CN2291738Y

CN2291738Y - Multi-functional electronic protector for electric machine without external electric supply

Info

Publication number: CN2291738Y
Application number: CN 97215538
Authority: CN
Inventors: 金立彬
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-04-28
Filing date: 1997-04-28
Publication date: 1998-09-16
Anticipated expiration: 2007-04-28

Abstract

The utility model relates to a multifunctional electronic protector, which can protect motors when the motors have the faults of starting over-current, running over-current, starting overtime and phase failure without an external power supply. The multifunctional electronic protector is provided with a rectangle box body which is made of plastic; a light-emitting diode indicating lamp, a potentiometer turn knob, a binding post which is connected in series with the coils of a main control AC contactor and a lead through hole which can be passed through by a motor power lead are arranged on the box body; an electronic switch circuit, a power supply circuit, a starting over-current protection circuit, a running over-current protection circuit, a staring overtime protection circuit and a phase failure protection circuit are arranged in the box body. The multifunctional electronic protector is characterized in small size, simple lead connection, convenience and practicability.

Description

The motor multifunction electronic protector of dispense with outer connecting power

The utility model relates to a kind of electronic protection that motor is protected; especially do not need external power supply just can in time play the motor multifunction electronic protector of protection during the fault of the phase failure to motor take place starting overcurrent, operation overcurrent, starting overtimely.

At present, known motor electronic protector must get external power supply could operate as normal, when this external power for some reason the phase failure or during with the conductor cord disconnection of protector external power supply protector quit work because of outage, at this moment motor breaks down and can't play a protective role.Know that again the prior motor electronic protector does not all have the startup current foldback circuit.When motor carries out reduced-voltage starting, because of start-up time long and in start-up time electronic protector do not make current detecting, only after startup enters normal operation, just carry out current detecting.Starter motor causes motor burning in the long-time energising of big electric current because of protector can not detect starting current when the rotor bearing that starts front motor damages or occur making the reason that rotor blocks like this.

The purpose of this utility model provides a kind of dispense with outer connecting power and just can take place start overcurrent, operation overcurrent, can in time play the motor multifunction electronic protector of protection when starting the fault of overtime, the phase failure motor.

The utility model is achieved in that and adopts to mould a system rectangle box body, has on the box body: light emitting diode lamp, potentiometer knob, the binding post that is connected in series with the master control ac contactor coil, can be by the threading hole of motor power-supply wire; In box body, be equipped with by diode; one-way SCR; electric capacity; triode; the electronic switching circuit that voltage stabilizing didoe and resistance are formed; by diode; zener diode; electric capacity; the power supply circuit that Light-Emitting Diode and current transformer are formed; by integrated package; light-emitting diode; voltage stabilizing didoe; potentiometer; resistance; the operation current foldback circuit that electric capacity and current transformer are formed; by integrated package; light-emitting diode; potentiometer; the startup current foldback circuit that resistance and electric capacity are formed; by integrated package; light-emitting diode; zener diode; potentiometer; the startup current foldback circuit that resistance and electric capacity are formed; by integrated package; light-emitting diode; diode; electric capacity; resistance; the overtime protective circuit of startup that potentiometer and triode are formed is by integrated package; triode; diode; voltage stabilizing didoe; resistance; the open-phase protection circuit that electric capacity and current transformer are formed.

Owing to adopt such scheme, can just can take place to start that overcurrent, operation overcurrent, startup are overtime, play a protective role during the fault of the phase failure not connecing external power motor.Convenient and practical good effect is arranged.

Fig. 1 is a profile schematic diagram of the present utility model.Fig. 2 is a circuit diagram.

1 is the rectangle box body among Fig. 1, and there is light emitting diode lamp 3 (LED1, LED2, LED3, LED4 and LED5) on the upper left side on box body; There is potentiometer knob 4 (W1, W2 and W3) lower left on box body; There is the binding post 2 (S1 and S2) that is connected in series with the master control ac contactor coil lower right on box body.Having in the side of box body can be by the threading hole 5 (outer wall in hole is with current transformer LA, LB and LC) of motor power-supply wire.

