CN203012019U - Relay dynamic resistance on-line detection apparatus - Google Patents

Abstract

A relay dynamic resistance on-line detection apparatus relates to an electrical device detection apparatus, and the provided relay dynamic resistance on-line detection apparatus is simple in structure, convenient in utilization, and suitable for being used by matching with a production line. The relay dynamic resistance on-line detection apparatus comprises a control switch, a signal generation circuit, a current sensor, a signal conditioning circuit, a microcontroller, a display circuit, a communication circuit, an operation button, and a power supply circuit, wherein the control switch is used for controlling on-off states of a relay to be tested; an output terminal of the control switch is connected with an input terminal of the signal generation circuit; an output terminal of the signal generation circuit is connected with an input terminal of the current sensor; an output terminal of the current sensor is connected with an input terminal of the signal conditioning circuit; an output terminal of the signal conditioning circuit is connected with an input terminal of the microcontroller; output terminals of the microcontroller are respectively connected with an input terminal of the control switch and an input terminal of the display circuit; the communication circuit is in bidirectional connection with the microcontroller; an output terminal of the operation button is connected with another input terminal of the microcontroller; and an output terminal of the power supply circuit is connected with another input terminal of the microcontroller.

Description

A kind of relay dynamic resistance on-line measuring device

Technical field

The utility model relates to the electric device pick-up unit, especially relates to a kind of relay dynamic resistance on-line measuring device supporting with production line.

Background technology

At present the method for commonly used several busy relays contact contact resistance has standard law, four-end method and double bridge method.The method of mentioning in standard is used voltage table or reometer, is mainly to utilize manually relay is detected, and is applicable to sampling check, is not suitable for detecting on production line.The four-end method method of testing is applicable to carry out under little current conditions, because large electric current will cause contact temperature to raise, measures the resistance of coming bigger than normal.There is the problem same with four-end method in the double bridge method, and needs to adjust arm resistance, also is not suitable for detecting on production line.Because the dynamic process of contact resistance is of short duration, said method all is difficult to realization to the detection of dynamic resistance.Whether the contact resistance of relay is to affect whether one of the most important factor of reliably working of relay, needs in process of production each product is tested, check its contact resistance or contact voltage drop to meet the requirements.In addition, the contact resistance peak-average ratio contact of not losing efficacy in inefficacy contact is much larger; Therefore the maximal value of contact resistance detected, also extremely important.

At present, how to realize on production line that online detection has become in the industry very problems of concern to the relay dynamic resistance.

Summary of the invention

It is simple in structure, easy to use that the purpose of this utility model is to provide, and is fit to and the matching used a kind of relay dynamic resistance on-line measuring device of production line.

The utility model comprises gauge tap, signal generating circuit, current sensor, signal conditioning circuit, microcontroller, display circuit, telecommunication circuit, operation push-button and power circuit;

Gauge tap is used for controlling the break-make of relay to be measured, gauge tap output termination signal generating circuit input end, signal generating circuit output termination current sensor input end, current sensor output termination signal conditioning circuit input end, signal conditioning circuit output termination microcontroller input end, the microcontroller output terminal connects respectively gauge tap input end and display circuit input end, telecommunication circuit is connected with microcontroller is two-way, operation push-button output termination microcontroller input end, power circuit output end connects the microcontroller input end.

Described gauge tap preferably adopts contactless metal-oxide-semiconductor switch.

Described current sensor, can adopt model is ACS713ELCTR-20A, range is the current sensor of unidirectional 20A.

Described telecommunication circuit can adopt the UART Asynchronous Serial Communication Circuit, and telecommunication circuit can be used for realizing between microcontroller, the data transmission between microcontroller and other PCs.

Described microcontroller can adopt single-chip microcomputer.

Described display circuit preferably adopts liquid crystal display.

