CN217824234U - Overvoltage protection circuit and electronic equipment - Google Patents
Overvoltage protection circuit and electronic equipment Download PDFInfo
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- CN217824234U CN217824234U CN202221163767.2U CN202221163767U CN217824234U CN 217824234 U CN217824234 U CN 217824234U CN 202221163767 U CN202221163767 U CN 202221163767U CN 217824234 U CN217824234 U CN 217824234U
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Abstract
The application discloses overvoltage crowbar and electronic equipment. The overvoltage protection circuit includes: the control end of the first switch circuit is connected with a preset voltage; one end of the first input control circuit is a charging port, and the other end of the first input control circuit is connected with the first communication end of the first switch circuit and used for transmitting the charging voltage accessed by the charging port to the first communication end of the first switch circuit; and the control end of the second switch circuit is connected with the second communication end of the first switch circuit, the first communication end of the second switch circuit is used for being connected with the charging circuit, and the second communication end of the second switch circuit is connected with the other end of the first input control circuit. Through the mode, the charging/power supply overvoltage protection can be realized, and the service life of the electronic equipment and the circuit board thereof is prolonged.
Description
Technical Field
The present application relates to the field of electronic technologies, and in particular, to an overvoltage protection circuit and an electronic device.
Background
In order to realize electric driving of a movable electronic device, such as an electric floating plate, it is necessary to charge the movable electronic device by a charger provided. However, in practical applications, a user may use other unmatched chargers to charge the electronic device, i.e., use an unsatisfactory charger to charge the electronic device.
The existing electronic equipment does not realize the circuit protection for charging the charger which does not meet the requirements, usually, overvoltage charging and the like of the electronic equipment can be caused, the circuit board inside the electronic equipment is directly damaged, and the service life of the electronic equipment is shortened.
SUMMERY OF THE UTILITY MODEL
The application provides an overvoltage protection circuit and electronic equipment to realize charging/power supply overvoltage protection and prolong the service life of the electronic equipment and a circuit board thereof.
In order to solve the technical problem, the application provides an overvoltage protection circuit. The overvoltage protection circuit includes: the control end of the first switch circuit is connected with a preset voltage; one end of the first input control circuit is a charging port, and the other end of the first input control circuit is connected with the first communication end of the first switch circuit and used for transmitting the charging voltage accessed by the charging port to the first communication end of the first switch circuit; and the control end of the second switch circuit is connected with the second communication end of the first switch circuit, the first communication end of the second switch circuit is used for being connected with the charging circuit, and the second communication end of the second switch circuit is connected with the other end of the first input control circuit.
Wherein, the first input control circuit includes: the control end of the third switch circuit is connected with the second communication end of the first switch circuit, the first communication end of the third switch circuit, as one end of the first input control circuit, is used as a charging port, and the second communication end of the third switch circuit, as the other end of the first input control circuit, is connected with the second communication end of the second switch circuit; the anode of the diode is connected with the first communication end of the third switch circuit, and the cathode of the diode is connected with the second communication end of the third switch circuit; the overvoltage protection circuit further includes: and when the charging port is not connected with the charging voltage, the second input control circuit controls the first communication end and the second communication end of the third switch circuit to be disconnected so as to prevent the voltage of the charging circuit from flowing back to the charging port.
Wherein, overvoltage crowbar still includes: and one end of the first clamping circuit is grounded, and the other end of the first clamping circuit is connected with the first switch circuit and used for providing preset voltage.
Wherein, the first clamp circuit includes: the anode of the first voltage-stabilizing tube is grounded, and the cathode of the first voltage-stabilizing tube is connected with the control end of the first switch circuit; one end of the first resistor is connected with the cathode of the first voltage-stabilizing tube, and the other end of the first resistor is connected with the first communication end of the first switch circuit.
Wherein, overvoltage crowbar still includes: and one end of the second clamping circuit is connected with the control end of the second switching circuit, and the other end of the second clamping circuit is connected with the second communication end of the second switching circuit, so that the voltage difference between the control end and the second communication end of the second switching circuit is ensured.
