background Art

[0002] During the manufacturing, screening and testing of contactors, the contact resistance assessment method is directly used to characterize the resistance capacity of the contacts. This method cannot effectively reflect the actual situation of the contact resistance. Therefore, it is necessary to test the contact voltage drop at both ends of the contacts under rated current and rated voltage conditions to better characterize the resistance of the contacts. However, there is currently no test device that can directly test both ends of the contacts. The test data is tested by using a multimeter to test the voltage drop at both ends of the contacts (the collection points are inconsistent each time, and the consistency of the collected data is poor). However, the current AC contactor voltage is basically 115V and 380V, and the distance between groups of products with multiple groups of contacts is small, which makes it easy for safety incidents to occur during the test. Based on the above factors, a device that can directly test the contact voltage drop is needed. Summary of the invention

[0003] The purpose of the present invention is to provide an AC contactor voltage drop testing device which can effectively collect, process and display the voltage drop data at both ends of the AC contactor contacts, thereby greatly reducing the probability of safety accidents occurring during the contact voltage drop collection process of the AC contactor.

[0004] To achieve the purpose of the present invention, the AC contactor voltage drop test device provided herein includes a data acquisition module, which is used to collect the voltage value across the contacts of the AC contactor to be tested after the contacts are closed; and a data processing module, which is used to analyze and process the voltage value collected by the data acquisition module to obtain the voltage drop value across the contacts of the AC contactor to be tested, and convert it into a digital value and display it.

[0005] Furthermore, the voltage drop testing device provided by the present invention also includes an overvoltage protection module. After the contacts of the AC contactor to be tested are closed, the data acquisition module collects the voltage value at both ends of the contacts and inputs it into the overvoltage protection module. When the voltage value at both ends of the contacts of the AC contactor to be tested is greater than a threshold value, the overvoltage protection module cuts off the path between the data acquisition module and the data processing module.

[0006] During the test, the contacts may not close normally. At this time, the actual voltage across the contacts is as high as 115V. If the data acquisition module works directly at this time, the voltage will directly burn the data acquisition module. Therefore, the present invention uses an overvoltage protection module to disconnect the acquisition circuit of the data acquisition module when the voltage across the contacts of the AC contactor to be tested is higher than a set value, thereby protecting the data acquisition module from being burned.

[0007] Furthermore, the voltage drop test device provided by the present invention also includes a start module, the start module includes a first switch S1 and a second relay, the other input terminal of the overvoltage protection chip U1 for inputting the voltage value is connected to the normally open contact of the second relay, the normally closed contact of the second relay is connected to the normally closed contact of the first relay, and the normally closed contact of the second relay is connected to the data processing module; the excitation is loaded on the coil of the second relay through the first switch S1. The start-stop module realizes the one-key acquisition of the voltage at both ends of the contacts of the AC contactor to be tested, and the operation is simple.

[0008] Furthermore, the voltage drop test device provided by the present invention also includes an adjustable voltage conversion module for providing different operating voltages for different AC contactor coils to be tested.

[0009] During the voltage drop test of the AC contactor contacts, the contactor coil needs to be controlled to realize the opening and closing function of the contactor contacts. For contactors of different specifications, the coil voltages are different. The present invention provides different working voltages through an adjustable voltage conversion module to meet the voltage drop test of contactors of different specifications, thereby expanding the applicability of the voltage drop test device provided by the present invention.

[0010] Furthermore, the voltage drop test device provided by the present invention also includes a data holding module, which is used to hold and display the voltage drop value processed by the data processing module. The data holding module can freeze the data on the display screen, thereby reducing data loss during the acquisition process.

[0011] Furthermore, the voltage drop testing device provided by the present invention also includes a power supply module, and the power supply module includes a voltage conversion circuit and / or a voltage reduction circuit for converting 220V AC power into DC power.

[0012] Furthermore, the power supply module also includes an AC input control circuit for power supply control, which disconnects the live wire of the AC input when a short circuit occurs. The short circuit protection of the device is achieved through the AC input control circuit.

