CN212301816U - Electric leakage detection circuit - Google Patents
Electric leakage detection circuit Download PDFInfo
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- CN212301816U CN212301816U CN202020386658.1U CN202020386658U CN212301816U CN 212301816 U CN212301816 U CN 212301816U CN 202020386658 U CN202020386658 U CN 202020386658U CN 212301816 U CN212301816 U CN 212301816U
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Abstract
The application provides a leakage detection circuit, includes: the device comprises a mutual inductance module, an operational amplifier module, a filtering module, a clamping protection module and a fault detection module; the mutual inductance module is used for sensing a leakage signal of a line to be detected; the clamping protection module is connected with the mutual inductance module to play a role in clamping protection of voltage signals; the input end of the operational amplifier module is connected with the mutual inductance module and is used for amplifying the detected leakage signal; the filtering module is connected with the output end of the operational amplifier module and is used for filtering the amplified leakage signal, and the output end of the filtering module is connected with the input end of a second analog-to-digital converter ADC 2; the fault detection module is connected with the mutual inductance module and used for detecting the working state of the mutual inductance module; the application provides a whether electric leakage detection circuitry can accurately judge circuit, device that awaits measuring electric leakage, whether mutual inductance module is trouble, has reduced troubleshooting time.
Description
Technical Field
The present disclosure relates generally to the field of leakage detection, and more particularly to a leakage detection circuit.
Background
The leakage detection circuit can effectively detect whether a line or a device to be detected has a leakage phenomenon, however, in the prior art, the leakage detection circuit needs to be matched with a leakage transformer to complete leakage detection; when the leakage transformer is damaged or connected in a virtual mode, the leakage detection circuit cannot complete the detection function; therefore, the phenomenon that the leakage value detected by the leakage detection circuit is zero due to the leakage of the line to be detected and the damage or virtual connection of the leakage transformer exists, and great potential safety hazards are brought.
Disclosure of Invention
In view of the above-mentioned drawbacks and deficiencies of the prior art, it is desirable to provide a leakage detection circuit with a fault detection function.
In order to solve the above problems, the utility model provides a leakage detection circuit, which comprises an mutual inductance module, an operational amplifier module, a filter module, a clamp protection module and a fault detection module;
the mutual inductance module is used for sensing a leakage signal of a line to be detected;
the clamping protection module is connected with the mutual inductance module to play a role in clamping protection of voltage signals;
the input end of the operational amplifier module is connected with the mutual inductance module and is used for amplifying the detected leakage signal;
the filtering module is connected with the output end of the operational amplifier module and is used for filtering the amplified leakage signal, and the output end of the filtering module is connected with the input end of a second analog-to-digital converter ADC 2;
the fault detection module is connected with the mutual inductance module and used for detecting the working state of the mutual inductance module.
According to the technical scheme provided by the embodiment of the application, the mutual inductance module comprises: the leakage current transformer comprises a first resistor R74, a leakage current transformer connected in parallel with two ends of the resistor R74, a leakage current transformer input pin L + and a leakage current transformer output pin L-; the mutual inductance module is used for being connected with a line to be tested through a mutual inductor input pin L + and a mutual inductor output pin L-and inducing a leakage signal through a leakage mutual inductor.
According to the technical scheme provided by the embodiment of the application, the clamping protection module comprises: a first clamping diode D1 and a second clamping diode D2; the first clamping diode D1 is connected in parallel with the second clamping diode D2 in an inverse manner and then connected in parallel with two ends of the first resistor R74.
According to the technical scheme provided by the embodiment of the application, the fault detection module comprises: the transistor Q3, the second resistor R71 and the third resistor R73; the emitter of the triode Q3 is connected with the mutual inductance module; the base electrode of the triode Q3 is connected with one end of the third resistor R73, and the other end of the third resistor R73 is connected with the input end of the first analog-to-digital converter ADC 1; the collector of the triode Q3 is connected with one end of the second resistor R71, and the other end of the second resistor R71 is connected with a 3.3V reference voltage.
According to the technical scheme provided by the embodiment of the application, the triode Q3 is an NPN type triode.
According to the technical scheme provided by the embodiment of the application, the operational amplifier module is a same-direction proportional operational amplifier circuit.
According to the technical scheme provided by the embodiment of the application, the filtering module comprises: a fourth resistor R72 and a first capacitor C41; one end of the fourth resistor is connected to the output end of the operational amplifier module, and the other end of the fourth resistor R72 is connected to one end of the first capacitor C41 and the input end of the second analog-to-digital converter ADC 2; the other end of the first capacitor C41 is grounded.
