CN216525992U - Detection circuit for MOSFET leakage current in electronic interlocking output board card - Google Patents
Detection circuit for MOSFET leakage current in electronic interlocking output board card Download PDFInfo
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- CN216525992U CN216525992U CN202123116507.8U CN202123116507U CN216525992U CN 216525992 U CN216525992 U CN 216525992U CN 202123116507 U CN202123116507 U CN 202123116507U CN 216525992 U CN216525992 U CN 216525992U
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- 238000001514 detection method Methods 0.000 title claims abstract description 20
- 230000001629 suppression Effects 0.000 claims description 10
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- 230000007547 defect Effects 0.000 description 1
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- 238000005516 engineering process Methods 0.000 description 1
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Abstract
The utility model discloses a detection circuit for MOSFET leakage current in an electronic interlocking output board card, which comprises a MOSFET, a relay, a first resistor, a second resistor, a unidirectional voltage regulator tube, an optocoupler and a microcontroller. One end of the MOSFET is connected to the positive electrode of an external direct-current power supply, and the other end of the MOSFET is connected with one end of the first resistor and one end of the relay; the other end of the relay is connected to one end of the controlled direct current load, and the other end of the controlled direct current load is connected to the negative electrode of the external direct current power supply; one end of the second resistor is connected with the other end of the first resistor; one end of the unidirectional voltage-stabilizing tube is connected with the other end of the second resistor, and the other end of the unidirectional voltage-stabilizing tube is connected with the primary side of the optocoupler; and the secondary side of the optocoupler is connected with the input end of the microcontroller. The detection circuit can effectively detect the MOSFET leakage current condition of more than or equal to 0.5mA, and ensures the driving safety of the rail vehicle.
Description
Technical Field
The utility model relates to a detection circuit for MOSFET leakage current in an electronic interlocking output board card.
Background
The digital output board card is an important device in an interlocking system in the field of rail transit control, and is required to be safely and reliably controlled and collected. The 6502 electric centralized relay interlock mode widely used in China originally realizes the safety output function, and the main circuit components are gravity relays, so that the wiring is complex and the occupied area is large.
With the development of electronic technology, the traditional 6502 electric centralized relay interlocking system is gradually replaced due to the advantages of small occupied area, easier control, higher safety and reliability and the like. The safety output board card is an output control board card of an electronic interlocking system, and a load is generally controlled to be lightened by an onboard electronic switch (MOSFET) and a relay. The main failure mode of the existing MOSFET is leakage current, and when the leakage current is larger than a certain value, the MOSFET is disconnected, so that the operation of turning off the output cannot be ensured. In order to prevent the load from being driven by mistake due to the leakage, it is necessary to perform effective leakage detection on the used MOSFET in real time. The existing MOSFET leakage current detection generally needs to be used with a controlled load, an output circuit cannot be absolutely isolated from the load, and partial leakage current flows to the load in the detection process.
SUMMERY OF THE UTILITY MODEL
The utility model aims to overcome the defects of the prior art and provide a detection circuit for MOSFET leakage current in an electronic interlocking output board card, which can effectively detect the MOSFET leakage current condition of more than or equal to 0.5mA, so that the circuit is guided to a safety side before the MOSFET leakage current is damaged, the output board card is early warned and replaced in advance, and the driving safety of a railway vehicle is ensured.
The purpose of the utility model is realized as follows: a detection circuit for MOSFET leakage current in an electronic interlocking output board card comprises an MOSFET, a relay, a first resistor, a second resistor, a unidirectional voltage regulator tube, an optocoupler and a microcontroller; wherein,
one end of the MOSFET is connected to the positive electrode of an external direct-current power supply, and the other end of the MOSFET is connected with one end of the first resistor and one end of the relay;
the other end of the relay is connected to one end of the controlled direct-current load, and the other end of the controlled direct-current load is connected to the negative electrode of the external direct-current power supply;
one end of the second resistor is connected with the other end of the first resistor;
one end of the unidirectional voltage-stabilizing tube is connected with the other end of the second resistor, and the other end of the unidirectional voltage-stabilizing tube is connected with the primary side of the optocoupler;
and the secondary side of the optocoupler is connected with the input end of the microcontroller.
The detection circuit for the leakage current of the MOSFET in the electronic interlock output board card further includes a transient suppression diode, one end of the transient suppression diode is connected to the connection end of the first resistor and the second resistor, and the other end of the transient suppression diode is connected to the negative electrode of the external dc power supply.
The detection circuit for MOSFET leakage current in the electronic interlocking output board card has the following characteristics: the detection circuit is formed in the electronic interlocking output board card, a load is not needed, the circuit is simple, the area is small, the cost is low, and the real-time performance is improved by directly processing digital signals through control. The leakage current signal not greater than 0.5mA can be reliably collected through testing, so that the leakage current of the MOSFET leads the circuit to the safety side before generating damage, the output board card is early warned and replaced in advance, the driving safety of the rail vehicle is ensured, the probability that the controlled load is driven by mistake is greatly reduced, the safety of an electronic interlocking system is improved, and the economic value is higher.
