CN215772532U - Overvoltage turn-off circuit - Google Patents
Overvoltage turn-off circuit Download PDFInfo
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- CN215772532U CN215772532U CN202022801985.1U CN202022801985U CN215772532U CN 215772532 U CN215772532 U CN 215772532U CN 202022801985 U CN202022801985 U CN 202022801985U CN 215772532 U CN215772532 U CN 215772532U
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Abstract
The utility model discloses an overvoltage turn-off circuit which comprises a first resistor R1, a second resistor R2, a voltage regulator tube Q1, a first triode Q2, a second triode Q3 and a voltage protection unit, wherein the first resistor R1 is connected with the second resistor R2; the cathode of the voltage regulator tube Q1 is connected with the input end, and the anode of the voltage regulator tube Q1 is grounded through a first resistor R1; an emitter of the first triode Q2 is connected with the input end, a collector of the first triode Q2 is connected with the output end, and a base of the first triode Q2 is connected with a collector of the second triode Q3 through a second resistor R2; the emitting set of the second triode Q3 is grounded, and the base of the second triode Q3 is connected with the anode of a voltage regulator tube Q1 through a voltage protection unit. According to the utility model, when the input voltage in the circuit exceeds the normal working voltage, the hardware shuts off the power supply, and the voltage is automatically recovered after being recovered to be normal, thereby performing related protection on the rear-stage circuit.
Description
Technical Field
The utility model relates to the field of protection circuits, in particular to an overvoltage turn-off circuit.
Background
Overvoltage protection is an important function of power supply circuits. The overvoltage protection mode is divided into two types: firstly, the intermittent protection type is also called automatic restart type, namely after overvoltage occurs, the protection circuit can be restarted after the power supply circuit is turned off for a short time, and if the overvoltage fault is not relieved, the power supply can repeatedly try to restart; and secondly, the self-locking type is adopted, when the voltage value reaches an overvoltage protection point, the protection circuit acts to close the chip, and the chip can recover to work only after the fault is removed and the power is re-electrified again. The two overvoltage protection modes are only one in the power supply circuit in general, and once the chip selection is completed or the circuit design is completed, the overvoltage protection mode is fixed and cannot be selectively configured according to the actual requirements in the application. It is a problem in the prior art how to achieve a highly reliable overvoltage protection with good versatility in various protection designs of electronic circuits.
At present, most of overvoltage protection measures generally adopt a mode that a power supply sends out a corresponding control signal to power off a mainboard or the power supply is powered off to stop working to perform overvoltage protection, and the above overvoltage protection mode has the following defects: because the speed of the power supply responding to the control signal is slow, if a certain electronic element of the power supply is burnt, the over-high power supply voltage output by the power supply can still be directly input to the electronic element of the mainboard, so that the electronic element of the mainboard is damaged, if the damaged mainboard is continuously used, parts such as a processor and an internal memory can be burnt, and the consequence is serious.
SUMMERY OF THE UTILITY MODEL
The utility model provides an overvoltage turn-off circuit which is used for solving the problems that a rear-stage circuit is burnt and damaged after the overvoltage turn-off circuit in the existing circuit.
The utility model is realized by the following technical scheme:
an overvoltage turn-off circuit comprises a voltage regulator tube Q1, a PNP triode Q2, an NPN triode Q2, an NPN triode Q3, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a resistor R5; the cathode of the voltage regulator tube Q1 and the emitter of the PNP triode Q2 are connected with a voltage input end, the anode of the voltage regulator tube Q1 is connected with one end of a resistor R1, the collector of the PNP triode Q2 is a voltage output end, the base of the PNP triode Q2 is connected with one end of a resistor R2 and one end of a resistor R6, the other end of the resistor R6 is connected with the emitter of the PNP triode Q2, the other end of the resistor R2 is connected with the collector of the NPN triode Q3, the base of the NPN triode Q3 is connected with the collector of the NPN triode Q4 through a fourth resistor R, the base of the NPN triode Q4 is connected with one end of the resistor R3, the other end of the resistor R3 is connected with the anode of the voltage regulator tube Q1, and the other ends of the emitter of the NPN triode Q3, the NPN triode Q4 and the resistor R1 are grounded.
Furthermore, the device also comprises a resistor R5, one end of the resistor R5 is connected with the other end of the resistor R4, and the other end of the resistor R5 is connected with the controller.
Further, the model of the PNP triode Q2 is BCP 53; the model of the NPN triode Q3 and the model of the NPN triode Q4 are MMBT 5551.
Further, the model of the voltage regulator tube Q1 is BZX84-B33 with the stable voltage of 33V.
Further, the resistances of the resistors R1, R2, R3, R4 and R5 are 10 k; the resistance R6 is 47K.