[0013] The beneficial effects of the present invention are as follows: the voltage drop test device provided by the present invention collects the voltage value at both ends of the contact through the data acquisition module, processes and displays it through the data processing module, and obtains the resistance of the contact of the AC contactor to be tested according to the displayed voltage drop data. The device realizes the effective collection, processing and display of the voltage at both ends of the contact of the AC contactor, greatly reducing the probability of safety accidents occurring in the process of collecting the contact voltage drop of the AC contactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings herein are incorporated into and constitute a part of the specification, showing embodiments consistent with the present invention, and together with the specification, are used to explain the principles of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0015] Figure 1 This is one of the partial circuit diagrams of the AC contactor voltage drop test device provided in this article;

[0016] Figure 2 This is the second partial circuit diagram of the AC contactor voltage drop test device provided in this article;

[0017] Figure 3 This is the circuit schematic diagram of the overvoltage protection module provided in this article;

[0018] Figure 4 This is the circuit schematic diagram of the start-stop module provided in this article;

[0019] Figure 5 This is the circuit connection diagram of the overvoltage protection module and start-stop module provided in this article;

[0020] Figure 6 The circuit connection diagram of the data processing module and data holding module provided in this article;

[0021] Figure 7 This is the second circuit schematic diagram of the AC input control circuit provided in this article;

[0022] In the accompanying drawings: J3, J4 and J5 are represented as the first relay, J6, J7 and J8 are the second relay, and J1 and J2 are the third relay. DETAILED DESCRIPTION

[0023] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present invention will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0024] Reference Figure 1-Figure 6 As shown in the figure, the AC contactor voltage drop test device provided in this article includes the following functional modules:

[0025] A power supply module is used to convert AC power into DC power, including an AC input control circuit, a voltage conversion circuit and / or a step-down circuit; Figure 1As shown, the AC input control circuit includes a fuse F1, a resistor R35 and an indicator LED1. The fuse F1 is connected in series to the live wire end of the AC power to achieve short-circuit protection for the device. The resistor R35 and the indicator LED1 are connected in series between the live wire end and the neutral wire end of the AC power. The indicator LED1 realizes the indication function. When the AC 220V is loaded, the indicator LED1 is in working state to indicate the power supply. Figure 1 As shown, the voltage conversion circuit is a DC switching power supply, whose input end is connected to the output end of the AC input control circuit. After rectifying and filtering the 220V AC power, the module can directly convert the 220V AC power into DC power to provide the corresponding working voltage for the internal devices; the DC switching power supply can use any switching power supply with a current not exceeding 12A, such as the SE-600-48 switching power supply, which outputs 48V DC power. The step-down circuit here uses a high-power step-down circuit, including a high-power DC-DC step-down chip and a resistor R36. The DC power output by the voltage conversion circuit is stepped down by the high-power DC-DC step-down chip to provide the working voltage of the relevant functional modules; the voltage after the step-down circuit can be set according to the functional module, such as 12V DC voltage.

[0026] The adjustable DC voltage conversion module is used to provide different working voltages for different AC contactor J9 coils to be tested. Figure 1 As shown, the adjustable DC voltage conversion module includes a digital encoder, a potentiometer connected to the digital encoder through a switch S4, and a liquid crystal display connected to the digital encoder for communication; the input voltage of the digital encoder is provided by a voltage conversion circuit, and the output end of the digital encoder is used to receive the coil of the test AC contactor J9, and output different voltages according to the different specifications of the AC contactor J9 to be tested.

[0027] By controlling the on and off of switch S4, the on and off times of the contactor can be manually controlled. The potentiometer can be adjusted to change the signal of the input digital encoder to achieve the purpose of outputting different voltages. The LCD screen is used to display the output voltage of the digital encoder, so that the output voltage of the digital encoder can be intuitively known. An internal program that can be run after power-on is stored in this digital encoder. After power-on, the program runs to control the on and off times according to the on and off of switch S5, and adjusts the potentiometer to make the digital encoder output different voltage values. Here, the digital encoder, LCD screen, potentiometer and switch S5 are combined into a DPX6012 module.

