CN210053210U - Overvoltage protection circuit - Google Patents
Overvoltage protection circuit Download PDFInfo
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- CN210053210U CN210053210U CN201921136172.6U CN201921136172U CN210053210U CN 210053210 U CN210053210 U CN 210053210U CN 201921136172 U CN201921136172 U CN 201921136172U CN 210053210 U CN210053210 U CN 210053210U
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- adapter
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Abstract
The utility model relates to the field of circuits, in particular to an overvoltage protection circuit, which is connected with an adapter and comprises a voltage stabilizing circuit and a power switch circuit; the power switch circuit comprises resistors R2 and R3, a triode QC5 and an MOS tube Q1, the voltage stabilizing circuit comprises a diode D1 and a resistor R1, a resistor R1 is connected with the negative electrode of the diode D1, one end of a resistor R2 is connected with the negative electrode of the resistor R1 and the negative electrode of the diode D1, the other end of the resistor R2 is connected with the b level of the triode QC5, the c level of the triode QC5 is connected with one ends of the MOS tube Q1 and the resistor R3, the other end of the resistor R3 is grounded and connected with the positive electrode of the diode D1, and the adapter is connected with the e level of the resistor R1 and the triode QC. This application, through voltage stabilizing circuit and switch circuit's cooperation, can realize overvoltage protection through simple circuit to avoid the voltage too high and burn out circuit element, reach protection circuit's effect.
Description
Technical Field
The utility model relates to a circuit field, concretely relates to overvoltage crowbar.
Background
In the electrical field, in view of some unstable factors existing in a power circuit, some circuits are designed to prevent the unstable factors from affecting the circuits, for example, an overvoltage protection circuit designed when the voltage is too large and the voltage is too serious can cause damage to components, so the overvoltage protection circuit is generally required to be designed to solve the problem of voltage overvoltage, and the traditional overvoltage protection circuit uses too many components and has a complex structure, which causes higher cost.
SUMMERY OF THE UTILITY MODEL
In order to solve the above problems, an object of the present invention is to provide an overvoltage protection circuit, which uses less components, has a simple structure and is low in cost.
The utility model aims at realizing through the following technical scheme:
the utility model provides an overvoltage protection circuit, which is connected with an adapter and comprises a voltage stabilizing circuit and a power switch circuit; the power switch circuit comprises resistors R2 and R3, a triode QC5 and an MOS tube Q1, the voltage stabilizing circuit comprises a diode D1 and a resistor R1, a resistor R1 is connected with the negative electrode of the diode D1, one end of a resistor R2 is connected with the negative electrode of the resistor R1 and the negative electrode of the diode D1, the other end of the resistor R2 is connected with the b level of the triode QC5, the c level of the triode QC5 is connected with one ends of the MOS tube Q1 and the resistor R3, the other end of the resistor R3 is grounded and connected with the positive electrode of the diode D1, and the adapter is connected with the e level of the resistor R1 and the triode QC.
Furthermore, a voltage input end is arranged between the No. 1 pin of the adapter and the voltage stabilizing circuit, and one end, far away from the adapter, of the MOS tube Q1 is a voltage output end.
Further, pin number 2 and pin number 3 of the adapter are grounded.
Furthermore, the power switch circuit further comprises a capacitor C1, wherein one end of the capacitor C1 is connected with the pin No. 1 of the adapter, and the other end of the capacitor C1 is connected between the stage C of the triode QC5 and the resistor R3.
Further, the capacitor C1 is connected in parallel with the triode QC 5.
Furthermore, the c-stage of the triode QC5 is connected to the G terminal of the MOS transistor Q1, and the S terminal of the MOS transistor Q1 is connected to pin No. 1 of the adapter.
Further, the adapter model is DC-005.
Further, the model of the triode QC5 is 2N 3906.
Further, the MOS transistor Q1 has a model AO 3401.
Further, the model of the diode D1 is MM3Z5V 6B.
The utility model has the advantages that: the adapter is connected with the voltage stabilizing circuit, the voltage stabilizing circuit is connected with the power switch circuit, and when the input voltage is normal, the voltage stabilizing circuit does not work, and the circuit is normally conducted; when the input voltage exceeds the normal working voltage of the adapter, the voltage stabilizing circuit works to disconnect the power switch circuit so as to avoid burning out circuit elements due to overhigh voltage; therefore, the effect of protecting the circuit can be achieved through a simple circuit structure.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without undue limitation to the invention. In the drawings:
fig. 1 is a schematic structural diagram of the overvoltage protection circuit of the present invention.
Detailed Description
In order to make the technical solution of the present invention better understood, the technical solution of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall belong to the protection scope of the present invention.
As shown in fig. 1, the present invention provides an overvoltage protection circuit, which is connected to an adapter, and includes a voltage stabilizing circuit and a power switch circuit; the power switch circuit comprises resistors R2 and R3, a triode QC5 and an MOS tube Q1, the voltage stabilizing circuit comprises a diode D1 and a resistor R1, a resistor R1 is connected with the negative electrode of the diode D1, one end of a resistor R2 is connected with the negative electrodes of the resistor R1 and the diode D1, the other end of the resistor R2 is connected with the b-stage of the triode QC5, the c-stage of the triode QC5 is connected with a resistor R3 and the MOS tube Q1, the other end of the resistor R3 is grounded and connected with the positive electrode of the diode D1, and the No. 1 pin of the adapter is connected with the resistor R1, the e-stage of the triode QC 46.
