CN202260378U - Leakage protector - Google Patents

Leakage protector Download PDF

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Publication number
CN202260378U
CN202260378U CN201120344065XU CN201120344065U CN202260378U CN 202260378 U CN202260378 U CN 202260378U CN 201120344065X U CN201120344065X U CN 201120344065XU CN 201120344065 U CN201120344065 U CN 201120344065U CN 202260378 U CN202260378 U CN 202260378U
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CN
China
Prior art keywords
output
voltage comparator
relay
contact
connects
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Application number
CN201120344065XU
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Chinese (zh)
Inventor
吴茂义
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吴茂义
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Priority to CN201120344065XU priority Critical patent/CN202260378U/en
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Publication of CN202260378U publication Critical patent/CN202260378U/en

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Abstract

The utility model discloses a leakage protector. A first current transformer is sleeved on an output end live wire and connected with a non-inverting input end of a first voltage comparator, an inverting input end of the first voltage comparator is connected with the ground after being connected with a first resistor and connected with a voltage reduction rectifier circuit through a second resistor, the first voltage comparator is output to a base electrode of a first switching triode, a collector electrode of the first switching triode is connected to the voltage reduction rectifier circuit after being in series connection with a sixth resistor, and an emitting electrode of the first switching triode is connected to a non-inverting input end of a second voltage comparator and connected with a second contact of a first relay through a voltage splitting resistor. A first contact of the first relay is connected with the voltage reduction rectifier circuit through a third resistor, an inverting input end of the second voltage comparator is connected with the ground through a fourth resistor and connected with the voltage reduction rectifier circuit through a fifth resistor, the second voltage comparator is output to a base electrode of a second switching triode, a collector electrode of the second switching triode is connected with a coil negative electrode of the first relay, and a coil positive electrode is connected with the voltage reduction rectifier circuit. When a load is disconnected, the leakage protector can cut off power supply automatically, not only saves energy resources, but also improves safety.

Description

Earth leakage protective device

Technical field

The utility model relates to circuit protection device, is specifically related to earth leakage protective device.

Background technology

In the electrical appliance use, if open circuit fault, then also keeping certain voltage on power supply and the circuit that electrical appliance links to each other, cause easily getting an electric shock; When electrical appliance is not worked, also there is certain leakage current on the circuit all the time, this a part of electric energy is being wasted virtually; Along with the equipment increase of service time, ageing of insulation and the effect of factors etc. of making moist, leakage current can increase gradually.

The operation principle of existing earth leakage protective device is at first to detect whether electric leakage is arranged, if there is electric leakage to implement protection again, is a kind of protector of passive-type.China utility model patent CN2652004 discloses a kind of automatic outage earth leakage protective device, and its input main line passes current transformer after through the control circuit relay contact and links to each other with output.Automatically the outage earth leakage protective device can shutdown occur at electrical equipment, open circuit or circuit when leak current fault occurring, can cut off the power supply automatically, makes that voltage is zero on the circuit of power supply to electrical equipment; When electrical equipment is started shooting or after leak current fault gets rid of again, the power supply automatic recovery of power supply.But this earth leakage protective device can not solve electrical appliance when not working, and has the problem of certain leakage current on the circuit all the time.

The utility model content

The utility model technical problem to be solved is to solve when electrical appliance is not worked, and has certain leakage current on the circuit all the time, and the problem that does not possess disconnected zero active protection.

In order to solve the problems of the technologies described above; The technical scheme that the utility model adopted provides a kind of earth leakage protective device; Comprise input, output, step-down rectifying circuit and load control circuit; Said load control circuit comprises first relay, first current transformer, first voltage comparator, first switch triode and second voltage comparator, second switch triode; Said first relay is the conversion hysteria relay, and said input is connected with said output through the contact of said first relay, and the said first current transformer ring set is connected on the live wire of said output and with the in-phase input end of first voltage comparator; Ground connection behind the inverting input of first voltage comparator connection first resistance; The inverting input of first voltage comparator also connects the output that is connected to step-down rectifying circuit behind second resistance, and the output of first voltage comparator is connected to the base stage of first switch triode, and the collector electrode of first switch triode is connected and is connected to the output of step-down rectifying circuit behind the 6th resistance; The emitter of first switch triode is connected to the in-phase input end of second voltage comparator; The in-phase input end of second voltage comparator connects behind the divider resistance and the corresponding normally-closed contact in second contact simultaneously, and the other end ground connection of divider resistance and is connected with the output of step-down rectifying circuit after the corresponding normally-closed contact in first contact is connected the 3rd resistance; The inverting input of second voltage comparator is through the 4th grounding through resistance; Simultaneously, the inverting input of second voltage comparator also is connected to the output of step-down rectifying circuit through the 5th resistance, and the output of second voltage comparator connects the base stage of second switch triode; The second switch transistor collector connects the coil negative pole of first relay, and the coil electrode of first relay connects the output of step-down rectifying circuit.