The power supply be made up of following circuit, and protective circuit are housed in box body 1:

The electronic switching circuit of forming by diode D1-D6, voltage stabilizing didoe DW1, one-way SCR BCR, capacitor C 1-C3, triode BG1-BG3 and resistance R 1-R6.

The power supply circuit of forming by diode D12-D15 bridge rectifier, filter capacitor C7, voltage stabilizing didoe DW4, power supply indicator LED5 and current transformer LC.

By a part of IC1-3 in the ic chip 1 (LM324); operation overcurrent indication LED 3, protection voltage stabilizing didoe DW3, filter capacitor C4, halfwave rectifier diode D7, the operation current foldback circuit that operation overcurrent regulator potentiometer W1, resistance and current transformer LA form.A part of IC1-3 in the ic chip 1 uses as voltage comparator.

By a part of IC1-2 in the ic chip 1 (LM324), phase failure indication LED 2, diode D8-D10, the open-phase protection circuit that current transformer, voltage stabilizing didoe DW3, triode BG5, filter capacitor C5, resistance are formed.A part of IC1-2 in the ic chip 1 uses as voltage comparator.

By a part of IC1-1 in the ic chip 1 (LM324), start overcurrent regulator potentiometer W2, start the startup current foldback circuit that overcurrent indication LED 1, resistance and electric capacity are formed.A part of IC1-1 in the ic chip 1 uses as voltage comparator.

By a part of IC1-4 in the ic chip 1 (LM324), start overtime indication LED 4, discharge diode D11, timing capacitor C6 starts overtime regulator potentiometer W3, the overtime protective circuit of startup that switch triode BG4, resistance are formed.A part of IC1-4 in the ic chip 1 uses as voltage comparator.

The course of work of circuit:

When pressing start button AN, the 380V alternating current constitutes current supply circuit through master control ac contactor coil C and D1-D4 bridge rectifier and R2 (100K), DW1 (7.5V).Because R2 (100K) resistance ambassador contactor coil C can't make the contactor adhesive because of operating current is little, at this moment will there be an alternating current at S1, S2 two ends through the D1-D4 rectifier rectification, the R2 current limliting, there is the stable DC voltage of 7.5V to make its conducting, A.C. contactor C adhesive and self-locking after DW1 voltage stabilizing, the C3 filtering by R4 triggering BCR at the two ends of DW1.When the B point ends BG2 during for low level, at this moment A point (pressure drop of D5 and D6 and) direct current charges to C2 by R2, after 2 seconds charging voltage reach 0.7V when above the BG1 conducting force BCR triggerless electric current and end.Ac contactor coil C forms current supply circuit with R2, DW1 again, because electric current can not make coil C keep adhesive event contactor escape, latching point disconnects and cuts off current supply circuit, reaches the purpose of protection.

Open-phase protection circuit: when the motor operate as normal; the terminals of current transformer LA, the LB of three phase lines, LC all produce the induction alternating current in the threading hole, and wherein LC coil two ends alternating current is done this protector power supply for 7.5V galvanic current source after D12-D15 rectification, DW4 and LED5 voltage stabilizing, C7 filtering.Phase time in disconnected LC, so LC is a low level because of non-inductive alternating current B point, contactor C escape after 2 seconds.Phase time (phase line in LB, the LC threading hole is all normal) in disconnected LA threading hole, at this moment the also non-inductive alternating current in LA current transformer two ends, inverting input 9 pin of IC1 will be low level, in-phase input end 10 pin of IC1 are high voltage (9 pin current potentials are higher than 10 pin current potentials during the bad phase failure of L), so output 8 pin of IC1 output high level (IC1 here is that device is used as a comparison), LED2 lights, the BG3 conducting makes the B point also be low level, contactor escape.Phase time (phase line in LA, the LC threading hole is all normal) in disconnected LB threading hole, the non-inductive alternating current in LB instrument transformer two ends, BG5 is ended, F names a person for a particular job and becomes high level (7.5V) adds to IC1 by D9 10 pin, this moment, 10 pin voltages were 7.5-0.7=6.8V, and the 9 pin voltages of IC1 are 4V (DW3 voltage stabilizing value is 4V), because of 10 pin current potentials are higher than 9 pin current potentials so the 14th pin is just exported high level, make the B point be low level, contactor escape again.

