CN1024480C

CN1024480C - Monitoring instrument for dynamic contact failure of contactors

Info

Publication number: CN1024480C
Application number: CN 90103996
Authority: CN
Inventors: 郝秉珍; 包思云
Original assignee: Forty-First Inst Ministry Of Machine-Building And Electronics Industry (cn
Current assignee: Forty-First Inst Ministry Of Machine-Building And Electronics Industry (cn
Priority date: 1990-05-28
Filing date: 1990-05-28
Publication date: 1994-05-11
Anticipated expiration: 2005-05-28
Also published as: CN1057111A

Abstract

The various existing monitor contact monitoring instruments whose elements have dynamic contact failures have disadvantages of poor anti-interference capability, poor stability, poor conformity, etc. and have low monitor precision. The monitoring instrument provided by the present invention uses digital time comparison technique. The lines are composed of a time base signal generating circuit, a time discrimination circuit, an amplitude discrimination circuit and an alarming and displaying circuit. The circuit has favorable anti-interference performance and high monitoring precision, and can display monitoring results, such as failure duration, failure times, etc. in a digital form. The monitoring instrument can be widely used for dynamic contact failure monitor of elements, such as connectors, relays, switches, etc.

Description

Monitoring instrument for dynamic contact failure of contactors

The invention provides the dynamic contact fault monitor of a kind of monitoring contact class component, belong to a kind of electronic gauge.

Mechanical contact can produce under the dynamic effect in the external world that the circuit-closing contacts wrong diagnosis is held or the mistake closure of contact, and this phenomenon is called dynamic contact fault.For the system that the contact class component is controlled, dynamically contact fault is very harmful.So, all to stipulate in the mechanical environment process of the test, will monitor contact fault in the test standard of nearly all contact class component and whether exceeded setting, this is the important symbol that ensures the q﹠r of contact class component.

Contact fault appears in existing both at home and abroad various monitoring contact class component in the mechanical environment process of the test method mostly adopts the charge-discharge circuit of resistance-capacitance type to produce referential standard time at interval, be used for comparing with fault-time, the shortcoming of sort circuit is a poor anti jamming capability, be subjected to the influence of temperature, time bigger, stability, consistance is all relatively poor, because the accumulation of electric charge also is easy to generate erroneous judgement on the electric capacity, cause monitoring accuracy low, the development of electronics industry at present is more and more high to the requirement of contact class component, and original monitor can not adapt to.

The object of the present invention is to provide a kind of observation circuit that adopts digital amount control, the dynamic contact fault that monitoring contact class component occurs in the mechanical environment test.

The monitor of the dynamic contact fault of monitoring contact class component provided by the present invention, form by instrument panel, switch, display element, the electronic circuit be located on the panel, its electronic circuit comprises power circuit, constant-current source circuit, alarm indication circuit, also is provided with the time-base signal generation circuit of being made up of 10MHZ crystal oscillator, frequency divider, storage circuit able to programme and data selector on the line; The fault amplitude comparator circuit that constitutes by voltage comparator; Discriminator circuit fault-time that is composed in series by two decade counters; Be input to the fault-time discriminator circuit by the time-base signal of time-base signal generation circuit output and pulse signal and compare, relatively back output carry signal or send Display and Alarm Circuit from reset signal by the output of fault amplitude discrimination circuit.The set Display and Alarm Circuit of this instrument is by the trouble duration display circuit of being made up of d type flip flop, AND circuit, latch and decoding, driving, display; Make number of stoppages statistical circuit and the display circuit that triggers element by d type flip flop with door, number of stoppages statistical circuit is made up of secondary decimal counter, decoding, driving, display; Display circuit comprises the driving circuit that d type flip flop, resistance, transistor are formed and places light emitting diode on the transistor collector.

Figure of description:

1. the functional-block diagram of dynamic contact fault monitor provided by the present invention.

2. the functional-block diagram of dynamic contact fault monitor time-base signal generation circuit provided by the present invention.

3. fault amplitude discrimination circuit schematic diagram in the dynamic contact fault monitor provided by the present invention.

4. in the dynamic contact fault monitor provided by the present invention fault-time the discriminator circuit schematic diagram.

5. contact fault duration display circuit schematic diagram in the dynamic contact fault monitor provided by the present invention.

6. contact fault number of times statistics and failure indicating circuit schematic diagram in the dynamic contact fault monitor provided by the present invention.

7-14 is dynamic contact fault monitor embodiment provided by the present invention.