In such scheme, also comprise leakage protection circuit, said leakage protection circuit comprises second current transformer, tertiary voltage comparator and second relay; Second relay has the 3rd, the 4 two contact; Wherein the 3rd contact is a normally opened contact, and the 4th contact is a normally-closed contact, and the 3rd contact is connected between the second relay coil negative pole and the ground wire; The 4th contact is serially connected between rectification circuit output end and the load control circuit; The second current transformer ring set is connected on output and with the in-phase input end of tertiary voltage comparator, and the inverting input of tertiary voltage comparator connects ground connection behind the 7th resistance, simultaneously; The inverting input of tertiary voltage comparator also connects the output that is connected to step-down rectifying circuit behind the 8th resistance; The output of tertiary voltage comparator connects the base stage of the 3rd switch triode, and the collector electrode of the 3rd switch triode connects the coil negative pole of second relay, and the coil electrode of second relay is connected to the output of step-down rectifying circuit.

In such scheme; Be provided with the leak(age) test button between the live wire of output, the zero line; One end of leak(age) test button connects the zero line of output, and the other end connects the live wire of output, and second current transformer is arranged between above-mentioned two tie points of leak(age) test button.

In such scheme, the circuit between the coil electrode of second relay and the step-down rectifying circuit output is provided with SR.

In such scheme, be provided with indicator light between the live wire of output, the zero line.

The utility model is provided with load control circuit, according to the access or the disconnection of load; Voltage comparator output high level or low level, control relay is switched on or switched off input, output, thereby has realized when load is broken off; Can stop automatically powering to the load; Circuit and load are all not charged like this, have both saved the energy, have improved fail safe again.

Compare with existing earth leakage protective device, existing earth leakage protective device is when operation, if opening circuit appears in the end of incoming cables zero line; Live wire still has voltage output; Even get an electric shock in this case, can not realize earth leakage protective, and the utility model can be realized disconnected zero protection; No matter be or the zero line break situation appears in leading-out terminal, the output of all can cutting off the electricity supply in the end of incoming cables.

Description of drawings

Fig. 1 is the circuit diagram of the utility model;

Equivalent circuit diagram when Fig. 2 is connected to load live wire, zero line output for the utility model load;

Equivalent circuit diagram when Fig. 3 is the utility model load operate as normal.

Embodiment

The earth leakage protective device that the utility model provides is except having creepage protection function; When load is broken off, can stop automatically powering to the load, circuit and load are all not charged like this; Both saved the energy; Improved fail safe again, and can realize no matter being or existing zero line break situation occurring bringing out, the output of all can cutting off the electricity supply in the end of incoming cables.The core of present technique scheme is, is provided with load control circuit in the utility model.

Below in conjunction with accompanying drawing the utility model is made detailed explanation.

As shown in Figure 1, the earth leakage protective device that the utility model provides has and is used to connect power firestreak, the zero line input 11,12 of importing power supply and the load live wire that is used to connect load, zero line output 21,22.

This earth leakage protective device is provided with step-down rectifying circuit, load control circuit and leakage protection circuit, starts this earth leakage protective device through the hand switch SH that is arranged between power firestreak input and the step-down rectifying circuit.

Step-down rectifying circuit will be load control circuit and leakage protection circuit power supply after the 220V voltage step-down rectification of power firestreak, 11,12 inputs of zero line input.

Load control circuit comprises first relay K 1, the first current transformer TA1, first voltage comparator ic 1, the first switch triode VT1 and second voltage comparator ic 3, second switch triode VT3.

First relay K 1 has first, second contact K11, K12; First, second contact K11, K12 are transfer contact (Z type), and the closure that power supply is fiery, zero line input 11,12 passes through first, second contact K11 and K12 respectively is communicated with load live wire, zero line output 21,22 with disconnection or breaks off.

