CN219123916U - Voltage limiting protection circuit - Google Patents
Voltage limiting protection circuit Download PDFInfo
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- CN219123916U CN219123916U CN202223250823.9U CN202223250823U CN219123916U CN 219123916 U CN219123916 U CN 219123916U CN 202223250823 U CN202223250823 U CN 202223250823U CN 219123916 U CN219123916 U CN 219123916U
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- triode
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Abstract
The utility model provides a voltage limiting protection circuit which comprises a voltage input end V1, a first capacitor C1, a voltage stabilizing diode D, an optical coupler E and a triode Q, wherein the negative electrode of the voltage stabilizing diode D is connected with the input voltage end, the positive electrode of the voltage stabilizing diode D is connected with the positive electrode of a light emitting diode in the optical coupler, the negative electrode of the light emitting diode in the optical coupler is grounded, the two ends of the first capacitor C1 are respectively connected with the positive electrode and the negative electrode of the light emitting diode in the optical coupler E, the collector electrode of the triode Q is connected with a pin of an external chip power supply and the emitter electrode of the triode Q is grounded, a resistor R2 is connected between the emitter electrode of a phototriode in the optical coupler E and the base electrode of the triode Q, and the collector electrode of the phototriode in the optical coupler E is connected with a reference voltage. The circuit of the utility model not only plays a role of protection, but also has simple structure, and further has low probability of failure, thus being suitable for popularization.
Description
Technical Field
The utility model relates to the technical field of circuit protection, in particular to a voltage limiting protection circuit.
Background
Along with the maturity of electronic technology in China, various circuit devices develop rapidly, however, the optical coupling protection circuit of the traditional technology has higher cost and more circuit components, so that the circuit is complicated, the use stability is affected to a certain extent, and the usability is limited, so that a concise protection circuit is urgently needed.
Disclosure of Invention
In view of this, embodiments of the present utility model provide a voltage limiting protection circuit.
The embodiment of the utility model provides a voltage limiting protection circuit, which comprises: the LED light source comprises a voltage input end V1, a first capacitor C1, a voltage stabilizing diode D, an optical coupler E and a triode Q, wherein the negative electrode of the voltage stabilizing diode D is connected with the voltage input end V1, the positive electrode of the voltage stabilizing diode D is connected with the positive electrode of a light emitting diode in the optical coupler, the negative electrode of the light emitting diode in the optical coupler is grounded, the two ends of the first capacitor C1 are respectively connected with the positive electrode and the negative electrode of the light emitting diode in the optical coupler E, the collector electrode of the triode Q is connected with a pin of an external chip power supply, the emitter electrode of the triode Q is grounded, a resistor R2 is connected between the emitter electrode of a phototriode in the optical coupler E and the base electrode of the triode Q, and the collector electrode of the phototriode in the optical coupler E is connected with a reference voltage.
Further, a resistor R1 is connected between the cathode of the zener diode D and the voltage input terminal V1, and one end of the first capacitor C1 connected to the anode of the light emitting diode in the optocoupler E is located between the resistor R1 and the cathode of the zener diode D.
Further, a second capacitor C2 is connected between the base electrode and the emitter electrode of the triode Q.
Further, the optocoupler also comprises a resistor R3, wherein one end of the resistor R3 is connected with an emitter of a phototriode in the optocoupler E, and the other end of the resistor is grounded.
Further, the triode Q is an NPN triode.
Further, a resistor R4 is connected between the reference voltage and the collector of the phototransistor in the optocoupler E.
The technical scheme provided by the embodiment of the utility model has the beneficial effects that: the voltage limiting protection circuit has reasonable structural design and fewer electronic components, so that the manufacturing cost can be effectively reduced, and the simple design of the circuit means that the probability of faults is reduced, thereby being suitable for popularization.
Drawings
Fig. 1 is a schematic diagram of the overall structure of a voltage limiting protection circuit according to the present utility model.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present utility model more apparent, embodiments of the present utility model will be further described with reference to the accompanying drawings.
Referring to fig. 1, an embodiment of the present utility model provides a voltage limiting protection circuit, which includes an input voltage terminal V1, a resistor R1, a zener diode D, a first capacitor C1, an optocoupler E, a resistor R2, a resistor R3, a resistor R4, a second capacitor C2, and a transistor Q.
The first end of the resistor R1 is connected with the input voltage end V1, the other end of the resistor R1 is connected with the cathode of the zener diode D, the anode of the zener diode D is connected with the anode of the light emitting diode in the optical coupler E, the cathode of the light emitting diode in the optical coupler E is grounded, one end of the first capacitor C1 is connected with a circuit between the resistor R1 and the cathode of the zener diode D, and the other end of the first capacitor C1 is connected with the cathode of the light emitting diode in the optical coupler E.
