CN109390906B - Leakage protection circuit for household appliances - Google Patents
Leakage protection circuit for household appliances Download PDFInfo
- Publication number
- CN109390906B CN109390906B CN201710653616.2A CN201710653616A CN109390906B CN 109390906 B CN109390906 B CN 109390906B CN 201710653616 A CN201710653616 A CN 201710653616A CN 109390906 B CN109390906 B CN 109390906B
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- triode
- resistor
- current transformer
- circuit
- leakage
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- 238000001514 detection method Methods 0.000 claims abstract description 10
- 239000003990 capacitor Substances 0.000 claims description 13
- 238000012360 testing method Methods 0.000 abstract description 4
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- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 206010063385 Intellectualisation Diseases 0.000 description 1
- 208000027418 Wounds and injury Diseases 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 208000014674 injury Diseases 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
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- 238000003199 nucleic acid amplification method Methods 0.000 description 1
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Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/26—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
- H02H3/32—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors
Abstract
The invention provides a household appliance leakage protection circuit, which comprises a control circuit, a signal receiving circuit and a push-pull test circuit, wherein the control circuit controls the on and off of the control circuit, when leakage occurs, the current in a primary coil of a current transformer in the control circuit changes, so that a leakage signal is formed, a secondary coil of the current transformer receives the leakage signal and gives an alarm, the control circuit can be timely reminded to be turned off, and personal and property losses are avoided; the push-pull detection circuit is also arranged, so that the leakage detection capability of the leakage protection circuit can be tested, and a reference is provided for practical use. The invention can accurately detect the leakage signal in the use of the household appliance, improves the safety coefficient of the use of the household appliance, ensures the personal and property safety and has higher application value.
Description
Technical Field
The invention relates to the technical field of safe use of household appliances, in particular to a household appliance leakage protection circuit.
Background
With the development of technology, the integration degree of the household appliances is higher and higher, and the functions are more complete. A problem that follows is that the internal wiring of the household appliance is also becoming more and more complex. At present, household appliances with water in the market, such as a body cleaner, a washing machine and the like, have very complicated internal circuits and are more and more difficult to design scientifically and reasonably. As the service time increases, the line may leak due to: (1) After long-time use, the outer skin of the power wire of the household appliance is provided with worn-out or bare wires, and once the bare wires contact the outer shell or other metal parts, electric leakage is caused; (2) The long-term vibration friction between the lead wire in the machine and the shell causes the electric leakage caused by the contact of the ground wire sheath with the shell; (3) The lead wires and connecting wires inside the electrical appliance are exposed at the joint of the wrapped and fixed lead wires due to poor process, so that electric leakage is caused. The circuit does not have relevant circuits for carrying out proper leakage early warning, so that property loss caused by leakage can be caused, and even serious consequences such as personal injury and death can be caused.
Disclosure of Invention
In order to solve the technical problems, the invention aims to provide the leakage protection circuit for the household appliance, which can timely detect a leakage signal and send out an alarm to improve the safety coefficient of the household appliance.
In order to achieve the technical effects, the household appliance leakage protection circuit provided by the invention comprises a control circuit 1 and a signal receiving circuit 2, wherein the signal receiving circuit 2 receives a leakage signal of the control circuit 1 and sends an alarm signal, the control circuit 1 comprises a current transformer TA, a double-contact relay J1 and a piezoresistor, and an alternating current L line and an alternating current N line are respectively connected with a load through primary coils L1 and L2 of the current transformer TA and two contacts of the relay; the piezoresistor is connected in parallel between two contacts of the relay; the signal receiving circuit 2 comprises a capacitor C8, resistors R3 and R10 and diodes D8 and D9, and one end of a secondary coil L3 of the current transformer is grounded; the capacitor C8, the resistor R3, the resistor R10, the diode D8 and the diode D9 are sequentially connected in parallel with two ends of the secondary coil L3 of the current transformer, wherein the cathode of the diode D8 and the anode of the diode D9 are grounded; the cathode of the diode D9 is an electric leakage alarm signal output end.
As a further improvement of the invention:
the push-pull detection circuit 3 comprises NPN triodes Q2 and Q3 and a PNP triode Q4, wherein the base electrode of the triode Q2 is used as an input end through a resistor R27, the collector electrode of the triode Q2 is connected with a power supply voltage through a resistor R25, and the emitter electrode of the triode Q2 is grounded; the collector of the triode Q3 is connected with a power supply voltage through a resistor R26, and the emitter of the triode Q3 is connected with the emitter of the triode Q4; the collector of the triode Q4 is grounded through a resistor R22; the base electrode of the triode Q3 is connected with the collector electrode of the triode Q2 through a resistor R23; the base electrode of the triode Q4 is connected with the collector electrode of the triode Q2 through a resistor R24; an emitter of the triode Q3 is connected with the positive electrode of the electrolytic capacitor E1, and a negative electrode of the electrolytic capacitor E1 is connected with the grounding end of the current transformer secondary coil L3 through the current transformer secondary coil L4.