The first current transformer TA1 ring set on the load live wire and its induced current after rectification, filtering, input to the in-phase input end of first voltage comparator ic 1; The inverting input of first voltage comparator ic 1 connects first resistance R, 1 back ground connection; The inverting input of first voltage comparator ic 1 also connects the output that is connected to step-down rectifying circuit after second resistance R 2; The output of first voltage comparator ic 1 is connected to the base stage of the first switch triode VT1; The collector electrode of the first switch triode VT1 is connected and is connected to the output of step-down rectifying circuit after the 6th resistance R 6, and the emitter of the first switch triode VT1 is connected to the in-phase input end of second voltage comparator ic 3.

The in-phase input end of second voltage comparator ic 3 connects divider resistance R0 simultaneously and is connected with the corresponding normally-closed contact of the second contact K12; The other end ground connection of divider resistance R0; Be connected the 3rd resistance R 3 backs is connected with the output of step-down rectifying circuit with the corresponding normally-closed contact of the first contact K11; The inverting input of second voltage comparator ic 3 is through the 4th resistance R 4 ground connection; Simultaneously, the inverting input of second voltage comparator ic 3 also is connected to the output of step-down rectifying circuit through the 5th resistance R 5, and the output of second voltage comparator ic 3 connects the base stage of second switch triode VT3; Second switch triode VT3 collector electrode connects the coil negative pole of first relay K 1, and the coil electrode of first relay K 1 connects the output of step-down rectifying circuit.

Press hand switch SH and start this earth leakage protective device, step-down rectifying circuit is started working.When load is connected to 21,22 last times of load live wire, zero line output; This load equivalent is in a load resistance Rx; Equivalent electric circuit is as shown in Figure 2; Divide hydraulic circuit so load resistance Rx warp constitutes with first, second contact K11, the corresponding normally-closed contact of K12 and the 3rd resistance R 3 and divider resistance R0, the in-phase input end of second voltage comparator ic 3 is imported in the pressure drop that on divider resistance R0, forms.At this moment, the voltage U 2=U0 * R0/ (Rx+R3+R0) of second voltage comparator ic, 3 in-phase input ends, the voltage U 1=U0 * R4/ (R5+R4) of second voltage comparator ic, 3 inverting inputs; Through setting to these resistance; Make U2>U1, therefore, second voltage comparator ic, 3 output high level make second switch triode VT3 saturation conduction; So first relay K 1; The normally opened contact of first, second contact K11, K12 is closed, and power firestreak, zero line input 11,12 are communicated with load live wire, zero line output 21,22, and load live wire, zero line output 21,22 have normal voltage output.

When power firestreak, zero line input 11,12 through load live wire, zero line output 21,22 and after load is communicated with; During the load operate as normal; The first current transformer TA1 detects in the load live wire has electric current to flow through, and this electric current is imported the in-phase input end of first voltage comparator ic 1 after rectification, filtering; And with the inverting input voltage ratio; Through set can make first voltage comparator ic 1 this moment in-phase input end voltage greater than inverting input voltage, so first voltage comparator ic, 1 output high level, the first triode VT1 saturation conduction.Referring to equivalent electric circuit as shown in Figure 3, at this moment, the 6th resistance R 6 constitutes with divider resistance R0 divides hydraulic circuit again; U2=(UO-Uces) * R0/ (R6+R0), wherein Uces is the saturation voltage drop of triode VT1, about 0.3V; Because U2>U1, therefore, second voltage comparator ic 3 keeps the high level output state; First relay K 1 all the time electric, power firestreak, zero line input 11,12 and load live wire, zero line output 21,22 are in conducting state, the load operate as normal all the time.

When load disconnection or circuit broken string occurred and comprise that broken string appears in any line among live wire or the zero line, so the output of the first current transformer TA1 no current was in-phase input end voltage=0 of first voltage comparator ic 1; Less than inverting input voltage, first voltage comparator ic, 1 output low level, the first triode VT1 ends; At this moment, the in-phase input end voltage U 2=0 of second voltage comparator ic 3 is less than inverting input voltage U 1; So second voltage comparator ic, 3 output low levels; The second triode VT3 ends, first relay K, 1 dead electricity, and first, second contact K11, K12 break off; Therefore power firestreak, zero line input 11,12 and load live wire, zero line output 21,22 break off; Load live wire, the output of zero line output 21,22 no-voltages, the line-to-ground that is connect does not all have alternating voltage, has guaranteed safe in utilization.