The first switch circuit comprises a PNP triode, the second switch circuit comprises a first PMOS (P-channel metal oxide semiconductor) tube, the third switch circuit comprises a second PMOS tube, the base electrode of the PNP triode is connected with preset voltage, the emitting electrode of the PNP triode is respectively connected with the source electrode of the first PMOS tube and the source electrode of the second PMOS tube, the collecting electrode of the PNP triode is respectively connected with the grid electrode of the first PMOS tube and the grid electrode of the second PMOS tube, the drain electrode of the second PMOS tube is a charging port, and the drain electrode of the first PMOS tube is connected with the charging circuit.
Wherein the second input control circuit comprises: and the base electrode of the NPN triode is connected with the charging port, the collector electrode of the NPN triode is connected with the grid electrode of the second PMOS tube, and the emitting electrode of the NPN triode is grounded.
Wherein the second input control circuit further comprises: and one end of the second resistor is connected with the base electrode of the NPN triode, and the other end of the second resistor is connected with the emitting electrode of the NPN triode.
Wherein, overvoltage crowbar still includes: and one end of the third resistor is connected with the grid electrode of the first PMOS tube, and the other end of the third resistor is connected with the collector electrode of the NPN triode.
Wherein, overvoltage crowbar still includes: one end of the fourth resistor is connected with the charging port, and the other end of the fourth resistor is connected with the base electrode of the NPN triode; one end of the fifth resistor is connected with the grid electrode of the first PMOS tube, and the other end of the fifth resistor is connected with the source electrode of the first PMOS tube; and/or a sixth resistor, wherein one end of the sixth resistor is connected with the preset voltage, and the other end of the sixth resistor is connected with the base electrode of the PNP triode.
In order to solve the technical problem, the application provides an electronic device. The electronic equipment comprises the overvoltage protection circuit.
Is different from the prior art: the overvoltage protection circuit of the present application includes: the first switch circuit, the first input control circuit and the second switch circuit; the control end of the first switch circuit is connected with a preset voltage; one end of the first input control circuit is a charging port, and the other end of the first input control circuit is connected with the first communication end of the first switch circuit and used for transmitting the charging voltage accessed by the charging port to the first communication end of the first switch circuit; the control end of the second switch circuit is connected with the second communication end of the first switch circuit, the first communication end of the second switch circuit is used for being connected with the charging circuit, and the second communication end of the second switch circuit is connected with the other end of the first input control circuit. The overvoltage protection circuit transmits charging voltage accessed by a charging port to a first switch circuit and a second switch circuit respectively through a first input control circuit, controls the first switch circuit to be disconnected through the charging voltage to control the second switch circuit to be connected, and transmits the charging voltage to the charging circuit (the charging circuit can be an energy storage circuit of electronic equipment or a circuit for supplying power to the energy storage circuit and other circuits) through the second switch circuit so as to store electric energy for the electronic equipment; or the first switch circuit is controlled to be switched on by the charging voltage so as to control the second switch circuit to be switched off, thereby stopping transmitting the charging voltage to the charging circuit. Therefore, the first switch circuit and the second switch circuit can be automatically controlled to be switched on and off according to the magnitude of the charging voltage, so that the charging or the power supply of the charging voltage to the charging circuit is automatically controlled according to the magnitude of the charging voltage, and the charging or the power supply is stopped. Therefore, when the charging voltage is larger than or equal to the sum of the preset voltage and the conducting voltage conducted by the first communication end and the second communication end of the first switch circuit, the charging voltage can be stopped to charge or supply power for the charging circuit, overvoltage charging or power supply is avoided, overvoltage protection of charging or power supply is achieved, and the service life of the electronic equipment and the circuit board of the electronic equipment is prolonged.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:
FIG. 1 is a schematic diagram of an embodiment of an overvoltage protection circuit according to the present application;
FIG. 2 is a schematic diagram of the circuit configuration of the embodiment of FIG. 1;
fig. 3 is a schematic structural diagram of an embodiment of an electronic device according to the present application.
Detailed Description
The present application will be described in further detail with reference to the following drawings and examples. It is to be noted that the following examples are only illustrative of the present application, and do not limit the scope of the present application. Likewise, the following examples are only some examples and not all examples of the present application, and all other examples obtained by a person of ordinary skill in the art without any inventive step are within the scope of the present application.
In the description of the embodiments of the present application, it should be noted that the terms "connected" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, unless explicitly stated or limited otherwise; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. Specific meanings of the above terms in the embodiments of the present application can be understood in specific cases by those of ordinary skill in the art.