The utility model has the advantages that: the utility model provides a leakage detection circuit, which comprises a mutual inductance module, an operational amplifier module, a filtering module, a clamping protection module and a fault detection module; the mutual inductance module is used for sensing a leakage signal of a line to be detected; the clamping protection module is connected with the mutual inductance module to play a role in clamping protection of voltage signals; the input end of the operational amplifier module is connected with the mutual inductance module and is used for amplifying the detected leakage signal; the filtering module is connected with the output end of the operational amplifier module and is used for filtering the amplified leakage signal, and the output end of the filtering module is connected with the input end of a second analog-to-digital converter ADC 2; when the line or the device to be tested has electric leakage, the mutual inductance module induces the electric leakage signal of the line to be tested, amplifies the electric leakage signal through the operational amplifier module, then filters the electric leakage signal through the filtering module, and finally transmits the electric leakage signal to the second analog-to-digital converter ADC2 and outputs the electric leakage value; meanwhile, the fault detection module is connected with the mutual inductance module and used for detecting whether the mutual inductance module works normally or not. When the output leakage value of the second analog-to-digital converter ADC2 is 0 and the fault detection module detects that the mutual inductance module works normally, it can be determined that the line or device to be detected has no leakage phenomenon. The utility model relates to a whether electric leakage detection circuit can accurately judge circuit, the device that awaits measuring electric leakage in the field application of reality, whether mutual inductance module is trouble, has also reduced troubleshooting time simultaneously.
Drawings
Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:
fig. 1 is a circuit diagram of a leakage detection circuit provided in the present application
FIG. 2 is a schematic diagram of the leakage detection circuit shown in FIG. 1
Detailed Description
The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.
Example 1
Referring to fig. 1, a leakage detection circuit provided in this embodiment includes a mutual inductance module, an operational amplifier module, a filtering module, a clamp protection module, and a fault detection module;
the mutual inductance module is used for sensing a leakage signal of a line to be detected;
the clamping protection module is connected with the mutual inductance module to play a role in clamping protection of voltage signals;
the input end of the operational amplifier module is connected with the mutual inductance module and is used for amplifying the detected leakage signal;
the filtering module is connected with the output end of the operational amplifier module and is used for filtering the amplified leakage signal, and the output end of the filtering module is connected with the input end of a second analog-to-digital converter ADC 2;
the fault detection module is connected with the mutual inductance module and used for detecting the working state of the mutual inductance module.
As shown in fig. 2, when a line or a device to be detected has electric leakage, the mutual inductance module induces an electric leakage signal of the line to be detected, amplifies the electric leakage signal through the operational amplifier module, filters the electric leakage signal through the filtering module, and finally transmits the electric leakage signal to the second analog-to-digital converter ADC2 to output an electric leakage value; meanwhile, the fault detection module is connected with the mutual inductance module and used for detecting whether the mutual inductance module works normally or not. When the output leakage value of the second analog-to-digital converter ADC2 is 0 and the fault detection module detects that the mutual inductance module works normally, it can be determined that the line or device to be detected has no leakage phenomenon. The utility model relates to a whether electric leakage detection circuit can accurately judge circuit, the device that awaits measuring electric leakage in the field application of reality, whether mutual inductance module is trouble, has also reduced troubleshooting time simultaneously.
Wherein, in a preferred embodiment of the mutual inductance module, the mutual inductance module comprises: the leakage current transformer comprises a first resistor R74, a leakage current transformer connected in parallel with two ends of the resistor R74, a leakage current transformer input pin L + and a leakage current transformer output pin L-; the mutual inductance module is used for being connected with a line to be tested through a mutual inductor input pin L + and a mutual inductor output pin L-and inducing a leakage signal through a leakage mutual inductor.
When the device is applied on site, a line or a device to be tested needs to be connected to the input pin L + of the leakage transformer and the output pin L-; when the circuit or device to be tested has an electric leakage phenomenon, voltage drop is generated at two ends of the resistor R74, the voltage drop is amplified by the operational amplifier module and filtered by the filtering module, and the voltage drop is finally input into the second analog-to-digital converter ADC2 to output a leakage value.
Wherein, in a preferred embodiment of the clamp protection module, the clamp protection module comprises: a first clamping diode D1 and a second clamping diode D2; the first clamping diode D1 is connected in parallel with the second clamping diode D2 in an inverse manner and then connected in parallel with two ends of the first resistor R74.
When the leakage transformer is short-circuited or a large current is generated in a circuit operated by mistake, the voltage drop across the resistor R74 is overlarge. The clamping protection module can enable the voltage at the two ends of the R74 to be in a certain voltage range, and prevent the resistor R74 or other devices from being damaged due to overlarge voltage drop.
In a preferred embodiment of the fault detection module, the fault detection module includes: the transistor Q3, the second resistor R71 and the third resistor R73; an emitting electrode of the triode Q3 is connected with a leakage transformer input pin L + of the mutual inductance module; the base electrode of the triode Q3 is connected with one end of the third resistor R73, and the other end of the third resistor R73 is connected with the input end of the first analog-to-digital converter ADC 1; the collector of the triode Q3 is connected with one end of the second resistor R71, and the other end of the second resistor R71 is connected with a 3.3V reference voltage.