Compared with the prior art, the utlity model has following advantage:

Can obviously reflect peak value and the stationary value information of relay dynamic resistance by the electrical quantity of signal generating circuit, information is easily extracted.Because the utility model dynamic process is very of short duration, response is fast, can detect at the utmost point peak value and the stationary value of relay contact dynamic resistance in the short time, so is adapted at that on production line, automatical and efficient rate detects.The utility model is based on a pick-up unit of microcontroller, and it is under the jurisdiction of the vibration cycles test machine 60 times, is serially connected on the relay automatic assembly line.Contacts status when the utility model moves with disconnection to the adhesive of vehicle relay is carried out online qualitative detection, and it is qualified to judge whether, and then and mechanical component, the cooperation of PLC control section is screened.

when the utility model uses, when relay to be measured enters the check point of being located on production line, at first send control signal by microcontroller, gauge tap is opened accordingly and is disconnected, realize energising and the outage of relay coil, signal generating circuit produces peak value and the stationary value that can reflect in dynamic resistance, then be linked into current sensor, current sensor is connected to the contact circuit of coil, current sensor is linked into signal conditioning circuit with the signal that collects, signal is linked into microcontroller after conditioning, show by display circuit (display screen).

Description of drawings

Fig. 1 is the schematic block circuit diagram of the utility model embodiment.

Fig. 2 is for carrying out the circuit block diagram that dynamic resistance detects to the relay that only comprises normally opened contact.

Fig. 3 is the utility model embodiment when detecting, the oscillogram of signal generating circuit.In Fig. 3, (a) for microcontroller provides periodic square-wave voltage figure, horizontal ordinate is the time, and ordinate is voltage; (b) be the variation diagram of relay contact resistance, horizontal ordinate is the time, and ordinate is contact resistance value; (c) be R in Fig. 2 ₁The current waveform figure of branch road, horizontal ordinate are the time, and ordinate is electric current; (d) be C, R in Fig. 2 ₂The current waveform figure of branch road, horizontal ordinate are the time, and ordinate is electric current; (e) be figure R ₁With C, R ₂The electric current sum of two branch roads, horizontal ordinate are the time, and ordinate is electric current.

Embodiment

The utility model is described in further detail below in conjunction with accompanying drawing and example.

Referring to Fig. 1, the utility model embodiment comprises gauge tap 1, signal generating circuit 2, current sensor 3, signal conditioning circuit 4, microcontroller 5, display circuit 6, telecommunication circuit 7, operation push-button 8 and power circuit 9.

Gauge tap 1 is used for controlling the break-make of relay to be measured; Gauge tap 1 output termination signal generating circuit 2 input ends, signal generating circuit 2 output termination current sensor 3 input ends, current sensor 3 output termination signal conditioning circuit 4 input ends, signal conditioning circuit 4 output termination controller 5 input ends, microcontroller 5 output terminals connect respectively gauge tap 1 input end and display circuit 6 input ends, telecommunication circuit 7 is connected with microcontroller 3 is two-way, operation push-button 8 output termination controller 3 input ends.

Described gauge tap 1 adopts contactless metal-oxide-semiconductor switch.It is the current sensor of ACS713ELCTR-20A that described current sensor 3 adopts model.Described telecommunication circuit 7 adopts the UART Asynchronous Serial Communication Circuits, and telecommunication circuit can be used for realizing between microcontroller, the data transmission between microcontroller and other PCs.Described microcontroller 5 adopts single-chip microcomputer.Described display circuit 6 adopts liquid crystal display.

Referring to Fig. 2, when the utility model embodiment detected, gauge tap 1, signal generating circuit 2, current sensor 3 only comprised normally opened contact with relay P(to be measured) jointly form the dynamic resistance testing circuit.In Fig. 2, K is the coil of relay P.R _xBe relay P normally opened contact contact resistance, C, R ₂Form differentiating circuit, R ₁Be ratio circuit, and provide discharge path for the differential path.Adopt contactless metal-oxide-semiconductor IRF540 conducting and cut-off to realize switch, by the signal controlling that microcontroller sends, control accordingly by the photoelectric coupling metal-oxide-semiconductor, realize energising and the outage of relay coil.

Referring to Fig. 3, be the square-wave voltage U of T for being provided for relay coil to be measured in the cycle _N, the correlation parameter waveform as shown in Figure 3.