Leakage protection circuit comprises the second current transformer TA2, tertiary voltage comparator IC2 and second relay K 2; Second relay K 2 has the 3rd, the 4 two contact K21, K22; Wherein the 3rd contact K21 is a normally opened contact; The 4th contact K22 is a normally-closed contact, and the 3rd contact K21 is connected between second relay K, 2 coil negative poles and the ground wire, and the 4th contact is serially connected between rectification circuit output end and the load control circuit.

The second current transformer TA2 ring set is connected on live wire, zero line output 21,22 and with the in-phase input end of tertiary voltage comparator IC2; The inverting input of tertiary voltage comparator IC2 connects the 7th resistance R 7 back ground connection; Simultaneously; The inverting input of tertiary voltage comparator IC2 also connects the output that is connected to step-down rectifying circuit after the 8th resistance R 8; The output of tertiary voltage comparator IC2 connects the base stage of the 3rd switch triode VT2, and the collector electrode of the 3rd switch triode VT2 connects the coil negative pole of second relay K 2, and the coil electrode of second relay K 2 is connected to the output of step-down rectifying circuit.

After load was connected, if electric leakage, then the second current transformer TA2 detected leakage current in the circuit; This leakage current inputs to the in-phase input end of tertiary voltage comparator IC2 after rectification, filtering, the inverting input voltage of tertiary voltage comparator IC2 is U0 * R7/ (R7+R8), through setting the resistance of the 7th resistance R 7 and the 8th resistance R 8; Can make the magnitude of voltage of the in-phase input end of tertiary voltage comparator IC2 be higher than the inverting input magnitude of voltage, so tertiary voltage comparator IC2 output high level makes the 3rd switch triode VT2 saturation conduction; Second relay K 2 gets electric, and its first contact K21 is closed, at this moment; 2 self-lockings of second relay K, its second contact K22 breaks off, so first relay K, 1 dead electricity; First, second contact K11, K12 normally opened contact break off; The output of output no-voltage, load is cut off the power supply, and plays the purpose of protection.

Whether load live wire, zero line output 21, be connected with indicator light H1 between 22, being used for indication output end has alternating voltage output, and H1 was bright when alternating voltage output was arranged, and H1 does not work during no-output.

The utility model is provided with leak(age) test button AN at load live wire, zero line output; The end of leak(age) test button AN connects load zero line output; The other end connects load live wire output; The second current transformer TA2 is arranged between above-mentioned two tie points of leak(age) test button AN, and when leak(age) test button AN pressed, the second current transformer TA2 can detect leakage current.Leak(age) test button AN is used for regularly carrying out leak(age) test, to detect the reliability of creepage protection function.

The utility model; On the coil electrode of second relay K 2 and the circuit between the step-down rectifying circuit output, be provided with SR SB, press SR SB, second relay K, 2 dead electricity; Its normally opened contact K21 breaks off; Self-locking releasing, its normally-closed contact K22 is closed, and earth leakage protective device recovers operate as normal.

The effect of piezo-resistance Rv, diode D3 is to absorb the surge voltage that occurs in the circuit, the operate as normal of protection load control circuit.

The utility model is not limited to above-mentioned preferred forms, and anyone should learn the structural change of under the enlightenment of the utility model, making, every with the utlity model has identical or close technical scheme, all fall within the protection range of the utility model.

Claims (5)