Operation current foldback circuit:, regulate operation overcurrent potentiometer W1 and makes IC1 have 12 pin current potentials to be lower than 13 pin current potentials (3V) when motor during in normal operation.R7, DW2 (6V) play protection 12 pin effects.During as overcurrent in service, the voltage that the LA instrument transformer is responded to raises, and in like manner the 12 pin current potentials of IC1 also raise, when being elevated to the current potential that is higher than the 13rd pin, the 14th pin output high level, operation overcurrent indicator light LED3 is bright to make the BG3 conducting, make the B point be low level, contactor escape.

Start current foldback circuit: just often regulate startup overcurrent potentiometer W2 at starting current and make the 5 pin current potentials of IC1 be lower than 6 pin current potentials, at this moment 7 pin output low levels.To be higher than 6 pin current potentials and make 7 pin output high level when starting current exceeds normal value 5 pin current potentials, start the bright BG3 conducting of overcurrent indicator light LED1, contactor escape after 2 seconds.

Start overtime protective circuit: start overtime protective circuit and start the current foldback circuit cooperating.Regulate and start overtime potentiometer W3 scalable timing; power supply charges to C6 by R22, W3 when firm startup; because the 2 pin current potentials of IC1 are lower than 3 pin current potentials; so 1 pin is exported high level, LED4 is bright; it is low level that the BG4 conducting makes 14 pin, prevents to make the protector misoperation because of starting current is higher than running current.Along with the time 2 pin current potentials that extend of charging raise gradually when be higher than 3 pin current potentials, pin output low level BG4 finishes by starting, and as above start-up time, 14 pin will be exported high level, make the contactor escape.D11 provides the repid discharge loop for C6.

Claims

1, a kind of motor multifunction electronic protector of dispense with outer connecting power is to mould system rectangle box body by one; Having in the side of box body can be by the threading hole of motor power-supply wire, there are the overcurrent of startup indicator light, phase failure indicator light, operation overcurrent indicator light in upper left side on box body, start overtime indicator light, power supply indicator, operation overcurrent regulator potentiometer is arranged in the lower left of box body, start the overcurrent regulator potentiometer, start overtime regulator potentiometer, form by the binding post that is connected in series with the master control ac contactor coil in the lower right of box body; It is characterized in that: in box body, be equipped with: the electronic switching circuit that constitutes by diode, one-way SCR, triode, electric capacity, resistor assembly; The power supply circuit that constitutes by diode, filter capacitor, voltage stabilizing didoe, current transformer; The operation current foldback circuit that constitutes by integrated package LM324, operation overcurrent indication light-emitting diode, operation overcurrent regulator potentiometer, current transformer, diode, capacitance resistance assembly; By integrated package LM324, startup overcurrent indication light-emitting diode, start the startup current foldback circuit of overcurrent regulator potentiometer, resistance formation; The open-phase protection circuit that constitutes by integrated package LM324, current transformer, diode, triode, phase failure light emitting diode lamp, capacitance resistance assembly; By integrated package LM324, start overtime indication light-emitting diode, start overtime regulator potentiometer, the overtime protective circuit of startup that triode, diode, electric capacity, resistor assembly constitute;

The alternating current that current transformer in a, the power supply circuit induces obtains 7.5V stable DC electricity for the protective circuit electricity consumption after diode rectification, voltage-stabiliser tube voltage stabilizing, electric capacity filter,

B, startup current foldback circuit adopt integrated package (LM324) to make voltage comparator, and regulate the 5th pin current potential of IC1 by starting overcurrent regulator potentiometer (W2).