[0028] The data acquisition module is used to collect the voltage value at both ends of the contact after the contact of the AC contactor J9 to be tested is closed. Figure 1As shown, the data acquisition module used in this article is the contactor acquisition terminal J1. One end of the contactor acquisition terminal J1 is used to connect to the two ends of the contacts of the AC contactor J9 to be tested, and the other end is used to connect to the data processing module; the line between the contactor acquisition terminal J1 and the data processor is the acquisition line. The number of terminals of the contactor acquisition terminal J1 can be determined according to the number of contacts of the AC contactor J9 to be tested, such as Figure 1 As shown, the AC contactor J9 to be tested includes three groups of contacts, and the number of the contactor collection terminal J1 is 6, two by two form a group, and are used to connect to the two ends of a contact of the AC contactor J9 to be tested.

[0029] The start-stop module is used to start and stop the voltage drop test device provided in this article.

[0030] Overvoltage protection module: After the contact of the AC contactor J9 to be tested is closed, the data acquisition module collects the voltage value at both ends of the contact and inputs it into the overvoltage protection module. When the voltage value at both ends of the contact of the AC contactor J9 to be tested is greater than the threshold value, the overvoltage protection module cuts off the path between the data acquisition module and the data processing module.

[0031] The data processing module is used to analyze and process the contact voltage collected by the data acquisition module, convert it into digital and display it. The data processing module in this article uses a liquid crystal display DM4A-V2-R3, which is used to analyze and process the data collected by the data acquisition module, convert it into specific numerical values ​​for display. When the test range is exceeded, the letters AHT will be displayed on the display screen. The number of data processing modules is determined according to the number of contacts of the AC contactor J9 to be tested, combined with Figure 2 and Figure 6 As shown, the AC contactor J9 to be tested includes three groups of contacts, and the data processing module matches the number of contact groups to achieve the purpose of one-to-one testing; of course, only one data processing module can be used to realize multiple groups of data processing and display.

[0032] The data holding module is used to keep the data displayed by the data processing module unchanged.

[0033] like Figure 2 , Figure 3 , Figure 5 As shown, the overvoltage protection module in this article includes an overvoltage protection chip U1 and a first relay. The voltage values ​​collected by the data acquisition module are respectively input into the voltage protection chip U1; an input terminal of the overvoltage protection chip U1 for inputting the voltage value is connected to the normally closed contact of the first relay, and the normally closed contact of the first relay is connected to the data processing module; when the voltage value at both ends of the contact of the AC contactor J9 to be tested is greater than the threshold value, the overvoltage protection chip U1 outputs a control excitation to be loaded on the coil of the first relay.

[0034] like Figure 2 , Figure 4 , Figure 5 As shown, the start-stop module in this article includes a first switch S1 and a second relay, the other input terminal of the overvoltage protection chip U1 for inputting a voltage value is connected to the normally open contact of the second relay, the normally closed contact of the second relay is connected to the normally closed contact of the first relay, and the normally closed contact of the second relay is connected to the data processing module; the excitation is loaded on the coil of the second relay through the first switch S1.

[0035] like Figure 2 , Figure 6 As shown, the data retention module in this article includes a second switch S2 and a third relay, and the normally closed contact and the normally open contact of the third relay are respectively connected to the data processing module. When the second switch S2 is pressed, the third relay starts to work, the normally open contact is closed, and the data retention judgment end of the data processing module is closed, so that the data displayed by the data processing module remains unchanged.

[0036] This article takes the AC contactor J9 to be tested including three groups of contacts as an example to further illustrate the circuit principle of the voltage drop test device provided in this article.

[0037] The contactor acquisition terminal J1 matching the number of contacts of the AC contactor J9 to be tested includes six connection terminals, namely, acquisition point 1 to acquisition point 6, where acquisition point 1 and acquisition point 2 form a group, acquisition point 3 and acquisition point 4 form a group, and acquisition point 5 and acquisition point 6 form a group; the number of groups of overvoltage protection module, data processing module, start-stop module and data holding module is the same as the number of contacts of the AC contactor J9 to be tested; the circuit connection relationship is combined Figure 1-Figure 6 shown.

[0038] The test process is as follows: load AC 22V, output +12V DC after AC input control circuit, voltage conversion circuit and step-down circuit; the output of the voltage conversion circuit is connected to the adjustable voltage conversion module, and the adjustable voltage conversion module is used to load excitation for the AC contactor J9 coil to be tested, so that its contact A, contact B and contact C are closed. At this time, press the first switch S1 to energize the first relay coil, and the voltage of the contactor acquisition terminal J1 acquisition point 1-acquisition point 6 is input to the data processing module. The data processing module analyzes and processes the input voltage signal to obtain the voltage drop value at both ends of the contact of the AC contactor J9 to be tested, and converts it into digital and displays it.

