Method for calculating relay contact rebound

Abstract

The invention provides a method for calculating the rebounding of a relay contact, and the method is used for calculating the rebounding of the relay contact in a one-time action process, and the one-time action process of the contact is a process that a relay coil completes one-time excitation, the contact is turned from a normally-closed contact to a normally-open contact to be closed, and the normally-open contact is closed stably; the method comprises the following steps of: extracting rebound data of a contact in real time from the beginning of one-time action of the contact, judging whether the rebound data is generated by attraction rebound of the contact or not, if the rebound data is generated by attraction rebound of the contact, recording the starting time and the ending time of a pulse width in the rebound data, calculating the size of the pulse width and storing until the one-time action of the contact is finished, and if the rebound data is generated by attraction rebound of the contact, recording the starting time and the ending time of the pulse width in the rebound data. Forming a pulse width data set; when the contact rebound data extracted in real time meets the condition that the pulse width amplitude is larger than or equal to 90% of the open-circuit voltage, it is judged that contact pull-in rebound is generated, and the open-circuit voltage is the open-circuit voltage of the relay. According to the calculation method, each piece of independent rebound data is calculated, and the result is more accurate.

Description

Technical Field

[0001] The invention belongs to the field of electric contact, and in particular relates to a method for calculating the bounce of relay contacts, which is used for analyzing bounce data generated during the action and release process of electromagnetic relay contacts. Background Art

[0002] In the relay industry, product bounce is a key factor affecting product life indicators. Therefore, how to control bounce is a key research topic in the industry. In the relay manufacturing industry, when the relay operates once and the contact closes, one or more bounces will occur. For example, Figure 1 As shown, each dark portion represents a contact bounce.

[0003] At present, the relay industry uses a comprehensive parameter tester to test bounce parameters. This device is defined according to the current product specifications. During one action of the test product, the device starts counting when the contacts are just in contact. It determines whether the contact voltage is equal to or greater than 90% of the open circuit voltage and whether the pulse width is equal to or greater than 10uS. When both conditions are not met or one of them cannot meet the conditions, the timing is stopped. The obtained time is the contact bounce time. Figure 1 as shown in .

[0004] This bounce test method can meet the product life index requirements, but as military aviation and aerospace users have higher and higher requirements on the quality and reliability of relays, the product life index requirements are improved, and new surge resistance index requirements are proposed. The existing bounce test method cannot meet the purpose of accurate testing. Summary of the invention

[0005] The purpose of the present invention is to provide a method for calculating the bounce of relay contacts, which method can accurately obtain the relay bounce data to meet the purpose of accurate testing.

[0006] The present calculation method calculates the contact bounce during a relay contact action. The contact action process is the process when the relay coil completes one excitation, the contact switches from a normally closed contact to a normally open contact, and the normally open contact closes and stabilizes. The method extracts the contact bounce data in real time from the beginning of the contact action, and determines whether the bounce data is generated by contact pull-in bounce. If it is generated by contact pull-in bounce, the start time and end time of the pulse width in the bounce data are recorded, and the size of the pulse width is calculated and stored until the contact action ends, forming a pulse width data group.

[0007] When the contact bounce data extracted in real time meets the pulse width amplitude ≥ 90% of the open circuit voltage, it is judged that the contact pull-in bounce occurs, and the open circuit voltage is the open circuit voltage of the relay.

[0008] In some embodiments, when the bounce data is generated by contact closure bounce, the method selects the point where the rising edge meets the voltage of 90% of the open circuit voltage as the bounce starting point, and selects the point where the falling edge meets the voltage of 90% of the open circuit voltage as the bounce end point.

[0009] The beneficial effects of the present invention are as follows: the calculation method identifies all bounce data under one action of the relay contact respectively, and stores the start and end time and pulse width of the bounce data generated by the pull-in bounce to form a pulse width data group; compared with the traditional method that can only measure the length of the waveform from the moment the contact just touches to the last waveform that satisfies the bounce voltage greater than 90% of the open circuit voltage and the bounce pulse width greater than 10us, which is the sum of multiple bounce pulse width times and the non-bounce pulse width time between the moment the contact just touches to the last bounce that meets the judgment conditions, the calculation method calculates each individual bounce data, and the result is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The drawings herein are incorporated into and constitute a part of the specification, showing embodiments consistent with the invention, and together with the specification, are used to explain the principles of the invention. Obviously, the drawings described below are only some embodiments of the 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:

[0011] Figure 1 The contact bounce waveform diagram described in the background technology of the present invention;

[0012] Figure 2 A bounce flow chart of the method for calculating the bounce of relay contacts provided by the present invention;

[0013] Figure 3 A schematic diagram of data derived from an oscilloscope test of the electromagnetic relay provided by the present invention;

[0014] Figure 4 This is the electromagnetic relay contact bounce waveform captured by the oscilloscope;

[0015] Figure 5 A diagram showing a portion of a MATLAB program for calculating the bounce pulse width provided by the present invention;

[0016] Figure 6 Part 2 of the Matlab program for calculating the bounce pulse width provided by the present invention;

[0017] Figure 7 This is a schematic diagram of the output of calculating the bounce pulse width according to the present invention. DETAILED DESCRIPTION

[0018] 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 invention will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0019] In addition, the described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the invention. However, those skilled in the art will appreciate that the technical solutions of the invention may be practiced without one or more of the specific details, or other methods may be used. In other cases, known methods, implementations or operations are not shown or described in detail to avoid blurring the various aspects of the invention.

