CN211151512U - Leakage protection circuit - Google Patents
Leakage protection circuit Download PDFInfo
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- CN211151512U CN211151512U CN201921973595.3U CN201921973595U CN211151512U CN 211151512 U CN211151512 U CN 211151512U CN 201921973595 U CN201921973595 U CN 201921973595U CN 211151512 U CN211151512 U CN 211151512U
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Abstract
The utility model provides an electric leakage protection circuit, electric leakage protection circuit is applied to in one or N parallelly connected lighting circuit respectively, electric leakage protection circuit includes benchmark production circuit and electric leakage detection circuit, and benchmark production circuit produces reference voltage, and reference voltage is greater than first threshold and is less than the second threshold; when the input voltage detection signal is reduced to the reference voltage, the leakage detection circuit detects whether the load input end leaks electricity; if the load input end leaks electricity, the load switch is controlled to be switched off or the load is controlled not to be enabled; if the load input end does not leak electricity, controlling the load switch to be conducted or controlling the load to be enabled; n reference voltages generated by the N leakage protection circuits are distributed between the first threshold value and the second threshold value. The utility model discloses can avoid many lamps to detect the electric leakage simultaneously, improve the parallelly connected quantity of many lamps.
Description
Technical Field
The utility model relates to a power electronics field, in particular to earth leakage protection circuit.
Background
In the prior art, as for a leakage detection circuit with multiple parallel lamps, the working waveform diagram is shown in fig. 1, when the input voltage reaches a fixed threshold, leakage detection is performed to obtain a detection current, and when the detection current I is detectedDIs less thanAnd when the reference signal is used, the leakage of the load input end is indicated, and then the leakage protection is carried out. However, when multiple lamps are connected in parallel, when leakage detection is performed simultaneously on the multiple lamps, the leakage detection result is likely to be erroneous due to the influence of line impedance, ac power supply impedance, and the like, and normal detection cannot be completed.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a can improve the electric leakage detection circuit of the parallelly connected quantity of many lamps for the problem that the electric leakage detection result easily makes mistakes when the many lamps that solve prior art existence are parallelly connected.
In order to achieve the above object, the utility model provides an earth leakage protection circuit, earth leakage protection circuit is applied to respectively in a N parallelly connected lighting circuit, earth leakage protection circuit includes:
the reference generating circuit generates a reference voltage, and the reference voltage is greater than a first threshold and less than a second threshold;
the leakage detection circuit detects whether the load input end leaks electricity or not when the input voltage drops to the reference voltage; if the load input end leaks electricity, the load switch is controlled to be switched off or the load is controlled not to be enabled; if the load input end does not leak electricity, controlling the load switch to be conducted or controlling the load to be enabled;
n reference voltages generated by the N leakage protection circuits are distributed between the first threshold value and the second threshold value.
Optionally, N reference voltages respectively generated by the N leakage protection circuits obey normal distribution, approximately obey normal distribution, or randomly distributed.
Optionally, when the leakage protection circuit is connected to the input power supply each time, a reference voltage is randomly generated each time.
Optionally, when the leakage protection circuit is connected to the input power supply each time, the reference voltages generated each time are the same.
Optionally, the reference generating circuit includes a fixed threshold generating circuit and a first threshold generating circuit, the fixed threshold generating circuit generates a fixed threshold voltage, and the first threshold generating circuit generates a first threshold voltage; and calculating the fixed threshold voltage and the first threshold voltage to obtain the reference voltage.
Optionally, the first threshold generating circuit includes one or more operational amplifier units and a first signal processing circuit, two input terminals of each operational amplifier are short-circuited, and an output signal of each operational amplifier generates the first threshold voltage through the first signal processing circuit.
Optionally, the first threshold generating circuit includes one or more unit modules and a second signal processing circuit, and output signals of the one or more unit modules generate the first threshold voltage through the second signal processing circuit; each unit module comprises two inverters, wherein the input end of one inverter is connected with the output end of the other inverter, and the output end of one inverter is the output end of each unit module.
Optionally, the leakage detection circuit includes a current detection circuit and a first comparator, a first input end of the first comparator receives an input voltage, a second input end of the first comparator receives the reference voltage, and an output signal of the first comparator controls the current detection circuit; the first end of the current detection circuit is connected with the high potential output end of the rectifying circuit or one end of the input power supply, and the second end of the current detection circuit is connected with the low potential output end of the rectifying circuit; when the input voltage detection signal is reduced to the reference voltage, the current detection circuit detects the current flowing through the first resistor to obtain a current detection signal, and if the current detection signal is lower than a first threshold value, the current detection signal represents the electric leakage of the input end of the load.
Optionally, the current detection circuit includes a first switching tube and a second comparator, a first end of the first switching tube is directly or indirectly connected to a high potential output end of the rectification circuit or one end of the input power supply, and a second end of the first switching tube is connected to a low potential output end of the rectification circuit through a first resistor; when the input voltage detection signal is reduced to the reference voltage, the first switch tube is conducted briefly, and the voltage of the second end of the first switch tube is the current detection signal; the first input end of the second comparator is connected with the second end of the first switch tube, the second end of the second comparator receives a first threshold value, and the output signal of the second comparator represents whether the input end of the load leaks electricity or not.