The collector of the phototriode in the optical coupler E is connected with a reference voltage Vref, and the resistor R4 is further connected between the collector of the phototriode in the optical coupler E and the reference voltage Vref.
The emitter of the phototriode in the optical coupler E is connected with the base of the triode Q, the resistor R2 is connected between the emitter of the phototriode in the optical coupler E and the base of the triode Q, the collector of the triode Q is connected with the 1 pin of the external chip power supply U, the emitter of the triode Q is grounded, and in the embodiment, the triode Q is an NPN triode.
One end of the resistor R3 is connected with the resistor R2 and the emitter of the phototriode in the optical coupler E in a circuit way, the other end of the resistor R3 is grounded, and one end of the second capacitor C2 is connected with the resistor R2 and the base of the triode Q in a circuit way, and the other end of the second capacitor C2 is grounded.
The working mode of the voltage limiting protection circuit in the embodiment is as follows: when the input voltage V1 passes through the voltage, the zener diode D is broken down and turned on, and the resistor R1, the zener diode D, and the optocoupler E form a current in a loop, so that the light emitting diode in the optocoupler E emits light to make the phototransistor in the optocoupler E turned on, and here, it should be noted that the first capacitor C1 plays a role of delaying the conduction of the phototransistor in the optocoupler E to protect a circuit; and after the phototriode in the optocoupler E is conducted, the base electrode of the triode Q generates voltage conduction, the voltage of the 1 pin of the external chip power supply U is pulled down, the chip stops working, and the whole power supply stops running, so that the voltage of V1 is reduced.
When the voltage of the V1 is reduced, the voltage stabilizing diode D is not conducted, no current is formed on the resistor R1, the voltage stabilizing diode D and the optical coupler E, so that the light emitting diode in the optical coupler E does not emit light, the phototriode in the optical coupler E is cut off, the triode Q is correspondingly cut off, the voltage of the 1 pin of the external chip power supply U is increased, the voltage is restored to normal operation, the voltage of the V1 is restored to normal operation, and the protection circuit can be played by repeating the operation.
In this document, terms such as front, rear, upper, lower, etc. are defined with respect to the positions of the components in the drawings and with respect to each other, for clarity and convenience in expressing the technical solution. It should be understood that the use of such orientation terms should not limit the scope of the protection sought herein.
The embodiments described above and features of the embodiments herein may be combined with each other without conflict.
The foregoing description of the preferred embodiments of the utility model is not intended to limit the utility model to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the utility model are intended to be included within the scope of the utility model.
Claims (6)
1. The utility model provides a voltage limiting protection circuit which characterized in that: the LED light source comprises a voltage input end V1, a first capacitor C1, a voltage stabilizing diode D, an optical coupler E and a triode Q, wherein the negative electrode of the voltage stabilizing diode D is connected with the voltage input end V1, the positive electrode of the voltage stabilizing diode D is connected with the positive electrode of a light emitting diode in the optical coupler, the negative electrode of the light emitting diode in the optical coupler is grounded, the two ends of the first capacitor C1 are respectively connected with the positive electrode and the negative electrode of the light emitting diode in the optical coupler E, the collector electrode of the triode Q is connected with a pin of an external chip power supply and the emitter electrode of the triode Q is grounded, a resistor R2 is connected between the emitter electrode of a phototriode in the optical coupler E and the base electrode of the triode Q, and the collector electrode of the phototriode in the optical coupler E is connected with a reference voltage.
2. A voltage limiting protection circuit as defined in claim 1, wherein: a resistor R1 is connected between the cathode of the zener diode D and the voltage input terminal V1, and one end of the first capacitor C1 connected with the anode of the light emitting diode in the optocoupler E is located between the resistor R1 and the cathode of the zener diode D.
3. A voltage limiting protection circuit as defined in claim 1, wherein: and a second capacitor C2 is connected between the base electrode and the emitter electrode of the triode Q.
4. A voltage limiting protection circuit as defined in claim 1, wherein: the optocoupler E further comprises a resistor R3, wherein one end of the resistor R3 is connected with an emitter of a phototriode in the optocoupler E, and the other end of the resistor R is grounded.
5. A voltage limiting protection circuit as defined in claim 1, wherein: the triode Q is an NPN triode.
6. A voltage limiting protection circuit as defined in claim 1, wherein: and a resistor R4 is connected between the reference voltage and the collector electrode of the phototriode in the optical coupler E.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223250823.9U CN219123916U (en) | 2022-11-30 | 2022-11-30 | Voltage limiting protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223250823.9U CN219123916U (en) | 2022-11-30 | 2022-11-30 | Voltage limiting protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219123916U true CN219123916U (en) | 2023-06-02 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202223250823.9U Active CN219123916U (en) | 2022-11-30 | 2022-11-30 | Voltage limiting protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219123916U (en) |
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2022
- 2022-11-30 CN CN202223250823.9U patent/CN219123916U/en active Active
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