In the embodiments of the present application, unless otherwise explicitly specified or limited, a first feature "on" or "under" a second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of an embodiment of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Moreover, various embodiments or examples and features of various embodiments or examples described in this specification can be combined and combined by one skilled in the art without being mutually inconsistent.
First, an overvoltage protection circuit is provided, as shown in fig. 1 and 2, fig. 1 is a schematic structural diagram of an embodiment of the overvoltage protection circuit; fig. 2 is a schematic circuit diagram of the embodiment of fig. 1. The overvoltage protection circuit (not shown) of the present embodiment includes: a first switch circuit 11, a first input control circuit 12, and a second switch circuit 13; wherein, the control end of the first switch circuit 11 is connected with a preset voltage V1; one end of the first input control circuit 12 is a charging port POW, and the other end of the first input control circuit 12 is connected to the first communication end of the first switch circuit 11, and is configured to transmit a charging voltage accessed by the charging port POW to the first communication end of the first switch circuit 11; the control terminal of the second switch circuit 13 is connected to the second communication terminal of the first switch circuit 11, the first communication terminal of the second switch circuit 13 is used for connecting to a charging circuit (not shown, the port VBAT), and the second communication terminal of the second switch circuit 13 is connected to the other end of the first input control circuit 12.
When the charging voltage is smaller than the threshold voltage, the first communication terminal and the second communication terminal of the first switch circuit 11 are disconnected, and the first communication terminal and the second communication terminal of the second switch circuit 13 are connected, so that the charging voltage is transmitted to the charging circuit to charge/supply power to the charging circuit.
When the charging voltage is greater than or equal to the threshold voltage, the first communication terminal and the second communication terminal of the first switch circuit 11 are turned on, and the first communication terminal and the second communication terminal of the second switch circuit 13 are turned off, so as to stop charging/supplying power to the charging circuit.
The threshold voltage is the sum of the preset voltage V1 and the turn-on voltage of the first communication terminal and the second communication terminal of the first switch circuit 11.
For example, in an application scenario, the preset voltage V1 may be 28V, the turn-on voltage for turning on the first communication terminal and the second communication terminal of the first switch circuit 11 may be 1V, and the threshold voltage is 29V; when the charging voltage is lower than 29V, the first communication terminal and the second communication terminal of the first switch circuit 11 are disconnected, and the first communication terminal and the second communication terminal of the second switch circuit 13 are connected, so as to transmit the charging voltage to the charging circuit for charging/supplying power to the charging circuit.
When the charging voltage is higher than or equal to 29V, the first communication terminal and the second communication terminal of the first switch circuit 11 are turned on, and the first communication terminal and the second communication terminal of the second switch circuit 13 are turned off, so as to stop charging/supplying power to the charging circuit.
The preset voltage V1 may be determined based on the performance parameters of the charging circuit and the power requirements of the electronic devices such as the electric floating plate, and is not particularly limited.
The magnitude of the turn-on voltage for turning on the first communication terminal and the second communication terminal of the first switch circuit 11 may be determined based on performance parameters of components for implementing the first switch circuit 11.
The charging circuit may be an energy storage circuit of an electronic device such as an electric floating plate, or a circuit for supplying power to the energy storage circuit and other circuits.
In the overvoltage protection circuit of the embodiment, the first input control circuit 12 transmits charging voltage accessed by the charging port POW to the first switch circuit 11 and the second switch circuit 13 respectively, and controls the first switch circuit 11 to be switched off through the charging voltage so as to control the second switch circuit 13 to be switched on, so that the charging voltage is transmitted to the charging circuit through the second switch circuit 13 to charge or supply power to electronic equipment such as an electric floating plate; or the first switch circuit is controlled to be turned on by the charging voltage to control the second switch circuit 13 to be turned off, thereby stopping the transfer of the charging voltage to the charging circuit. Therefore, the present embodiment can automatically control the on/off of the first switch circuit 11 and the second switch circuit 13 according to the magnitude of the charging voltage (specifically, the magnitude relation between the charging voltage and the threshold voltage (constant value)), so as to automatically control the charging or supplying of the charging circuit and the stopping of the charging or supplying of the charging circuit according to the magnitude of the charging voltage. Therefore, in this embodiment, when the charging voltage is greater than or equal to the sum of the preset voltage and the conduction voltage of the conduction of the first communication terminal and the second communication terminal of the first switch circuit 11, the charging voltage may be stopped to charge the charging circuit, so as to avoid overvoltage charging or power supply, implement overvoltage protection of charging or power supply, and improve the service life of the electronic device and the circuit board thereof.
