SU1690019A1 - Method of forecasting tests and electromagnetic relay quality check - Google Patents

Abstract

The invention relates to the field of measurement of permissible control, diagnostics of parameters, prediction of reliability and statistical tests of mainly low-current, compact electromagnetic relays. The purpose of the invention is to reduce the labor intensity and increase the reliability of the control. The method is as follows. A sequence of pulses is applied to the relay coil, the duty cycle of which is two, and the frequency is close to the maximum switching frequency for this type of relay (to reduce the total monitoring time). During the duration of each pulse, information about the state of the contacts is read with a sampling interval G0, which is significantly less than the jitter of contacts in the time interval from l to l, where l and T2 are statistically determined for each type of relay, respectively, the minimum and maximum response times. for each relay, the response time and bounce time are determined, and after the end of the pulse sequence, for each relay, the response time, bounce time, difference and between the first and average response times, the standard deviations of the response times and the bounce time, which are then compared with the established norms for these values, and, based on the comparison results, they decide on the quality of the relay.3 Il. SO s o y o o h

Description

The invention relates to the field of measurement, tolerance control, diagnostics of parameters, reliability prediction and statistical tests, mainly low-current, compact electromagnetic relays.

The purpose of the invention is to reduce the labor intensity and increase the reliability of the control.

Figure 1 shows a diagram of the device that implements the proposed method; 2 shows timing diagrams explaining the operation of the device, where A is the sequence of a series of control pulses triggered on the relay coil with a switching frequency fk fkM3Kc, B is the voltage at the closing contact, C is the polling pulses of the relay contact closing states, G - recording pulses of the relay contact closure states array; FIG. 3 is a histogram of the distribution of the difference between the first and the average response time of the RES49 relay.

A device that implements the method, contains a computer I with a block 2 input programs, video terminal 3 and block 4 output information to print, drivers 5 and 6, respectively, signals affecting

relay coils and signals for reading information about the state of contacts, controllable power supply unit 7, contact node 8, monitored relays 9 and their contacts 10.

The device works as follows.

Through block 2, the input of programs in the memory of computer I brings the control program. The monitored relays 9 are installed in the contact node 8. From the keyboard of the video terminal 3, information about the relay is entered into the computer I: type of relay, validity criterion value. Upon completion of the input of information, the computer I, in accordance with the type of the specified relay, is influenced by the input of the controlled power supply unit 7, the output of which is set to the specified power supply voltage of the relay coils 9. Thereafter, through the imaging unit 5, the computer I sets a series of control pulses (Fig. 2, diagram A) on the winding of the relay 9 with the switching frequency tk .. For the duration of each control pulse of the series from the output of the imaging unit 6, the computer reads information about the state of the contacts 10 with the sampling interval r0 (figure 2, diagram B), much smaller contact bounce period, in the time interval from n to T2 (Fig.2, Chart D), where ri and yy are statistically determined for each type of relay, respectively, the minimum and maximum response times, in the memory creates an array of contact states in real time. From the time T2 until the beginning of the next control pulse, the computer I determines and remembers the response time and the bounce time of each relay (Fig. 2, diagram B) and repeats the measurement cycle in the series.

At the end of a series of control pulses, the computer processes the results obtained for each relay separately and compare the maximum permissible norms of the response time and chatter, the difference between the first and the average for the series of operation time, the standard deviation of the response time and chatter. The result of processing the measurement results of the computer I and displays the video terminal 3 or for printing for each relay: its virtual number, the difference between the first and average response times, the standard deviations of the response times and bounce, as well as the relay reliability message.

To confirm the positive effect, tests of the REO490S type were carried out, which included measuring the difference between the first and average response times by the method described and testing the wear resistance of the relay contacts in the self-oscillation mode. According to the measurement results, a histogram of the distribution of the difference between the first and the average response time for 348 pcs was constructed. relay type RES-49, shown in Fig.Z. Based on the distribution histogram, two groups of relays were selected: the first consists of relays having difference values whose relative frequency of occurrence is less than or equal to 0.005; the second group consists of relays having difference values, relative frequency of occurrence

which is more than 0.005. Selected relays were tested for wear resistance contacts. After the tests, the average number of operating cycles for all investigated relays was 41140, while the relays of the first group - 27661. 73% of the relays have a operating time less than 41140, and one relay does not correspond to the specifications for this type of relay (operating time less than 104 cycles).

Thus, the economic effect

from the introduction of this method arises due to an increase in the reliability of radio equipment, an increase in the performance of the relay control.

Claims (1)

Invention Formula Predictive test method and control of the quality of electromagnetic relays, which consists in applying to the winding of the relay a voltage pulse sufficient for triggering the relay, measuring the time parameters of the relay and comparing them with statistically determined norms for these parameters, characterized in that, in order to reduce labor intensity and increase the reliability of control, they control a group of electromagnetic relays, on whose windings a series of voltage pulses are applied with a frequency-repetition frequency not exceeding the maximum switching frequency for of this type of relay, during each control pulse from the series, with a sampling interval of time is interrogated, the state of the contacts of the relay group in the time interval from time t to ha from the beginning of the supply of the control pulse, where ri and yy are the minimum and maximum response times statistically determined for each type of relay, memorize the state of the relay contacts and determine response time and bounce time for each relay, and at the end of a series of control pulses: the limit of each relay is the average response time, the average bounce time, the standard deviation of the response time, average cpvzf I/  N Jdtpe / ie type RES-WOC -40 -20 0 20 BUT 60 80 Pus.J & T, px f wo 120 t 160 that