The fault detection module may be configured to detect whether the mutual inductance module is operating normally, for example, when the transistor Q3 is turned on: if the leakage value detected by the ADC2 is larger than 3993MA, the leakage transformer in the mutual inductance module is disconnected; if the leakage value detected by the ADC1 is smaller than 2720MA, the leakage transformer in the mutual inductance module is short-circuited; if the leakage value detected by the ADC1 is between 2721MA and 3992MA, the leakage transformer in the mutual inductance module is normal. When the circuit simultaneously meets the condition that the detected leakage value of the ADC2 is 0 and the detected leakage value of the ADC1 is between 2721MA and 3992MA, the circuit, the device or the leakage transformer to be detected can be determined to work normally without leakage.
In a preferred embodiment of the fault detection module, the transistor Q3 is an NPN transistor. Preferably, the triode Q3 may be a 9013NPN type triode with relatively high power
In the preferred embodiment of the operational amplifier module, the operational amplifier module is a same-direction proportional operational amplifier circuit.
Preferably, the operational amplifier module may adopt a TCL2272IDR operational amplifier with high cost performance and high performance.
Wherein, in a preferred embodiment of the filtering module, the filtering module comprises: a fourth resistor R72 and a first capacitor C41; one end of the fourth resistor is connected to the output end of the operational amplifier module, and the other end of the fourth resistor R72 is connected to one end of the first capacitor C41 and the input end of the second analog-to-digital converter ADC 2; the other end of the first capacitor C41 is grounded. The amplified leakage signal is filtered by the filtering module, so that a reliable leakage amplified signal can be output, and a leakage value is output through the second analog-to-digital converter ADC 2.
The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention as referred to in the present application is not limited to the embodiments with a specific combination of the above-mentioned features, but also covers other embodiments with any combination of the above-mentioned features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.
Claims (7)
1. An electric leakage detection circuit characterized in that: the device comprises a mutual inductance module, an operational amplifier module, a filtering module, a clamping protection module and a fault detection module;
the mutual inductance module is used for sensing a leakage signal of a line to be detected;
the clamping protection module is connected with the mutual inductance module to play a role in clamping protection of voltage signals;
the input end of the operational amplifier module is connected with the mutual inductance module and is used for amplifying the detected leakage signal;
the filtering module is connected with the output end of the operational amplifier module and is used for filtering the amplified leakage signal, and the output end of the filtering module is connected with the input end of a second analog-to-digital converter ADC 2;
the fault detection module is connected with the mutual inductance module and used for detecting the working state of the mutual inductance module.
2. The electrical leakage detection circuit of claim 1, wherein the mutual inductance module comprises: the leakage current transformer comprises a first resistor R74, a leakage current transformer connected in parallel with two ends of the resistor R74, a leakage current transformer input pin L + and a leakage current transformer output pin L-; the mutual inductance module is used for being connected with a line to be tested through a mutual inductor input pin L + and a mutual inductor output pin L-and inducing a leakage signal through a leakage mutual inductor.
3. The leakage detection circuit of claim 2, wherein the clamp protection module comprises: a first clamping diode D1 and a second clamping diode D2; the first clamping diode D1 is connected in parallel with the second clamping diode D2 in an inverse manner and then connected in parallel with two ends of the first resistor R74.
4. The electrical leakage detection circuit of claim 1, wherein the fault detection module comprises: the transistor Q3, the second resistor R71 and the third resistor R73; the emitter of the triode Q3 is connected with the mutual inductance module; the base electrode of the triode Q3 is connected with one end of the third resistor R73, and the other end of the third resistor R73 is connected with the input end of the first analog-to-digital converter ADC 1; the collector of the triode Q3 is connected with one end of the second resistor R71, and the other end of the second resistor R71 is connected with a 3.3V reference voltage.
5. The leakage detection circuit of claim 4, wherein the transistor Q3 is an NPN transistor.
6. The leakage detection circuit of claim 1, wherein the operational amplifier module is a same-direction proportional operational amplifier circuit.
7. The electrical leakage detection circuit of claim 1, wherein the filtering module comprises: a fourth resistor R72 and a first capacitor C41; one end of the fourth resistor is connected to the output end of the operational amplifier module, and the other end of the fourth resistor R72 is connected to one end of the first capacitor C41 and the input end of the second analog-to-digital converter ADC 2; the other end of the first capacitor C41 is grounded.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020386658.1U CN212301816U (en) | 2020-03-24 | 2020-03-24 | Electric leakage detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020386658.1U CN212301816U (en) | 2020-03-24 | 2020-03-24 | Electric leakage detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212301816U true CN212301816U (en) | 2021-01-05 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020386658.1U Active CN212301816U (en) | 2020-03-24 | 2020-03-24 | Electric leakage detection circuit |
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|---|---|
| CN (1) | CN212301816U (en) |
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- 2020-03-24 CN CN202020386658.1U patent/CN212301816U/en active Active
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