Optionally, the first input control circuit 12 of the present embodiment includes: a third switch circuit (not shown) and a diode D; a control end of the third switch circuit is connected with a second communication end of the first switch circuit 11, a first communication end of the third switch circuit as one end of the first input control circuit 12 is a charging port POW, and a second communication end of the third switch circuit as the other end of the first input control circuit 12 is connected with a second communication end of the second switch circuit 13; the anode of the diode D is connected to the first communication terminal of the third switch circuit, and the cathode of the diode D is connected to the second communication terminal of the third switch circuit.
The diode D of the present embodiment may be a parasitic diode, for example, a parasitic diode in the following second PMOS transistor Q16.
Optionally, the overvoltage protection circuit of this embodiment further includes: and when the charging port POW does not receive the charging voltage, the second input control circuit 14 controls the first communication end and the second communication end of the third switch circuit to be disconnected, so that the voltage of the charging circuit is prevented from flowing back to the charging port POW.
When the charging voltage is needed to control the first switch circuit 11 to be turned off to control the second switch circuit 13 to be turned on, and the charging voltage is used to charge or supply power to the charging circuit, the charging voltage connected to the charging port POW can be transmitted to the first switch circuit 11 and the second switch circuit 13 through the diode D of the first input control circuit 12.
When charging is not needed, the charging port POW is disconnected, the charging port POW is not connected, and at this time, the second input control circuit 14 is not conducted, so that the third switch circuit is disconnected, and the voltage of the charging circuit (port VBAT) is prevented from being reversely charged to the charging port POW by the third switch circuit.
Optionally, the first switch circuit 11 of this embodiment includes a PNP transistor Q15, the second switch circuit 13 includes a first PMOS transistor Q17, and the third switch circuit includes a second PMOS transistor Q16, wherein a base of the PNP transistor Q15 (i.e., the control terminal of the first switch circuit 11) is connected to the preset voltage, an emitter of the PNP transistor Q15 (i.e., the first communication terminal of the first switch circuit 11) is connected to a source of the first PMOS transistor Q17 (i.e., the second communication terminal of the second switch circuit 13) and a source of the second PMOS transistor Q16 (i.e., the second communication terminal of the third switch circuit), respectively, a collector of the PNP transistor Q15 (i.e., the second communication terminal of the first switch circuit 11) is connected to a gate of the first PMOS transistor Q17 (i.e., the control terminal of the second switch circuit 13) and a gate of the second PMOS transistor Q16 (i.e., the control terminal of the third switch circuit), respectively, a drain of the second PMOS transistor Q16 (i.e., the first communication terminal of the third switch circuit) is a POW, and a drain of the first PMOS transistor Q17 is connected to the second communication terminal of the charge circuit.
It should be noted that the second PMOS transistor Q16 of the present embodiment includes the diode D, and the switching function of the third switching circuit is realized by the switching transistor in the second PMOS transistor Q16, i.e. the third switching circuit only corresponds to the switching transistor in the second PMOS transistor Q16. Of course, in other embodiments, the diode D and the third switch circuit may be implemented by separate diodes and switch tubes.
Optionally, the second input control circuit 14 of the present embodiment includes: and a base electrode of the NPN triode Q18 is connected with the charging port POW, a collector electrode of the NPN triode Q18 is connected with a grid electrode of the second PMOS tube Q16, and an emitting electrode of the NPN triode Q18 is grounded.
When charging is not needed, the charging port POW is disconnected, the charging port POW is not connected, at the moment, the NPN triode Q18 is not conducted, current of the charging circuit passes through the parasitic diode of the first PMOS tube Q17 from the port VBAT, a part of current flows from the source electrode of the first PMOS tube Q17 to the source electrode of the second PMOS tube Q16, and a part of current flows from the source electrode of the first PMOS tube Q17 to the gate electrode of the second PMOS tube Q16 through the fifth resistor R54. The potential of the source of the second PMOS transistor Q16 is approximately equal to the voltage of the port VBAT, and the potential of the gate of the second PMOS transistor Q16 is also approximately equal to the voltage of the port VBAT (the fifth resistor R54 and the second voltage regulator D2 have negligible effect on the potentials), and there is substantially no potential difference between the two, so that the second PMOS transistor Q16 is not turned on, and the voltage of the charging circuit (the port VBAT) can be prevented from flowing backwards from the third switch circuit to the charging port POW.