1. earth leakage protective device; Comprise input, output and step-down rectifying circuit; It is characterized in that; Also comprise load control circuit, said load control circuit comprises first relay, first current transformer, first voltage comparator, first switch triode and second voltage comparator, second switch triode, and said first relay is the conversion hysteria relay; Said input is connected with said output through the contact of said first relay; The said first current transformer ring set is connected on the live wire of said output and with the in-phase input end of first voltage comparator, and the inverting input of first voltage comparator connects ground connection behind first resistance, and the inverting input of first voltage comparator also connects the output that is connected to step-down rectifying circuit behind second resistance; The output of first voltage comparator is connected to the base stage of first switch triode; The collector electrode of first switch triode is connected and is connected to the output of step-down rectifying circuit behind the 6th resistance, and the emitter of first switch triode is connected to the in-phase input end of second voltage comparator, and the in-phase input end of second voltage comparator connects behind the divider resistance and the corresponding normally-closed contact in second contact simultaneously; The other end ground connection of divider resistance; Be connected with the output of step-down rectifying circuit after the corresponding normally-closed contact in first contact is connected the 3rd resistance, the inverting input of second voltage comparator is through the 4th grounding through resistance, simultaneously; The inverting input of second voltage comparator also is connected to the output of step-down rectifying circuit through the 5th resistance; The output of second voltage comparator connects the base stage of second switch triode, and the second switch transistor collector connects the coil negative pole of first relay, and the coil electrode of first relay connects the output of step-down rectifying circuit.
2. earth leakage protective device as claimed in claim 1; It is characterized in that, also comprise leakage protection circuit, said leakage protection circuit comprises second current transformer, tertiary voltage comparator and second relay; Second relay has the 3rd, the 4 two contact; Wherein the 3rd contact is a normally opened contact, and the 4th contact is a normally-closed contact, and the 3rd contact is connected between the second relay coil negative pole and the ground wire; The 4th contact is serially connected between rectification circuit output end and the load control circuit; The second current transformer ring set is connected on output and with the in-phase input end of tertiary voltage comparator, and the inverting input of tertiary voltage comparator connects ground connection behind the 7th resistance, simultaneously; The inverting input of tertiary voltage comparator also connects the output that is connected to step-down rectifying circuit behind the 8th resistance; The output of tertiary voltage comparator connects the base stage of the 3rd switch triode, and the collector electrode of the 3rd switch triode connects the coil negative pole of second relay, and the coil electrode of second relay is connected to the output of step-down rectifying circuit.
3. earth leakage protective device as claimed in claim 2; It is characterized in that; Be provided with the leak(age) test button between the live wire of output, the zero line; One end of leak(age) test button connects the zero line of output, and the other end connects the live wire of output, and second current transformer is arranged between above-mentioned two tie points of leak(age) test button.
4. earth leakage protective device as claimed in claim 1 is characterized in that, the circuit between the coil electrode of second relay and the step-down rectifying circuit output is provided with SR.
5. earth leakage protective device as claimed in claim 1 is characterized in that, is provided with indicator light between the live wire of output, the zero line.
CN201120344065XU 2011-09-14 2011-09-14 Leakage protector CN202260378U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201120344065XU CN202260378U (en) 2011-09-14 2011-09-14 Leakage protector

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Application Number Priority Date Filing Date Title
CN201120344065XU CN202260378U (en) 2011-09-14 2011-09-14 Leakage protector

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CN202260378U true CN202260378U (en) 2012-05-30

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104466904A (en) * 2013-09-25 2015-03-25 深圳市海洋王照明工程有限公司 Protection circuit
CN104953537A (en) * 2015-07-27 2015-09-30 福一开电气有限公司 Overload protection switching device
CN105337292A (en) * 2015-12-04 2016-02-17 重庆臻远电气有限公司 Synchronous sampling circuit
CN107462804A (en) * 2017-09-26 2017-12-12 捍防(苏州)实业有限公司 A kind of Electrical Safety analytical equipment
CN107727987A (en) * 2017-09-26 2018-02-23 捍防(苏州)实业有限公司 A kind of Electrical Safety analysis method
CN109888575A (en) * 2019-03-05 2019-06-14 王佳旭 Electric socket

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104466904A (en) * 2013-09-25 2015-03-25 深圳市海洋王照明工程有限公司 Protection circuit
CN104466904B (en) * 2013-09-25 2018-11-27 深圳市海洋王照明工程有限公司 A kind of protection circuit
CN104953537A (en) * 2015-07-27 2015-09-30 福一开电气有限公司 Overload protection switching device
CN105337292A (en) * 2015-12-04 2016-02-17 重庆臻远电气有限公司 Synchronous sampling circuit
CN107462804A (en) * 2017-09-26 2017-12-12 捍防(苏州)实业有限公司 A kind of Electrical Safety analytical equipment
CN107727987A (en) * 2017-09-26 2018-02-23 捍防(苏州)实业有限公司 A kind of Electrical Safety analysis method
CN107727987B (en) * 2017-09-26 2019-11-05 捍防(苏州)实业有限公司 A kind of Electrical Safety analysis method
CN109888575A (en) * 2019-03-05 2019-06-14 王佳旭 Electric socket

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Granted publication date: 20120530

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