7. power circuit diagram

Fig. 7-a provides+the 5V power circuit diagram

9N ₁: three terminal regulator 7805

9N ₂: three terminal regulator 7805

Fig. 7-b provides-the 5V power circuit diagram

9N ₃: three terminal regulator 7905

Fig. 7-c provides+the 10V power circuit diagram

9N ₄: three terminal regulator LM371

Fig. 8 constant-current source circuit

Wherein: 6N _1-13Three terminal regulator LM371

Fig. 9 time-base signal generation circuit theory diagrams

1D ₁74LS14

1D ₂EPROM2716

1D ₃Eight select a data selector 74LS1S1

1D ₄Eight impact damper 74LS367

1D ₅High speed phase inverter 74F04

1D ₆～1D ₉Counter 74LS192

1D ₁₀Eight impact damper 74LS367

10. fault amplitude discrimination circuit schematic diagram

4D _1,3-8Hex inverter 74LS04

4D _2-3Four or two inputs or door 74LS32

4N ₁Simulate switch CD4052

4N ₂Simulate voltage comparator LM361N

11.2 attenuator doubly

Wherein, 5V _1-12, 2AP ₅

12. fault-time discriminator circuit and number of stoppages statistical circuit

Wherein: 2D _{1,2,4,5,7,8,10,11,13,14,16,17}Counter 74LS192

2D _{3,6,9,12,15,18}BD latch 74LS373

13. latch signal produces circuit

Wherein: 3V _1-7Switch triode 3DK2C

3D _1,6,7,8,16Integrated double D trigger 74LS74

3D _5,9,15High speed d type flip flop 74F74

14. display board

Wherein: 8V _1,3,5,7,9,11Triode 3DK2C

8V _2,4,6,8,10Light emitting diode BT205

8D ₁Three inputs or door CD4075

8D _2,5Hex inverter 74LS04

8D _3,6Four inputs or door 74LS21

8D

_7-147 sections luminous digital LDD680R

Be described below below in conjunction with the operation principle of accompanying drawing with each circuit:

Fig. 2 is time-base signal circuit for generating schematic diagram, square-wave signal, this signal of being produced 10MHZ by the 10MHZ crystal oscillator are input to data selector through the fractional frequency signal that level Four ten frequency divider frequency divisions produce with the control signal that Programmable Memory takes place, and deliver to discriminator circuit fault time by the required time-base signal of data selector output.

Fig. 3 is a fault amplitude discrimination circuit frame principle figure, discriminator circuit is made of voltage comparator, the down pulse of measured piece is added to the in-phase input end of voltage comparator, reference voltage is added in the inverting input of voltage comparator, when the amplitude of down pulse voltage surpassed reference voltage, a width and input fault pulsion phase fault-signal were together carried in the comparer upset, when the amplitude of false voltage is lower than reference voltage, just non-fault occurs, and comparer is output as low level.

Fig. 4 is discriminator circuit schematic diagram fault-time, this circuit is in series by two decade counters, the data terminal of two counters all connects and is low level, the time-base signal that fault-signal of sending here from the fault amplitude discrimination circuit and time base circuit are sent here is sent into two input ends of time-discriminating circuit respectively, when down pulse is imported, input high level is counted counter, because test fault-time of regulation contact class component is divided into 1US among the GB5095,10US, 100US, 1MS, five grades of 10MS, when input end is come in the 10th the time main pulse, by carry pulse of counter output to the next stage counter, as long as observe counter whether carry pulse output is arranged, whether the duration that just can judge contact fault exactly exceeds requirement.Because of all connecing, the data terminal of all counters in the circuit is low level, so during non-fault, output also is low level, has promptly played the effect of zero clearing.

Figure 5 shows that the display circuit of contact fault duration, this circuit is by producing the latch enable signal of latch with door and d type flip flop, when carry pulse appears in counter, when the negative edge of fault arrives, send a signal triggering d type flip flop with door, send driving, decoding, display to show with its low level output terminal as the latch signal of latch and the numerical value that latchs counter, its displayed value is trouble duration, when trouble duration is lower than standard, because counter no-output event display will not show.

