CN2218380Y - Intellectual protecting switch - Google Patents

Abstract

The utility model relates to an intellectual protecting switch which is used for monitoring a measuring apparatus. The utility model is mainly characterized in that the utility model comprises a set of sensors, a signal conversion circuit, three sets of mutually independent computers, a control relay and a drive circuit. The drive circuit is a data coupling drive circuit which is formed by three transistors and a biasing circuit, so the relay can be driven. The utility model has the advantage of simple structure. When the utility model is used, the normal work of the relay can be assured so long as the two-way signal is provided; thus, the high reliability of a measuring instrument is guaranteed.

Description

The intelligent protection switch

The utility model relates to telltale, is the intelligent protection switch instrument in a kind of control measurement device.

Along with the widespread use of single chip microcomputer technology in instrument; numerous intelligentized measurement instruments have appearred; as in the thermal parameter surveillance device of power station as the temperature protection switch of control measurement power plant auxiliary machine bearing temperature; it is the closure of coming pilot relay with single-chip microprocessor system, realizes the purpose of reporting to the police when reaching the temperature exceeds setting value.This intelligentized temperature protection switch includes a sensor, one non electrical quantity is converted to the bridge-type change-over circuit of electric weight, signal conditioning circuit, a voltage/frequency change-over circuit (VFC); the computer system that one cover is made of CPU element (central processing unit) and peripheral circuit thereof, a driving circuit and a relay that constitutes with gate circuit, switch case panel be provided with digital displaying window, pilot lamp and be connected with computer system include setting value, inspection, accident record, cancellation, recovery, the button of function such as show, reply.This smart instrumentation, the signal of its sensor converts voltage signal to after being input to bridge circuit, convert the voltage standard signal to through signal conditioning circuit again, convert this voltage signal to certain frequency signal by the VFC circuit again, import computer system then, convert corresponding numerical signal to by CPU, and this measured value and the numeric ratio set, automatically judge whether measured value surpasses setting value, when measured value continuous when out-of-limit in the delay time of setting, computing machine then sends the contact actuating signal, makes relay carry out closed procedure (concerning normally opened contact) through driving circuit, sends the warning that overflows.In general, the intelligent measuring instrument all there is the requirement of high reliability, but, existing this type of instrument is because of being subjected to the restriction of CPU integrated circuit and the reliability of peripheral circuit own thereof, the reliability of the instrument of its composition is also just relatively poor, in case these a certain circuit that constitute computer systems break down or when power fail took place, instrument " false newspaper " will occur, refuse to submit or become deadlock, make that control measurement is inaccurate maybe can't to carry out.For improving reliability, someone proposes to adopt three to overlap mutually independently computing machine, and design special software package and realize control, same input signal is imported in the three cover computing machines simultaneously, three cover computing machines are worked separately, all identical or when having two signals identical, actuating relay just moves when the output signal of three cover computing machines.Here it is three gets two judgement schemes.But the software package in this design proposal is complicated, needs computing machine to have enough storage spaces, is not suitable for single-chip microcomputer, so price is expensive.

The purpose of this utility model is for a kind of improved intelligent protection switch is provided, and makes it as long as can realize control with single-chip microcomputer, and has enough reliabilities, even a certain circuit of computer system breaks down, switch still can be worked exactly.

The utility model of realizing above-mentioned purpose is, the same with prior art, also include a sensor, a bridge circuit that non electrical quantity is converted to electric weight, a signal conditioning circuit, a VFC circuit, the computing machine that three covers independently are made of cpu central processing unit and peripheral circuit thereof mutually, a driving circuit and a relay, the switch case panel is provided with digital displaying window, pilot lamp and assortment of keys, characteristics of the present utility model are, driving circuit is for including one by three transistor T1, T2, the data lotus root of T3 and biasing resistor separately thereof is closed driving circuit, wherein, the biasing resistor of emitter is connected in series with the inclined to one side resistance of collector, the point of contact of two resistance is connected with the base stage of other one-level triode, three triode T1, T2, the emitter while of T3 is electrically connected with the input end of relay.This data coupling circuit also claims three to get two relay drive circuits, after three cover computing machines are according to same input signal operation, input end to driving circuit sends actuating signal when (even the input end of driving circuit is low level) simultaneously, and relay produces action; Any two machines send under the situation of actuating signal in three machines, and relay also produces action, and when having only a machine to send under the situation of actuating signal (all the other two machines break down) in three machines, relay does not produce action.