According to the technical scheme, the household appliance leakage protection circuit provided by the invention has the advantages that the signal receiving circuit can timely sense the leakage signal at the side of the control circuit through the current transformer and send out an alarm signal, and the current transformer can isolate alternating current, so that the safety of the circuit is improved; the push-pull detection circuit is also arranged, so that the leakage checking capability of the leakage protection circuit can be detected, and the use reliability of the leakage protection circuit can be improved.
Drawings
Fig. 1 is a circuit diagram of the present invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings:
as shown in fig. 1, the leakage protection circuit of the household appliance in the embodiment comprises a control circuit 1 and a signal receiving circuit 2, and preferably, the leakage protection circuit in the embodiment also comprises a push-pull detection circuit 3, wherein the control circuit 1 controls the connection of alternating current and a load, and the signal receiving circuit 2 receives a leakage signal in the control circuit and timely sends out an alarm signal; the push-pull test circuit 3 can test the alarm signal threshold value of the signal receiving circuit and detect the working state of the signal receiving circuit, and provides reference for the use reliability of the leakage protection circuit.
Specifically, the control circuit 1 comprises a current transformer TA, a double-contact relay J1 and a piezoresistor, wherein an alternating current L line and an alternating current N line are respectively connected with a load through primary coils L1 and L2 of the current transformer TA and two contacts of the relay; the piezoresistor is connected in parallel between two contacts of the relay, so that protection can be provided for a subsequent load; the relay can be controlled to be turned on and off by a chip output signal, and the power supply voltage is +12V.
The signal receiving circuit 2 comprises a capacitor C8, resistors R3 and R10 and diodes D8 and D9, and one end of a secondary coil L3 of the current transformer is grounded; the capacitor C8, the resistor R3, the resistor R10, the diode D8 and the diode D9 are sequentially connected in parallel with two ends of the secondary coil L3 of the current transformer, wherein the cathode of the diode D8 and the anode of the diode D9 are grounded; the cathode of the diode D9 is an electric leakage alarm signal output end. Wherein, C8, R3, R10 constitute low pass filter circuit, prevent the erroneous judgement with noise filtering, and diode D8 and D9 play the effect of protecting the chip end, prevent that the excessive high chip breakdown of instantaneous voltage. The signal receiving circuit is used for converting the primary generated leakage signal into the leakage signal at the LEAKAGECUR end through the coupling of the primary coil L3 and the secondary coil L3, so as to achieve the detection effect.
The push-pull detection circuit 3 comprises NPN triodes Q2 and Q3 and a PNP triode Q4, wherein the base electrode of the triode Q2 is used as an input end through a resistor R27, the collector electrode of the triode Q2 is connected with a power supply voltage through a resistor R25, and the emitter electrode of the triode Q2 is grounded; the collector of the triode Q3 is connected with a power supply voltage through a resistor R26, and the emitter of the triode Q3 is connected with the emitter of the triode Q4; the collector of the triode Q4 is grounded through a resistor R22; the base electrode of the triode Q3 is connected with the collector electrode of the triode Q2 through a resistor R23; the base electrode of the triode Q4 is connected with the collector electrode of the triode Q2 through a resistor R24; an emitter of the triode Q3 is connected with the positive electrode of the electrolytic capacitor E1, and a negative electrode of the electrolytic capacitor E1 is connected with the grounding end of the secondary coil L3 of the current transformer through the secondary coil L4 of the current transformer TA. The push-pull detection circuit is used for emitting a test square wave signal from a LEAKCTEST end, carrying out amplitude amplification through a push-pull circuit consisting of Q2, Q3 and Q4 and all resistors, changing the signal into a signal which is not easy to interfere, changing the signal into a weak alternating current signal through filtering of an electrolytic capacitor, simulating the leakage condition, and changing the signal into an alarm signal through coupling of a current transformer secondary coil L4 to a grounding end of a current transformer secondary coil L3, thereby detecting the leakage checking capability.
The invention can timely and accurately detect the leakage signal and give an alarm, provides a new circuit design for leakage protection, has accurate and timely detection, can be connected with a related controller in an expanded manner, and can timely disconnect the connection of a control circuit so as to realize the intellectualization of the leakage protection of the household appliance. The invention has good application value and popularization prospect.
The above examples are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solution of the present invention should fall within the scope of protection defined by the claims of the present invention without departing from the spirit of the present invention.