[0020] The flowchart of the method for calculating the relay contact bounce provided by the present invention is as follows: Figure 2 As shown, first use an oscilloscope to test the relay bounce to generate bounce data. The bounce waveform collected by the oscilloscope is as follows Figure 4 As shown, the horizontal axis is the sampling time, and the vertical axis is the signal voltage amplitude. When the contacts just touch, that is, when the signal changes from high level to low level for the first time, the time starts from 0. After the measurement, export the data into the computer and save it in a separate folder. Figure 3 As shown, the data is a csv file with consecutive numbers, and each file represents the bounce data of a group of contacts of the test relay acting once.

[0021] The contact action process is the process of the relay coil completing one excitation, the contact changing from normally closed contact opening to normally open contact closing, and the normally open contact closing being stable.

[0022] Read a csv file, extract the bounce data of each contact, and determine whether the bounce data is caused by the contact closing bounce. If it is caused by the contact closing bounce, record the start time and end time of the pulse width in the bounce data, and calculate the size of the pulse width for storage until the contact action is completed, forming a pulse width data group.

[0023] When the contact begins to close, the voltage signal at both ends changes from high level to low level, and then rebound occurs. When the rebound begins, the voltage signal changes from low level to high level. At this time, the signal is judged to be a rising edge, and the point where the rising edge meets the voltage of 90% of the open circuit voltage is selected as the rebound starting point. From the starting point, when the voltage changes from high level to low level, the signal is judged to be a falling edge, and the point where the falling edge meets the voltage of 90% of the open circuit voltage is selected as the rebound end point. Based on this, when the extracted rebound data meets the pulse width amplitude ≥ 90% of the open circuit voltage, it is judged that the contact is attracted and rebounded, the open circuit voltage is the open circuit voltage of the relay, and the point where the rising edge meets the voltage of 90% of the open circuit voltage is selected as the rebound starting point, and the point where the falling edge meets the voltage of 90% of the open circuit voltage is selected as the rebound end point.

[0024] The formed pulse width data group includes the pulse width size of each bounce data, the starting point and end point of the pulse width, and the pulse width start time and end time.

[0025] This calculation method can be built by any third-party system with programming function, such as using MATLAB, and putting the MATLAB test jump program and test data into the same folder, such as Figure 3 The last file shown is a matlab program. Double-click the program and click Run. After the run is completed, the calculation results are output. The output calculation results are pulse width data groups.

[0026] Combination Figure 5 , 6 As shown, the program code of this calculation method is described as follows.

[0027] Some lines are too long to be represented in one line, so a serial number is added before the program code to indicate the line number of the code. There are 54 lines in total. The following is a description of each line:

[0028] The first line indicates the program name;

[0029] Line 2 indicates setting a local variable;

[0030] Lines 3 to 8 define the headers of the first row, first column to the 17th column of the final output table;

[0031] Line 9 sets up a for loop, that is, when the calculation jumps back, Figure 3 Start counting from the first file in the table and continue until the last file;

[0032] Lines 10-14 define local variables to enable Matlab to read the attached Figure 3 The starting position of the data in a, where changing the value of 0 in a=0 can set the numbering position where the data starts to be read;

[0033] Line 15 converts the value of a into a string, that is, converts 1 into 00001, and 11 into 00011. Figure 3 The number after the saved data name should be kept consistent so that it can be identified when the program calls the file data later;

[0034] The 16th row indicates that the table numbers are stored in the final output table in order, fixed in the first column, and stored starting from the second row;

[0035] Line 17 indicates reading the attached Figure 3 where ['C1Trace', t, '.csv'] represents the file name and t is the number in the file name, i.e. the number converted in row 15.

[0036] Line 18 means reading the data in line 17, that is, reading Figure 4 The rebound abscissa shown in ;

[0037] Line 19 reads the data in line 17 of the file, that is, reads Figure 4 The rebound amplitude shown in ;

[0038] Line 20 sets a variable to indicate the starting and ending points of each bounce pulse width.