In the embodiment, the voltage stabilizing circuit consists of a resistor R1 and a diode D1, the resistance value of the resistor R1 is 2K omega, and the model of the diode D1 can be MM3Z5V 6B; the power switch circuit comprises R2 with the resistance value of 2K omega, R3 with the resistance value of 5.1K omega, C1 with the capacitance of 0.1uf, a triode QC5 and an MOS tube Q1, wherein the model of the triode QC5 can be 2N3906, and the model of the MOS tube Q1 can be AO 3401.
In the embodiment, the anode of the diode D1 is connected to the resistor R3, the anode of the diode D1 is grounded to one end of the resistor R3, and the other end of the resistor R3 is connected to the c-stage of the transistor QC 5; the negative electrode of the diode D1 is connected with the resistor R1, and one end of the resistor R1, which is far away from the diode D1, is connected with the No. 1 pin of the adapter and the power switch circuit.
In the embodiment, one end of the resistor R2 is connected between the cathode of the diode D1 and the resistor R1, and the other end is connected to the b-stage of the transistor QC 5.
In the embodiment, one end of the capacitor C1 is connected with the pin 1 of the adapter, the other end of the capacitor C1 is connected between the stage C of the transistor QC5 and the resistor R3, and the capacitor C1 is connected in parallel with the transistor QC 5.
In the embodiment, the stage c of the transistor QC5 is connected to the terminal G of the MOS transistor Q1, and the terminal S of the MOS transistor Q1 is connected to the pin No. 1 of the adaptor.
In an embodiment, pins 2 and 3 of the adapter are grounded.
In this embodiment, the type of the adapter used is a 5V adapter of DC-055; a voltage input end is arranged between the No. 1 pin of the adapter and the voltage stabilizing circuit, and one end of the MOSQ1, which is far away from the adapter, is a voltage output end; when the input voltage is 5V, the diode D1 does not work, the cathode voltage of the diode is 5V, when the diode D1 does not work, no pressure difference exists between the level b and the level e of the triode QC5, the triode QC5 does not work, the level G voltage of the MOSQ1 is 0V, the pressure difference exists between the level G and the level S of the MOS tube Q1, the MOS tube Q1 is conducted, and the output voltage of the output end is 5V; when the voltage of the adapter inserted by mistake is more than 5V, for example, when the adapter inserted by mistake is 9V or 12V, the diode D1 works, the cathode voltage of the diode is still 5V at the moment, the voltage difference exists between the two ends of the b level and the e level of the triode QC5, the triode QC5 works, the c level and the e level of the triode QC5 are conducted, the voltage difference does not exist between the two ends of the G and the S of the MOS tube Q1 at the moment, the MOS tube Q1 does not work, the output end is disconnected, and therefore the effect that the protection circuit cannot be burnt out is achieved.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. An overvoltage protection circuit, the overvoltage protection circuit is connected with an adapter, characterized in that: the overvoltage protection circuit comprises a voltage stabilizing circuit and a power switch circuit; the power switch circuit comprises resistors R2 and R3, a triode QC5 and an MOS tube Q1, the voltage stabilizing circuit comprises a diode D1 and a resistor R1, the resistor R1 is connected with the negative electrode of the diode D1, one end of the resistor R2 is connected with the negative electrodes of a resistor R1 and a diode D1, the other end of the resistor R2 is connected with the b-stage of the triode QC5, the c-stage of the triode QC5 is connected with the MOS tube Q1 and one end of the resistor R3, the other end of the resistor R3 is grounded and connected with the positive electrode of the diode D1, and the adapter is connected with the e-stage of the resistor R1 and the triode QC5 and the MOS tube Q1.
2. The overvoltage protection circuit of claim 1, wherein: a voltage input end is arranged between the No. 1 pin of the adapter and the voltage stabilizing circuit, and one end, far away from the adapter, of the MOS tube Q1 is a voltage output end.
3. The overvoltage protection circuit of claim 1, wherein: and the No. 2 pin and the No. 3 pin of the adapter are grounded.
4. The overvoltage protection circuit of claim 1, wherein: the power switch circuit further comprises a capacitor C1, wherein one end of the capacitor C1 is connected with the pin No. 1 of the adapter, and the other end of the capacitor C1 is connected with the stage C of the triode QC5 and the resistor R3.
5. The overvoltage protection circuit of claim 4, wherein: the capacitor C1 is connected with the triode QC5 in parallel.
6. The overvoltage protection circuit of claim 1, wherein: the stage c of the triode QC5 is connected with the end G of the MOS tube Q1, and the end S of the MOS tube Q1 is connected with the pin No. 1 of the adapter.
7. The overvoltage protection circuit of claim 1, wherein: the adapter is DC-005 in model.
8. The overvoltage protection circuit of claim 1, wherein: the model of the triode QC5 is 2N 3906.
9. The overvoltage protection circuit of claim 1, wherein: the MOS tube Q1 is AO 3401.
10. The overvoltage protection circuit of claim 1, wherein: the model of the diode D1 is MM3Z5V 6B.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921136172.6U CN210053210U (en) | 2019-07-18 | 2019-07-18 | Overvoltage protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921136172.6U CN210053210U (en) | 2019-07-18 | 2019-07-18 | Overvoltage protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210053210U true CN210053210U (en) | 2020-02-11 |
Family
ID=69399150
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921136172.6U Active CN210053210U (en) | 2019-07-18 | 2019-07-18 | Overvoltage protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210053210U (en) |
-
2019
- 2019-07-18 CN CN201921136172.6U patent/CN210053210U/en active Active
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