Therefore, the utility model has the advantages that, as long as use a data lotus root that constitutes by three triodes to close driving circuit, can realize that three get two controls.The utility model is simple in structure, the functional reliability height, its duty is, the signal that sensor sensing arrives is after same group of signal processing circuit handled, import three simultaneously and overlap mutually independently computer system, import the action that same driving circuit removes pilot relay again after three cover computer systems are moved independently of one another.If three cover computing machines all move normally, perhaps there is a cover computing machine to break down, also have two cover computing machines in operation, then relay still can normally be carried out, and has only when three and overlaps when having two to overlap computing machines fault is arranged in the computing machines relay and just do not work.Generally speaking, can there be two cover computing machines to damage simultaneously, and have only a cover computing machine when breaking down, can not influence the operate as normal of instrument, because, when the unit fault takes place when, trouble light meeting prompting changing parts on the panel, with the normal operation continuously of assurance instrument, so, the utlity model has higher reliability

Embodiment of the present utility model as shown in drawings.Below in conjunction with the accompanying drawing illustrated embodiment the utility model is described specifically.

Description of drawings:

Fig. 1 is a machine system pie graph of the present utility model;

Fig. 2 is the system diagram of used computer system in the utility model;

Fig. 3 closes the circuit diagram of driving circuit for data lotus root in the utility model;

Fig. 4 is a structural representation of the present utility model;

Fig. 5 is a panel layout of the present utility model.

At first see also Fig. 1.Embodiment illustrated in fig. 1 is a kind of intelligent temperature protection switch, and its sensor 1 is a temperature sensor, and this temperature sensor can be a thermal resistance, also can be thermopair.Temperature sensor 1 is input to bridge-type change-over circuit 2 after sensing temperature signal, this circuit is varied to thermal signal the standard signal that converts 0-10V behind certain voltage signal again through signal conditioning circuit 3 to, convert this voltage signal to certain frequency signal by voltage/frequency change-over circuit 4, this imports mutually independently three cover computing machines 5 simultaneously by the converted frequency signal of temperature signal, 6,7, three cover computing machines are separately behind the independent operating, convert three corresponding temperature signals to and carry out comparing with desired temperature, automatically judge whether observed temperature crosses setting value, if when observed temperature continuous when out-of-limit in the delay time in setting, the plan machine then sends contact actuating signal (promptly presenting low level), three machines 5,6,7 three contact actuating signals sending are closed 9 actions of relay of rear drive through data coupling circuit 8 lotus roots.Computing machine in the present embodiment adopts branch system as shown in Figure 2, it includes a central processing unit 10 (CPU monolithic) and by EPROM storage circuit 13, automatic reset circuit 11, display circuit 14, keyboard input circuit 12, the peripheral circuit that power circuit and bus constitute, in this computer system, import the design temperature upper limit by the button 14 that is arranged on the panel 11, the upper limit, time delay, dead band temperature etc., and, utilize the display screen of button and computer system that setting value is checked, to check above-mentioned setting value, accident record reaches demonstration in turn etc.

Data lotus root in the present embodiment is closed driving circuit as shown in Figure 3, this circuit is for going out three triode T1, T2, T3 and biasing resistor R11 thereof, R12, R21, R22, R31, R32 constitutes, R11, R12 is the biasing resistor of the emitter and collector of triode T1, equally, R21, R22 is the biasing resistor of T2, R31, R32 is the biasing resistor of T3, resistance R 11 and R12 are connected between the emitter and collector of triode T1, R11, the point of contact A of R12, and R21, the point of contact B of R22, R31, the point of contact C of R32 respectively with three triode T3, T1, the base stage of T2 is connected; Output terminal a, b, the c of three cover computing machines are connected with the collector of three triode T1, T2, T3 respectively, and the emitter of three triodes is electrically connected with the input end P of relay 9 simultaneously.This data lotus root is closed driving circuit and has three kinds of duties:

1, three cover computing machines 5,6,7 all send actuating signal, be that a, b, 3 of c are low level, then all there is electric current to flow through among the R11-R32, A, B, C three points of contact produce certain voltage, make the base stage of triode T1, T2, T3 produce certain voltage, and the pressure drop between triode T1 collection, the emitter-base bandgap grading at this moment equal R11, the pressure drop of R12 two ends, like this, triode T1 conducting; In like manner, also conducting of T2, T3, the feasible electric current I=I1+I2+I3 that flows through the coil of relay 9 enough drives relay 9 actions.