[0039] Line 21 indicates that the file number currently being calculated is displayed in the program, which is optional;

[0040] Line 22 indicates setting a variable for the location selection when storing the jump pulse width data later;

[0041] Line 23 sets up a loop to calculate the attached Figure 4 The range of the rebound is shown.

[0042] Lines 24 to 27 indicate the starting position of the back jump calculation;

[0043] Line 28 indicates that the jump start position calculated in lines 24 to 27 is displayed in the program, which is optional.

[0044] Line 29 indicates that the jump start position calculated in lines 24 to 27 is stored in the corresponding table output at the end;

[0045] Line 30 indicates that after a data is stored in line 29, the storage location is automatically incremented by 1, so that the next data is stored in the next location;

[0046] Lines 31 to 34 indicate the end point of the jump back calculated in lines 24 to 27;

[0047] Line 35 indicates that the jump start position calculated in lines 31 to 34 is displayed in the program, which is optional.

[0048] Line 36 indicates that the jump start position calculated in lines 31 to 34 is stored in the corresponding table output at the end;

[0049] Line 37 indicates that after a data is stored in line 36, the storage location is automatically incremented by 1 so that the next data is stored in the next location;

[0050] Lines 38 to 40 indicate that the jump end point stored in line 36 is subtracted from the jump start point stored in line 29 to obtain the jump pulse width, which is then stored in the final output table.

[0051] Line 41 indicates that after a data is stored in line 40, the storage location is automatically incremented by 1 so that the next data is stored in the next location;

[0052] Line 42 means ending the if statement in line 24 and entering the next loop in line 23;

[0053] Line 43 means ending the for loop statement in line 23 and entering the next loop in line 9;

[0054] Line 44 indicates that an initial value of 0 is assigned to the second column of the final output table of the current loop;

[0055] Lines 45 to 52 represent a loop for line 9, i.e. Figure 3 Compare all the bounce pulse widths obtained in a file shown in the figure to obtain the maximum bounce pulse width, and store the pulse width value in the second column of the final output table;

[0056] Line 53 indicates the end of the for loop in line 9;

[0057] Line 54 indicates that Figure 3 All calculation results are output as Excel tables. The output results are as shown in the attached Figure 7 shown.

[0058] Attached Figure 7 The final output result of the calculation of the bounce is shown in the first column, the second column is the maximum bounce pulse width, and the third column is the starting point, end point and pulse width of each bounce. Some numbers have more than 5 bounce pulse widths, but the attached Figure 5 In the 3rd to 8th lines, only 5 jump pulse widths are defined, and there is no subsequent pulse width. You can define it yourself after output.

[0059] The output result of this calculation method can be based on the index requirements of a specific load. The pulse width value needs to be specified for a specific load, such as outputting the maximum pulse width according to the needs of a specific load (surge load, peak current ≤15A, surge pulse width ≤100μs). This calculation method can set the time length for calculating rebound according to actual needs, such as the rebound generated by the contact when the normally open contact is closed after the product is excited. During one action, after the product is excited, an armature rebound will also be generated when the action reaches the end. Contact rebound usually occurs within 100μs after the contact is connected, and armature rebound usually occurs after 100μs after the contact is connected. When considering the impact of armature rebound on the relay, a method can be used to collect armature rebound data.

[0060] The present invention discloses a method for calculating the bounce of relay contacts. The method first uses an oscilloscope to test the bounce of the relay, stores the test data and imports it into a computer, calculates the bounce program, and finally outputs the bounce data of a single action of the relay, including the maximum bounce pulse width, each bounce pulse width and the starting position of each bounce. Compared with the method of using a comprehensive parameter instrument to test the bounce in the relay industry, the method for calculating the bounce of the relay of the present invention can accurately obtain the specific data of the bounce of the relay, which is of great significance for studying the life of the relay.

[0061] 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. A method for calculating relay contact bounce, characterized in that: This method calculates the contact bounce during one action of the relay contact. One action of the contact is the process when the relay coil completes one excitation, the contact changes from the normally closed contact to the normally open contact, and the normally open contact is closed and stable. The method extracts the bounce data of each contact in real time from the beginning of one contact action, and determines whether the bounce data is caused by contact closure bounce. If it is caused by contact closure bounce, the start time and end time of the pulse width in the bounce data are recorded, and the size of the pulse width is calculated and stored until the contact action ends, forming a pulse width data group; when the contact bounce data extracted in real time meets the pulse width amplitude ≥ 90% of the open circuit voltage, it is determined to be caused by contact closure bounce, and the open circuit voltage is the open circuit voltage of the relay.

2. The method for calculating relay contact bounce according to claim 1, characterized in that: When the bounce data is generated by contact closure bounce, the point where the rising edge meets the voltage of 90% of the open circuit voltage is selected as the bounce starting point, and the point where the falling edge meets the voltage of 90% of the open circuit voltage is selected as the bounce end point.

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