Optionally, the overvoltage protection circuit of this embodiment further includes: and one end of the first clamping circuit 15 is grounded, and the other end of the first clamping circuit 15 is connected with the first switch circuit 11 and used for providing a preset voltage.
The first clamp circuit 15 of the present embodiment includes: a first voltage regulator tube D1 and a first resistor R4; the anode of the first voltage-regulator tube D1 is grounded, and the cathode of the first voltage-regulator tube D1 is connected with the control end of the first switch circuit 11; one end of the first resistor R4 is connected to the cathode of the first voltage regulator D1, and the other end of the first resistor R4 is connected to the first communication end of the first switch circuit 11.
The purpose of voltage stabilization can be achieved by reversely connecting the first voltage stabilizing tube D1.
In an application scenario, the first switch circuit 11 may be implemented by a PNP triode Q15, a cathode of the first voltage regulator D1 is connected to a base of the PNP triode Q15, and the other end of the first resistor R4 is connected to an emitter of the PNP triode Q15.
In this embodiment, the clamp circuit for presetting the voltage is implemented by the first voltage regulator tube D1 and the first resistor R4, so that the circuit structure can be simplified, and the cost can be saved. Of course, in other embodiments, other circuits may be used to implement the first clamping circuit 15 of the present embodiment.
Further, the first voltage regulator tube D1 is connected in series with the first resistor R4, so that the current of the first voltage regulator tube D1 in the reverse direction can be prevented from being too large, and the current can be limited by the first resistor R4.
Optionally, the overvoltage protection circuit of this embodiment further includes: one end of the sixth resistor R12 is connected with a preset voltage, and the other end of the sixth resistor R12 is connected with the base electrode of the PNP triode Q15. The sixth resistor R12 is at least used for limiting the current of the base of the PNP transistor Q15. In this embodiment, one end of the sixth resistor R12 is connected to the cathode of the first voltage regulator D1, and the other end of the sixth resistor R12 is connected to the base of the PNP triode Q15.
In the above application scenario, when the charger is inserted into the charging port POW to charge or supply power to the charging circuit, if the charging voltage is less than 29V, the collector and the emitter of the PNP triode Q15 are not conducted, the drain and the source of the first PMOS transistor Q17 are conducted, and the charging voltage charges or supplies power to the electronic device from the port VBAT through the drain and the source of the first PMOS transistor Q17; the voltage stabilizing value of the first voltage stabilizing tube D1 is 28V, so that the potential of the base electrode of the PNP triode Q15 can be fixed at 28V in the circuit, when the potential difference between the emitter electrode and the base electrode of the PNP triode Q15 is greater than or equal to 1V, the collector electrode and the emitter electrode of the PNP triode Q15 are conducted, and the potential of the collector electrode of the PNP triode Q15 is determined by the charging voltage; if the charging voltage is higher than or equal to 29v, the collector and the emitter of the pnp triode Q15 are turned on, and the drain and the source of the first PMOS transistor Q17 are no longer turned on, at this time, the charging voltage cannot charge or supply power to the electronic device from the port VBAT through the second PMOS transistor Q16 and the first PMOS transistor Q17, so that the purpose of avoiding the user from using an unsatisfactory charger can be achieved.
Further, when the charging port POW is not connected to the charging voltage, the parasitic diode of the first PMOS transistor Q17 can sink the internal voltage of the electronic device from the port VBAT to the second PMOS transistor Q16, but since the base of the NPN transistor Q18 is not connected to the voltage, the collector and the emitter of the NPN transistor Q18 are not connected to each other, and the source and the drain of the second PMOS transistor Q16 are not connected to each other, it is possible to control the second PMOS transistor Q16 to be not connected to each other when the charger is not inserted into the charging port POW, and it is possible to prevent the internal voltage of the electronic device such as the electric float from being sink to the charging port POW from the port VBAT.