(1) rigidly connect when contacting when relay sound contact, closing of circuit, generation current, at this moment the relay contact resistance is maximal value R _MAX, because voltage on electric capacity can not suddenly change, this moment U _C=0, each branch current is:

$i_1=\frac{U}{R_{\mathrm{MAX}}+(R_1//R_2)}\·\frac{R_2}{R_1+R_2}---(2-9)$

$i_2=\frac{U}{R_{\mathrm{MAX}}+(R_1//R_2)}\·\frac{R_1}{R_1+R_2}---(2-10)$

Maximal value I appears in electric current I _MAX:

$I=I_{\mathrm{MAX}}={\mathrm{<figure-callout\; id="1"\; label="i"\; filenames="HDA00002752796100011.png"\; state="\{\{state\}\}">i</figure-callout>}}_1+i_2=\frac{U}{R_{\mathrm{MAX}}+({\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA00002752796100011.png"\; state="\{\{state\}\}">R</figure-callout>}}_1//R_2)}---(2-11)$

(2) electric capacity begins charging, i afterwards ₁Diminish gradually.The contact contact resistance also diminishes gradually, and after the steady closure of contact, electric capacity charged already and completed this moment, and at this moment the relay contact resistance is R _W, this moment, circuital current was I _W:

$I=I_W={\mathrm{<figure-callout\; id="1"\; label="i"\; filenames="HDA00002752796100011.png"\; state="\{\{state\}\}">i</figure-callout>}}_1=\frac{U}{R_W+R_1}---(2-12)$

(3) after coil blackout, the contact separates, at this moment R ₁, R ₂, C consists of discharge circuit, but I=0.

By above-mentioned analysis and oscillogram as seen, the peak I of current waveform _MAXWith stationary value I _WCan reflect dynamic contact resistance R _xIn peak value R _MAXWith stationary value R _W

Can get according to formula (2-11), (2-12):

$R_{\mathrm{MAX}}=\frac{U}{I_{\mathrm{MAX}}}-\frac{R_1{R}_2}{R_1+R_2}---(2-13)$

$R_W=\frac{U}{I_W}-R_1---(2-14)$

Obviously, by detecting electric current I, just can obtain easily R _MAX, R _WInformation, realize that the relay dynamic resistance detects.

This shows, the electrical quantity of signal generating circuit can obviously reflect peak value and the stationary value information of relay dynamic resistance to be measured, and easily extracts, and can detect parameter information by current sensor.The controller part is mainly completed the closed control with disconnecting of gauge tap in the relay test process; Judgement to the signal processing output signal; With communicating by letter of PLC, complete production line automation equipment to clamping and the rejecting of relay to be checked; Control the LCD output display.Control section is mainly to be the control system that core consists of by the ATMAGE16L microcontroller.Communications portion, the UART asynchronous serial communication is a kind of communication pattern that single-chip microcomputer is often used, in the utility model teachers and students example, all complete by this unit with communicating by letter of PLC or LCD display curtain, the utility model can automatically be coordinated PLC and carry out relay test, can carry out type of detection and select, and on liquid crystal display with close friend's showing interface detected state and result.

Claims (6)

1. a relay dynamic resistance on-line measuring device, is characterized in that comprising gauge tap, signal generating circuit, current sensor, signal conditioning circuit, microcontroller, display circuit, telecommunication circuit, operation push-button and power circuit;

Gauge tap is used for controlling the break-make of relay to be measured, gauge tap output termination signal generating circuit input end, signal generating circuit output termination current sensor input end, current sensor output termination signal conditioning circuit input end, signal conditioning circuit output termination microcontroller input end, the microcontroller output terminal connects respectively gauge tap input end and display circuit input end, telecommunication circuit is connected with microcontroller is two-way, operation push-button output termination microcontroller input end, power circuit output end connects the microcontroller input end.

2. a kind of relay dynamic resistance on-line measuring device as claimed in claim 1, is characterized in that described gauge tap adopts contactless metal-oxide-semiconductor switch.

3. a kind of relay dynamic resistance on-line measuring device as claimed in claim 1, is characterized in that it is ACS713ELCTR-20A that described current sensor adopts model, and range is the current sensor of unidirectional 20A.

4. a kind of relay dynamic resistance on-line measuring device as claimed in claim 1, is characterized in that described telecommunication circuit adopts the UART Asynchronous Serial Communication Circuit.

5. a kind of relay dynamic resistance on-line measuring device as claimed in claim 1, is characterized in that described microcontroller adopts single-chip microcomputer.

6. a kind of relay dynamic resistance on-line measuring device as claimed in claim 1, is characterized in that described display circuit adopts liquid crystal display.

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