[0039] During the test, if the contacts of the AC contactor J9 to be tested fail to close normally, causing the voltage across the contacts of the AC contactor J9 to be tested to be higher than the set value, the overvoltage protection chip U1 outputs a signal to control the third relay to work, the normally closed contact is disconnected, the acquisition line is disconnected, and the data acquisition module is protected; when the voltage across the closed contacts of the AC contactor J9 to be tested is lower than the set value, the third relay is reset, the normally closed contact is closed, the acquisition line is connected, and the data acquisition module works normally.

[0040] During the test, the third relay coil can be energized by pressing the second switch S2, so that the third relay is activated to input a freeze data signal to the data processing module to freeze the data displayed by the data processing module.

[0041] When the test is completed, the test can be stopped through the first switch S1, or if the test needs to be stopped during the test, it can also be controlled by the first switch S1.

[0042] In order to realize the control of AC 220V input, a third switch S3 is added to the AC input control circuit. The third switch S3 and the F1 fuse are connected in series at the live wire end to realize the total power control of the device. Figure 7 shown.

[0043] The voltage drop test device provided in this article realizes the acquisition, processing and maintenance of the AC voltage at both ends of the AC contactor contacts through the mutual cooperation between the above modules, thereby achieving the purpose of voltage drop testing.

[0044] The present disclosure has been described by the above-mentioned relevant embodiments, but the above-mentioned embodiments are only examples for implementing the present disclosure. It must be pointed out that the disclosed embodiments do not limit the scope of the present disclosure. On the contrary, changes and modifications made without departing from the spirit and scope of the present disclosure are all within the scope of patent protection of the present disclosure.

Claims

1. An AC contactor voltage drop test device, characterized in that: The device includes a data acquisition module for acquiring voltage values ​​at both ends of the contacts of the AC contactor to be tested after the contacts are closed; and a data processing module, which is used to analyze and process the voltage value collected by the data collection module to obtain the voltage drop value at both ends of the contacts of the AC contactor to be tested, and convert it into digital and display it; It also includes a data holding module, which is used to hold and display the voltage drop value processed by the data processing module, and the data holding module includes a second switch S2 and a third relay, and the normally closed contact and the normally open contact of the third relay are respectively connected to the data processing module; It also includes an overvoltage protection module, which includes an overvoltage protection chip U1 and a first relay. After the contacts of the AC contactor to be tested are closed, the data acquisition module collects the voltage values ​​at both ends of the contacts and inputs them into the voltage protection chip U1 respectively. An input terminal of the overvoltage protection chip U1 for inputting the voltage value is connected to the normally closed contact of the first relay, and the normally closed contact of the first relay is connected to the data processing module. When the voltage value at both ends of the contacts of the AC contactor to be tested is greater than a threshold value, the overvoltage protection chip U1 outputs a control excitation to load the coil of the first relay to cut off the path between the data acquisition module and the data processing module. The start-stop module also includes a first switch S1 and a second relay. Another input terminal of the overvoltage protection chip U1 for inputting the voltage value is connected to the normally open contact of the second relay, and the normally closed contact of the second relay is connected to the first The normally closed contact of the relay, the normally closed contact of the second relay is connected to the data processing module; the excitation is loaded on the coil of the second relay through the first switch S1.

2. The AC contactor voltage drop test device according to claim 1, characterized in that: The device also includes a start-stop module, and the voltage value collected by the data collection module is input into the data processing module when the start-stop module is in a working state.

3. The AC contactor voltage drop test device according to claim 1, characterized in that: The device also includes an adjustable voltage conversion module, which is used to provide different working voltages for different AC contactor coils to be tested.

4. The AC contactor voltage drop test device according to any one of claims 1 to 3, characterized in that: The device also includes a power supply module, which includes a voltage conversion circuit and / or a voltage reduction circuit for converting 220V AC power into DC power.

5. The AC contactor voltage drop test device according to claim 4, characterized in that: The power supply module also includes an AC input control circuit for power supply control, which disconnects the live wire end of the AC input when a short circuit occurs.

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