Optionally, the second input control circuit 14 of this embodiment further includes: and one end of the second resistor R63 is connected with the base electrode of the NPN triode Q18, and the other end of the second resistor R63 is connected with the emitter electrode of the NPN triode Q18. The second resistor R63 is at least used for pulling down the base potential of the NPN triode Q18 to prevent the NPN triode Q18 from being turned on by mistake.
Optionally, the overvoltage protection circuit of this embodiment further includes: one end of the fourth resistor R62 is connected to the charging port POW, and the other end of the fourth resistor R62 is connected to the base of the NPN transistor Q18. The fourth resistor R62 is at least used for limiting the current of the base of the NPN transistor Q18.
Optionally, the overvoltage protection circuit of this embodiment further includes: and one end of the second clamping circuit 16 is connected to the control end of the second switch circuit 13, and the other end of the second clamping circuit 16 is connected to the second communication end of the second switch circuit 13, so as to ensure a voltage difference between the control end and the second communication end of the second switch circuit 13. In this way, the stability of the operation of the second switch circuit 13 can be improved, and the stability of the operation of the overvoltage protection circuit can be further improved.
Wherein the second clamp circuit 16 includes: and the anode of the second voltage-regulator tube D2 is connected with the grid electrode of the first PMOS tube Q17, and the cathode of the second voltage-regulator tube D2 is connected with the source electrode of the first PMOS tube Q17, so that the voltage difference between the grid electrode and the source electrode of the first PMOS tube Q17 is ensured, and the first PMOS tube Q17 is maintained to be stably conducted.
Optionally, the overvoltage protection circuit of this embodiment further includes: one end of the fifth resistor R54 is connected to the gate of the first PMOS transistor Q17, and the other end of the fifth resistor R54 is connected to the source of the first PMOS transistor Q17. The fifth resistor R54 is used at least for voltage division.
Optionally, the overvoltage protection circuit of this embodiment further includes: and one end of the third resistor R61 is connected to the gate of the first PMOS transistor Q17, and the other end of the third resistor R61 is connected to the collector of the NPN triode Q18.
Under normal charging (with a compliant charger), the third resistor R61 acts as a voltage divider. The PNP transistor Q15 is turned off, and the current of the charger flows from the charging port POW to the second PMOS transistor Q16, from the source to the drain of the second PMOS transistor Q16 to the source of the first PMOS transistor Q17, and part passes through the fifth resistor R54 to the third resistor R61, passes through the NPN transistor Q18 (in a conducting state), and then to ground. The third resistor R61 functions as a voltage divider to ensure that the potential difference between the gate and the source of the first PMOS transistor Q17 cannot be too large to ensure the normal operation of the first PMOS transistor Q17.
During abnormal charging (an unconventional charger), the third resistor R61 plays a role in limiting current, the PNP triode Q15 is conducted, the current of the charger flows to the diode D from the charging port POW, then to the emitting electrode of the PNP triode Q15 and then to the collecting electrode of the PNP triode Q15, the current flows to the third resistor R61 along the path and then to the ground through the NPN triode Q18, the third resistor R61 can prevent the current of the loop from being too large, and the PNP triode Q15 and the NPN triode Q18 are prevented from being burnt out.
The third resistor R61 is connected with the second voltage-regulator tube D2 in series, the second voltage-regulator tube D2 is connected in reverse to show the voltage-stabilizing effect, but when the second voltage-regulator tube D2 is in reverse, the current flowing through the second voltage-regulator tube cannot be too large, and the third resistor R61 can play a role in limiting the current of the second voltage-regulator tube D2.
In other embodiments, any one or any combination of the first to sixth resistors may be selectively provided.
In other embodiments, other kinds of switching tubes can be used to replace the switching tubes, or other kinds of switching tubes (P-channel, N-channel) of the same kind can be used to replace the switching terminals, and the circuit can be adapted.
The present application further provides an electronic device, as shown in fig. 3, fig. 3 is a schematic structural diagram of an embodiment of the electronic device of the present application. The electronic device (not shown) of the present embodiment includes an overvoltage protection circuit 31. The structure and operation principle of the overvoltage protection circuit 31 can be referred to the above embodiments.