Compared with the prior art, the utility model has the advantages of it is following: the leakage protection circuit is respectively applied to the N lighting circuits which are connected in parallel, and generates reference voltage; when the input voltage drops to the reference voltage, detecting whether the input end of the load leaks electricity; if the load input end leaks electricity, the load switch is controlled to be switched off or the load is controlled not to be enabled; if the load input end does not leak electricity, controlling the load switch to be conducted or controlling the load to be enabled; the N leakage protection circuits respectively generate N reference voltages which are distributed between the first threshold value and the second threshold value. The utility model discloses can avoid many lamps to detect the electric leakage simultaneously, improve the parallelly connected quantity of many lamps.
Drawings
FIG. 1 is a waveform diagram illustrating the operation of a leakage detection circuit according to the prior art;
FIG. 2 is a waveform diagram of the leakage detection circuit of the present invention;
FIG. 3 is a schematic diagram of the leakage detecting circuit of the present invention;
fig. 4 is a schematic diagram of an embodiment of a first threshold generation circuit of the present invention;
fig. 5 is a schematic diagram of a second embodiment of the first threshold generation circuit of the present invention;
Detailed Description
The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention is not limited to only these embodiments. The present invention covers any alternatives, modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.
In the following description of the preferred embodiments of the present invention, specific details are set forth in order to provide a thorough understanding of the present invention, and it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.
The invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. It should be noted that the drawings are simplified and in non-precise proportion, so as to facilitate and clearly assist in explaining the embodiments of the present invention.
As shown in fig. 2, the utility model discloses electric leakage detection circuitry work oscillogram, in certain detection window of input voltage, electric leakage detection circuitry's electric leakage detection time is relatively more random among the different lighting circuit, has reduced the probability of carrying out electric leakage detection simultaneously, has promoted a plurality of lighting circuit's parallelly connected quantity.
As shown in fig. 3, the schematic diagram of the leakage detection circuit of the present invention is illustrated, which includes a reference generating circuit U00, a comparator U01, a driving circuit U03, a switch Q1, a resistor R1, a comparator U02, and a driving circuit U03. The reference generating circuit U00 comprises a fixed threshold generating circuit generating a fixed threshold voltage V1, a first threshold generating circuit generating a first threshold voltage V2; the fixed threshold voltage V1 and the first threshold voltage V2 are calculated to obtain the reference voltage Vref 1. The comparator U01 has a non-inverting input terminal receiving a reference voltage Vref1, an inverting input terminal receiving an input voltage sampling signal VCS, and an output terminal outputting a first comparison signal VC1, wherein the input voltage is an ac power supply or is obtained by rectifying the ac power supply. The first end of the switching tube Q1 is connected with the high potential end of the rectifying circuit or one end of the alternating current input, the second end of the switching tube Q2 is grounded through a resistor R1, and a first comparison signal VC1 drives the switching tube Q1 to be switched on and off through a driving circuit U03. The non-inverting input terminal of the comparator U02 is connected to the second terminal of the switch Q1, the inverting input terminal thereof receives the threshold signal Vref2, and the output terminal thereof outputs the second comparison signal VC 2. When the sampling signal VCS drops to Vref1, the first comparison signal VC1 controls the switching tube Q1 to be turned on briefly, the voltage at the second end of the switching tube Q1 is a current detection signal, when the current detection signal is smaller than the threshold signal Vref2, it indicates that the load input end is leaked, and the second comparison signal VC2 controls the load switch off M00 to be turned off or the load to be disabled.
As shown in fig. 4, a schematic diagram of an embodiment of the first threshold generation circuit of the present invention is illustrated, including a plurality of operational amplifiers, two input terminals of each operational amplifier are connected, and an output signal of each operational amplifier is obtained after being operated by an operation circuit, where the first threshold voltage V2 is obtained. The first threshold voltage V2 generated by the earth leakage protection circuit is the same each time it is powered up. That is, each different earth leakage protection circuit generates the first threshold voltage V2 unchanged after each power-up. The plurality of first threshold voltages V2 generated by the plurality of different leakage protection circuits may follow a distribution such as a normal distribution, an approximate positive distribution, or a random distribution.
As shown in fig. 5, a schematic diagram of a second embodiment of the first threshold generation circuit of the present invention is illustrated, which includes a plurality of unit modules, each unit module includes two inverters, an input terminal of one inverter is connected to an input terminal of another inverter, an output signal of one inverter is used as an output signal of the unit module, and the output signal of each unit module is operated by an operation circuit to obtain the first threshold voltage V2. Each time the earth leakage protection circuit is powered up, it randomly generates a first threshold voltage V2. That is, the first threshold voltage V2 generated each time the earth leakage protection circuit is powered on may be different. The first threshold voltages V2 generated by the plurality of different leakage protection circuits may follow a distribution, such as a normal distribution, an approximate positive distribution, or a random distribution.