Figure 6 shows that number of stoppages statistical circuit and display circuit, two circuit are both by d type flip flop and AND circuit and make the triggering element, when triggering d type flip flop generation trigger pip, the down pulse arrival makes the statistical circuit counting, down pulse counter of every mistake is just counted once, per 10 down pulses are come, first order counter is just exported a carry pulse to second level counter, send latches after the rolling counters forward after, send decoding, display circuit to show.This circuit is made trigger pulse with down pulse, makes zero clearing usefulness again simultaneously, and the negative edge of down pulse makes the d type flip flop zero clearing, thereby the number of counters count is equated with the number of stoppages.After door and pulse of d type flip flop generation, the d type flip flop that goes again to trigger in the display circuit forms a stable high level, makes transistor turns, the lumination of light emitting diode indication.

Dynamic fault monitor provided by the present invention has adopted full digital comparison fault-time technology, and measurement results such as the trouble duration and the number of stoppages can have been shown with digital form.This monitor good in anti-interference performance, the measuring accuracy height can qualitative, quantitatively show measurement result, can be widely used in the contact fault monitoring of elements such as various connectors, relay, switch.

Below again further combined with description of drawings enforcement of the present invention, dynamic contact fault monitor provided by the present invention, its manufacture craft flow process is same as general electronic measuring instrument, and Fig. 7-14 is each embodiment of circuit figure of detector.Present embodiment, be provided with 12 passages, Fig. 7 a-c is power supply circuit board figure, it provides each circuit board of this instrument required voltage, Fig. 8 is constant current source figure, constant current source also divides 12 road outputs, form by three-terminal voltage regulator LM317 and potentiometer, each road output is 100mA, Figure 9 shows that time-base signal generation circuit, adopt 10MHZ crystal oscillator, the 2716EPROM circuit that memory able to programme adopts in the circuit, do level Four frequency division usefulness with four counter 74LS192, the 74LS151 that data selector is selected for use is selected in a data selector.Figure 10 fault amplitude discrimination circuit, since in GB5095.1-85 regulation fault amplitude greater than the voltage electromotive force 50% for breaking down, adding power supply voltage in the present embodiment is 10V, so as tested false voltage surpasses 5V, promptly be judged to and break down, selected analog voltage comparator LM361N in the present embodiment for use, the reference voltage that is added on the inverting input is+2.5V, former with the first in-phase input end that after 2 times of attenuators decay shown in Figure 11, is added to comparer again of tested false voltage, contact fault when having output, comparer has taken place.Figure 12 is a discriminator circuit and number of stoppages statistical circuit fault-time, wherein fault-time discriminator circuit counter adopt two 74LS19Z2 decimal counters to be in series, its data terminal all connects and is low level, time-base signal is imported from 5 pin, false voltage is imported from 11 pin, and carry pulse is exported from 12 pin.The display circuit of trouble duration produces circuit with Figure 13 latch signal, produces latch enable signal by 74LS74 double D trigger and 74L,S08 42 inputs with door, by the signal of 74LS08 latches counter.Latch signal send display board circuit shown in Figure 14 to show.Number of stoppages statistical circuit adopts decade counter 74LS192 to be in series in the present embodiment, send display board to show behind the counting.

Claims

1, a kind of monitor of monitoring the dynamic contact fault of contact class component, form by instrument panel, switch, display element, the electronic circuit be located on the panel, its electronic circuit comprises power circuit, constant-current source circuit, alarm indication circuit, and the spring is characterised in that on the circuit and also is provided with;

(1) the time-base signal generation circuit of forming by 10MHZ crystal oscillator, frequency divider, storage circuit able to programme and data selector, produce square-wave signal by the 10MHZ crystal oscillator, through level Four ten frequency divider frequency divisions, the control signal that this square-wave signal sends with fractional frequency signals at different levels and memory able to programme is input to the required time-base signal of data selector output;

(2) the fault amplitude comparator that constitutes by voltage comparator;

(3) discriminator circuit fault-time that is in series by two decimal counters,

Be input to the fault-time discriminator circuit by the time-base signal of time-base signal generation circuit output and failure pulse signal and compare, relatively back output carry signal or from the reset signal alert display circuit of delivering newspaper by the output of fault amplitude discrimination circuit.

2, monitoring contact class component dynamic fault monitor according to claim 1 is characterized in that warning, the display circuit in the electronic circuit comprises:

(4) the trouble duration display circuit of forming by d type flip flop, AND circuit, latch and decoding, driving, display;

(5) make number of stoppages statistical circuit and the display circuit that triggers element by d type flip flop and AND circuit, number of stoppages statistical circuit is made up of secondary decimal counter, decoding, driving, display; Display circuit comprises the driving circuit that d type flip flop, resistance, transistor are formed and places light emitting diode on the transistor collector.