The utility model has the beneficial effects that: according to the utility model, when the input voltage in the circuit exceeds the normal working voltage, the hardware shuts off the power supply, and the voltage is automatically recovered after being recovered to be normal, thereby performing related protection on the rear-stage circuit.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
Fig. 1 is a schematic circuit diagram of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.
Example 1
As shown in fig. 1, an overvoltage shutdown circuit includes a voltage regulator Q1, a PNP transistor Q2, an NPN transistor Q2, an NPN transistor Q3, a resistor R1, R2, R3, R4, and R5; the cathode of the voltage regulator tube Q1 and the emitter of the PNP triode Q2 are connected with a voltage input end, the anode of the voltage regulator tube Q1 is connected with one end of a resistor R1, the collector of the PNP triode Q2 is a voltage output end, the base of the PNP triode Q2 is connected with one end of a resistor R2 and one end of a resistor R6, the other end of the resistor R6 is connected with the emitter of the PNP triode Q2, the other end of the resistor R2 is connected with the collector of the NPN triode Q3, the base of the NPN triode Q3 is connected with the collector of the NPN triode Q4 through a fourth resistor R, the base of the NPN triode Q4 is connected with one end of the resistor R3, the other end of the resistor R3 is connected with the anode of the voltage regulator tube Q1, and the other ends of the emitter of the NPN triode Q3, the NPN triode Q4 and the resistor R1 are grounded.
Furthermore, the device also comprises a resistor R5, one end of the resistor R5 is connected with the other end of the resistor R4, and the other end of the resistor R5 is connected with the controller.
Further, the model of the PNP triode Q2 is BCP 53; the model of the NPN triode Q3 and the model of the NPN triode Q4 are MMBT 5551.
Further, the model of the voltage regulator tube Q1 is BZX84-B33 with the stable voltage of 33V.
Further, the resistances of the resistors R1, R2, R3, R4 and R5 are 10 k; the resistance R6 is 47K.
Example 2
On the basis of the embodiment 1, the working principle flow is as follows:
the PNP transistor Q2 is tied to a high level on resistor R5 by the microcontroller so that the power input is output through PNP transistor Q2.
2. When the power input is higher than 33V, the voltage regulator tube Q1 is broken down, so that the NPN triode Q4 is conducted, and when the NPN triode Q4 is conducted, the PNP triode Q2 is closed, so that the overvoltage shutoff function is completed.
The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the utility model as claimed. The scope of the utility model is defined by the appended claims and equivalents thereof.
Claims (4)
1. An overvoltage turn-off circuit is characterized by comprising a voltage regulator tube Q1, a PNP triode Q2, an NPN triode Q2, an NPN triode Q3, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a resistor R5; the cathode of the voltage regulator tube Q1 and the emitter of the PNP triode Q2 are connected with a voltage input end, the anode of the voltage regulator tube Q1 is connected with one end of a resistor R1, the collector of the PNP triode Q2 is a voltage output end, the base of the PNP triode Q2 is connected with one end of a resistor R2 and one end of a resistor R6, the other end of the resistor R6 is connected with the emitter of the PNP triode Q2, the other end of the resistor R2 is connected with the collector of an NPN triode Q3, the base of the NPN triode Q3 is connected with the collector of an NPN triode Q4 through a fourth resistor R, the base of the NPN triode Q4 is connected with one end of the resistor R3, the other end of the resistor R3 is connected with the anode of a voltage regulator tube Q1, and the other ends of the emitter of the NPN triode Q3, the NPN triode Q4 and the resistor R1 are grounded; one end of the resistor R5 is connected with the other end of the resistor R4, and the other end of the resistor R5 is connected with the controller.
2. The overvoltage shutdown circuit of claim 1, wherein the PNP transistor Q2 is of the type BCP 53; the model of the NPN triode Q3 and the model of the NPN triode Q4 are MMBT 5551.
3. The overvoltage shutdown circuit of claim 1, wherein the regulator Q1 is model BZX84-B33 with a regulated voltage of 33V.
4. The overvoltage shutdown circuit of claim 1, wherein the resistors R1, R2, R3, R4 and R5 are 10 k; the resistance R6 is 47K.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022801985.1U CN215772532U (en) | 2020-11-27 | 2020-11-27 | Overvoltage turn-off circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022801985.1U CN215772532U (en) | 2020-11-27 | 2020-11-27 | Overvoltage turn-off circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN215772532U true CN215772532U (en) | 2022-02-08 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202022801985.1U Active CN215772532U (en) | 2020-11-27 | 2020-11-27 | Overvoltage turn-off circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN215772532U (en) |
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2020
- 2020-11-27 CN CN202022801985.1U patent/CN215772532U/en active Active
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