Although the embodiments have been described and illustrated separately, it will be apparent to those skilled in the art that some common techniques may be substituted and integrated between the embodiments, and reference may be made to one of the embodiments not explicitly described, or to another embodiment described.
The above-described embodiments do not limit the scope of the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the above-described embodiments should be included in the protection scope of the technical solution.
Claims (9)
1. The utility model provides a leakage protection circuit, leakage protection circuit is applied to respectively in N parallelly connected lighting circuit, its characterized in that: the leakage protection circuit includes:
the reference generating circuit generates a reference voltage, and the reference voltage is greater than a first threshold and less than a second threshold;
the leakage detection circuit detects whether the input end of the load leaks electricity or not when the input voltage reaches the reference voltage; if the load input end leaks electricity, the load switch is controlled to be switched off or the load is controlled not to be enabled; if the load input end does not leak electricity, controlling the load switch to be conducted or controlling the load to be enabled;
n reference voltages generated by the N leakage protection circuits are distributed between the first threshold value and the second threshold value.
2. The earth leakage protection circuit of claim 1, wherein: the N reference voltages respectively generated by the N leakage protection circuits are distributed according to a normal distribution, approximately according to a normal distribution or randomly.
3. A leakage protection circuit according to claim 1 or 2, wherein: the leakage protection circuit randomly generates a reference voltage each time when being connected with an input power supply.
4. A leakage protection circuit according to claim 1 or 2, wherein: when the leakage protection circuit is connected with an input power supply every time, the reference voltage generated every time is the same.
5. A leakage protection circuit according to claim 1 or 2, wherein: the reference generating circuit comprises a fixed threshold generating circuit and a first threshold generating circuit, wherein the fixed threshold generating circuit generates a fixed threshold voltage, and the first threshold generating circuit generates a first threshold voltage; and calculating the fixed threshold voltage and the first threshold voltage to obtain the reference voltage.
6. The leakage protection circuit of claim 5, wherein: the first threshold generating circuit comprises one or more operational amplifier units and a first signal processing circuit, two input ends of each operational amplifier are in short circuit, and an output signal of each operational amplifier generates the first threshold voltage through the first signal processing circuit.
7. The leakage protection circuit of claim 5, wherein: the first threshold generating circuit comprises one or more unit modules and a second signal processing circuit, and output signals of the one or more unit modules generate the first threshold voltage through the second signal processing circuit; each unit module comprises two inverters, wherein the input end of one inverter is connected with the output end of the other inverter, and the output end of one inverter is the output end of each unit module.
8. The leakage protection circuit of claim 7, wherein: the leakage detection circuit comprises a current detection circuit and a first comparator, wherein a first input end of the first comparator receives an input voltage, a second input end of the first comparator receives the reference voltage, and a signal output by the first comparator controls the current detection circuit; the first end of the current detection circuit is connected with the high potential output end of the rectifying circuit or one end of the input power supply, and the second end of the current detection circuit is connected with the low potential output end of the rectifying circuit; when the input voltage is reduced to the reference voltage, the current detection circuit detects the current flowing through the first resistor to obtain a current detection signal, and if the current detection signal is lower than a first threshold value, the current detection signal represents the electric leakage of the input end of the load.
9. The earth leakage protection circuit of claim 8, wherein: the current detection circuit comprises a first switching tube and a second comparator, wherein a first end of the first switching tube is directly or indirectly connected with a high-potential output end of the rectification circuit or one end of an input power supply, and a second end of the first switching tube is connected with a low-potential output end of the rectification circuit through a first resistor; when the input voltage drops to the reference voltage, the first switch tube is conducted briefly, and the voltage of the second end of the first switch tube is the current detection signal; the first input end of the second comparator is connected with the second end of the first switch tube, the second end of the second comparator receives a first threshold value, and the output signal of the second comparator represents whether the input end of the load leaks electricity or not.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921973595.3U CN211151512U (en) | 2019-11-15 | 2019-11-15 | Leakage protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921973595.3U CN211151512U (en) | 2019-11-15 | 2019-11-15 | Leakage protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211151512U true CN211151512U (en) | 2020-07-31 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921973595.3U Active CN211151512U (en) | 2019-11-15 | 2019-11-15 | Leakage protection circuit |
Country Status (1)
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|---|---|
| CN (1) | CN211151512U (en) |
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2019
- 2019-11-15 CN CN201921973595.3U patent/CN211151512U/en active Active
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Address after: Room 901-23, 9 / F, west 4 building, Xigang development center, 298 Zhenhua Road, Sandun Town, Xihu District, Hangzhou City, Zhejiang Province, 310030 Patentee after: Jiehuate Microelectronics Co.,Ltd. Address before: Room 901-23, 9 / F, west 4 building, Xigang development center, 298 Zhenhua Road, Sandun Town, Xihu District, Hangzhou City, Zhejiang Province, 310030 Patentee before: JOULWATT TECHNOLOGY (HANGZHOU) Co.,Ltd. |
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