Drawings
Fig. 1 is a schematic diagram of a MOSFET leakage detection circuit in an electronic interlock output board of the present invention.
Detailed Description
The utility model will be further explained with reference to the drawings.
Referring to fig. 1, the detection circuit for MOSFET leakage in the electronic interlock output board of the present invention includes a MOSFET K1, a relay K2, a first resistor R1, a second resistor R2, a unidirectional voltage regulator tube Z1, an optocoupler U2, a microcontroller U3, and a transient suppression diode U1; wherein,
the MOSFET K1 and the relay K2 both belong to elements in an electronic interlocking output board card, and the MOSFET K1 is a detected object; the MOSFET K1 is used for controlling the on and off of the output board.
The source electrode of the MOSFET K1 is connected to the positive electrode P of an external direct current power supply, and the drain electrode of the MOSFET K1 is connected with one end of the first resistor R1 and one end of the relay K2;
the other end of the relay K2 is connected to one end of the controlled direct current load DCload, and the other end of the controlled direct current load DCload is connected to the negative pole N of the external direct current power supply;
one end of the second resistor R2 is connected with the other end of the first resistor R1; the first resistor R1 and the second resistor R2 are used for sensing leakage current;
a unidirectional voltage regulator tube Z1 is used for improving the detection threshold, one end of the unidirectional voltage regulator tube Z1 is connected with the other end of the second resistor R2, and the other end of the unidirectional voltage regulator tube Z1 is connected with the primary side of the optocoupler U2;
the optical coupler U2 is used for electric isolation, and the secondary side of the optical coupler U2 is connected with the input end of the microcontroller U3; the microcontroller U3 is used for judging the leakage current condition of the MOSFET K1;
the transient suppression diode U1 is used for protecting a rear-stage circuit from overvoltage damage; one end of the transient suppression diode U1 is connected to the connection end of the first resistor R1 and the second resistor R2, and the other end of the transient suppression diode U1 is connected to the negative pole N of the external direct current power supply.
The MOSFET leakage current detection circuit directly detects the leakage current state of the MOSFET in the output board card; when the MOSFET K1 generates leakage current larger than or equal to 0.5mA, the unidirectional voltage regulator tube Z1 and the optocoupler U2 are reliably conducted, the optocoupler U2 pulls down a signal output to the microcontroller U3, and the microcontroller U3 judges the leakage current condition of the MOSFET K1 according to a captured input signal from the secondary side of the optocoupler U2; when the MOSFET K1 has leakage current larger than or equal to 0.5mA, the microcontroller U3 can receive a low level signal output by the optocoupler U2, and when the MOSFET K1 does not have leakage current larger than or equal to 0.5mA, the microcontroller U3 receives a high level signal output by the optocoupler U2.
The above embodiments are provided only for illustrating the present invention and not for limiting the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and therefore all equivalent technical solutions should also fall within the scope of the present invention, and should be defined by the claims.
Claims (2)
1. A detection circuit for MOSFET leakage current in an electronic interlocking output board card is characterized in that the detection circuit comprises an MOSFET, a relay, a first resistor, a second resistor, a unidirectional voltage regulator tube, an optical coupler and a microcontroller;
one end of the MOSFET is connected to the positive electrode of an external direct-current power supply, and the other end of the MOSFET is connected with one end of the first resistor and one end of the relay;
the other end of the relay is connected to one end of the controlled direct-current load, and the other end of the controlled direct-current load is connected to the negative electrode of the external direct-current power supply;
one end of the second resistor is connected with the other end of the first resistor;
one end of the unidirectional voltage-stabilizing tube is connected with the other end of the second resistor, and the other end of the unidirectional voltage-stabilizing tube is connected with the primary side of the optocoupler;
and the secondary side of the optocoupler is connected with the input end of the microcontroller.
2. The detection circuit for the leakage current of the MOSFET in the electronic interlock output board of claim 1, further comprising a transient suppression diode, wherein one end of the transient suppression diode is connected to the connection end of the first resistor and the second resistor, and the other end of the transient suppression diode is connected to the negative electrode of the external dc power supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123116507.8U CN216525992U (en) | 2021-12-08 | 2021-12-08 | Detection circuit for MOSFET leakage current in electronic interlocking output board card |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123116507.8U CN216525992U (en) | 2021-12-08 | 2021-12-08 | Detection circuit for MOSFET leakage current in electronic interlocking output board card |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216525992U true CN216525992U (en) | 2022-05-13 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202123116507.8U Active CN216525992U (en) | 2021-12-08 | 2021-12-08 | Detection circuit for MOSFET leakage current in electronic interlocking output board card |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216525992U (en) |
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2021
- 2021-12-08 CN CN202123116507.8U patent/CN216525992U/en active Active
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