Claims (1)
1. A household appliance leakage protection circuit is characterized in that: the control circuit (1) comprises a current transformer TA, a double-contact relay J1 and a piezoresistor, wherein an alternating current L line and an alternating current N line are respectively connected with a load through primary coils L1 and L2 of the current transformer TA and two contacts of the relay; the piezoresistor is connected in parallel between two contacts of the relay; the signal receiving circuit (2) comprises a capacitor C8, resistors R3 and R10 and diodes D8 and D9, and one end of a secondary coil L3 of the current transformer is grounded; the capacitor C8, the resistor R3, the resistor R10, the diode D8 and the diode D9 are sequentially connected in parallel with two ends of the secondary coil L3 of the current transformer, wherein the cathode of the diode D8 and the anode of the diode D9 are grounded; the cathode of the diode D9 is a leakage alarm signal output end;
the push-pull detection circuit (3) comprises NPN triodes Q2 and Q3 and a PNP triode Q4, wherein the base electrode of the triode Q2 is an input end through a resistor R27, the collector electrode of the triode Q2 is connected with a power supply voltage through a resistor R25, and the emitter electrode of the triode Q2 is grounded; the collector of the triode Q3 is connected with a power supply voltage through a resistor R26, and the emitter of the triode Q3 is connected with the emitter of the triode Q4; the collector of the triode Q4 is grounded through a resistor R22; the base electrode of the triode Q3 is connected with the collector electrode of the triode Q2 through a resistor R23; the base electrode of the triode Q4 is connected with the collector electrode of the triode Q2 through a resistor R24; an emitter of the triode Q3 is connected with the positive electrode of the electrolytic capacitor E1, and a negative electrode of the electrolytic capacitor E1 is connected with the grounding end of the current transformer secondary coil L3 through the current transformer secondary coil L4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710653616.2A CN109390906B (en) | 2017-08-02 | 2017-08-02 | Leakage protection circuit for household appliances |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710653616.2A CN109390906B (en) | 2017-08-02 | 2017-08-02 | Leakage protection circuit for household appliances |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109390906A CN109390906A (en) | 2019-02-26 |
| CN109390906B true CN109390906B (en) | 2024-02-09 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710653616.2A Active CN109390906B (en) | 2017-08-02 | 2017-08-02 | Leakage protection circuit for household appliances |
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| Country | Link |
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| CN (1) | CN109390906B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111983505A (en) * | 2019-05-06 | 2020-11-24 | 江苏新安电器股份有限公司 | Washing machine electric leakage detection system |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101488657A (en) * | 2009-02-23 | 2009-07-22 | 深圳创维－Rgb电子有限公司 | Detection and protection apparatus for leakage |
| CN201868846U (en) * | 2010-12-07 | 2011-06-15 | 合肥荣事达三洋电器股份有限公司 | Earth-leakage protection controller |
| CN103326325A (en) * | 2013-06-05 | 2013-09-25 | 广州凯盛电子科技有限公司 | Short-circuit and low-voltage protective circuit of output of switching power source |
| CN104993451A (en) * | 2015-08-03 | 2015-10-21 | 刘圣平 | Very effective leakage protector |
| CN205489453U (en) * | 2016-01-04 | 2016-08-17 | 广州金田瑞麟净化设备制造有限公司 | Leakage protective circuit |
| CN207353822U (en) * | 2017-08-02 | 2018-05-11 | 惠而浦（中国）股份有限公司 | A kind of household electrical appliance leakage protection circuit |
-
2017
- 2017-08-02 CN CN201710653616.2A patent/CN109390906B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101488657A (en) * | 2009-02-23 | 2009-07-22 | 深圳创维－Rgb电子有限公司 | Detection and protection apparatus for leakage |
| CN201868846U (en) * | 2010-12-07 | 2011-06-15 | 合肥荣事达三洋电器股份有限公司 | Earth-leakage protection controller |
| CN103326325A (en) * | 2013-06-05 | 2013-09-25 | 广州凯盛电子科技有限公司 | Short-circuit and low-voltage protective circuit of output of switching power source |
| CN104993451A (en) * | 2015-08-03 | 2015-10-21 | 刘圣平 | Very effective leakage protector |
| CN205489453U (en) * | 2016-01-04 | 2016-08-17 | 广州金田瑞麟净化设备制造有限公司 | Leakage protective circuit |
| CN207353822U (en) * | 2017-08-02 | 2018-05-11 | 惠而浦（中国）股份有限公司 | A kind of household electrical appliance leakage protection circuit |
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| Publication number | Publication date |
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| CN109390906A (en) | 2019-02-26 |
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