Any two machines send actuating signal in 2, three machines, suppose that computing machine 5,6 sends actuating signal, machine 7 does not send actuating signal (the c point is a high level), and then R31, R32 no current flow through, and voltage is zero between T3 collection, the emitter-base bandgap grading, no current flows through, and c point current potential equals P point current potential, not conducting of T2; T1 collection, emitter voltage equal (R11+R12) both end voltage, and forward bias voltage equals the R21 both end voltage, the T1 conducting, and the electric current that then flows through triode is enough to drive relay 9, makes it action.

3, have only a machine to send actuating signal in three machines, postulated mechanism 5 sends actuating signal (a is a low level), and 6,7 liang of machines of machine do not send actuating signal (a, b point is a high level), then T2, all not conductings of T3, equal no current flows through among R21, R22 and R31, the R32,2 electricity of B, C equal the P point voltage, make not conducting of T1, have electric current to flow through among the R11+R22 and have only this moment, because R11, R12 resistance are bigger, the electric current that flows through R11, R12 is

(wherein, Rj is the coil resistance of relay 9, and I inhales and is the minimum operate current of relay 9) then this driving circuit can't drive the action of relay 9.

The structure of present embodiment is (remove shell and front and back panels after inner structure synoptic diagram) as shown in Figure 4.See by figure, framework 19 front ends be one its be provided with the display board 15 of charactron, framework 19 rear portions are two block power supply plates, one is utility power plate 18, another piece is a computer power supply plate 20, and framework 19 inside are inserted with 16,21 and three computer main frame panels 17 of signaling conversion circuit plate.The panel that is fixed on framework 19 front ends as shown in Figure 5, it is provided with display window 23, six malfunction indicator lamp 22 and 15 buttons 24.Display window 23 is positioned at the charactron position, button 24 is in order to be provided with passage, the upper limit of temperature, the last upper limit, delay time, dead band temperature are set and checked to computing machine 5,6,7, and also available accident record key wherein comes the inspection accident, cancel passage or recover passage with cancel key, resetkey, show each channel temperature value or apparent and left alone without help the staying on a certain passage of halt wheel in turn with taking turns apparent/halt key, remove to remove accident record with listening key; The effect of the malfunction indicator lamp on the panel is, if have when accident occurring that observed temperature surmounts in limited time, when having one to break down in three machines, when computer action breaks down, when power supply breaks down or sensor when breaking down, relevant pilot lamp is promptly bright, goes to repair with reminds people.More than the setting and the function of these keys, lamp all be the universal design of computer hardware, be not the place of the characteristics of present embodiment, at this only for making the public can more clearly understand the generality explanation that the utility model is done.

The utility model is as long as the different sensor of transposing as liquid level sensor, pressure transducer or flow sensor, just can be formed the intelligent protection switch of monitoring different physical quantities.

Claims (1)

1, a kind of intelligent protection switch, include sensor, a bridge circuit that non electrical quantity is converted to electric weight, a signal conditioning circuit, a voltage/frequency change-over circuit, the computer system that three covers independently are made of cpu central processing unit and peripheral circuit thereof mutually, a driving circuit, one relay, the panel of switch case is provided with digital displaying window, pilot lamp reaches the setting value that includes that is connected with computer system, check, accident record, cancellation, recover, show, the button of function such as reply, it is characterized in that said driving circuit is for by three triode T1, T2, T3 and biasing resistor R11 thereof, R12, R21, R22 and R31, the data lotus root that R32 constitutes is closed driving circuit; R11 and R12 are connected between the emitter and collector of triode T1, R21 and R21 are connected between the emitter and collector of triode T2, R31 and R32 are connected between the emitter and collector of triode T3, the point of contact A of R11, R1 2, the point of contact B of R21, R22 and the point of contact C of R31, R32 are connected with the base stage of three triode T3, T1, T2 respectively, and the emitter of three triode T1, T2, T3 is connected with the input end P of relay 9 simultaneously.

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