Optionally, the electronic device of this embodiment further includes a charging circuit 32 and an energy storage circuit 33, where the charging circuit 32 and the overvoltage protection circuit 31 may be disposed on a control board 34 of the electronic device; the overvoltage protection circuit 31 is connected to the charging circuit 32, and the overvoltage protection circuit 31 supplies a charging voltage to the charging circuit 32, so that the charging circuit 32 supplies power to the control board 34 and charges the energy storage circuit 33. The tank circuit 33 may be a battery or the like.
The electronic equipment can be an electric floating plate or other electronic equipment needing to be charged by a charger.
Being different from the prior art, the overvoltage protection circuit of this application includes: the first switch circuit, the first input control circuit and the second switch circuit; the control end of the first switch circuit is connected with a preset voltage; one end of the first input control circuit is a charging port, and the other end of the first input control circuit is connected with the first communication end of the first switch circuit and used for transmitting charging voltage accessed by the charging port to the first communication end of the first switch circuit; the control end of the second switch circuit is connected with the second communication end of the first switch circuit, the first communication end of the second switch circuit is used for being connected with the charging circuit, and the second communication end of the second switch circuit is connected with the other end of the first input control circuit. The overvoltage protection circuit transmits charging voltage accessed by a charging port to a first switch circuit and a second switch circuit respectively through a first input control circuit, controls the first switch circuit to be disconnected through the charging voltage, and controls the second switch circuit to be connected, so that the charging voltage is transmitted to the charging circuit through the second switch circuit (the charging circuit can be an energy storage circuit of electronic equipment, or a circuit for supplying power to the energy storage circuit and other circuits) to store electric energy for the electronic equipment; or the first switch circuit is controlled to be switched on by the charging voltage so as to control the second switch circuit to be switched off, thereby stopping transmitting the charging voltage to the charging circuit. Therefore, the first switch circuit and the second switch circuit can be automatically controlled to be switched on and off according to the magnitude of the charging voltage, so that the charging or the power supply of the charging voltage to the charging circuit is automatically controlled according to the magnitude of the charging voltage, and the charging or the power supply is stopped. Therefore, when the charging voltage is larger than or equal to the sum of the preset voltage and the conducting voltage conducted by the first communication end and the second communication end of the first switch circuit, the charging voltage can be stopped to charge or supply power for the charging circuit, overvoltage charging or power supply is avoided, overvoltage protection of charging or power supply is achieved, and the service life of the electronic equipment and the circuit board of the electronic equipment is prolonged.
The above description is only for the purpose of illustrating embodiments of the present application and is not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the specification and the drawings of the present application or are directly or indirectly applied to other related technical fields, are also included in the scope of the present application.
Claims (11)
1. An overvoltage protection circuit, comprising:
the control end of the first switch circuit is connected with a preset voltage;
the charging circuit comprises a first input control circuit, a second input control circuit and a first switching circuit, wherein one end of the first input control circuit is a charging port, and the other end of the first input control circuit is connected with a first communication end of the first switching circuit and used for transmitting charging voltage accessed by the charging port to the first communication end of the first switching circuit;
and the control end of the second switch circuit is connected with the second communication end of the first switch circuit, the first communication end of the second switch circuit is used for being connected with the charging circuit, and the second communication end of the second switch circuit is connected with the other end of the first input control circuit.
2. The overvoltage protection circuit of claim 1, wherein the first input control circuit comprises:
a third switch circuit, a control terminal of which is connected to a second communication terminal of the first switch circuit, a first communication terminal of which is used as the one terminal of the first input control circuit and is the charging port, and a second communication terminal of which is used as the other terminal of the first input control circuit and is connected to a second communication terminal of the second switch circuit;
a diode, an anode of the diode being connected to the first communication terminal of the third switching circuit, and a cathode of the diode being connected to the second communication terminal of the third switching circuit;
the overvoltage protection circuit further comprises:
and one end of the second input control circuit is connected with the charging port, the other end of the second input control circuit is connected with the second communication end of the third switch circuit, and when the charging port is not connected with the charging voltage, the second input control circuit controls the first communication end and the second communication end of the third switch circuit to be disconnected so as to prevent the voltage of the charging circuit from reversely flowing to the charging port.
3. The overvoltage protection circuit of claim 1, further comprising:
and one end of the first clamping circuit is grounded, and the other end of the first clamping circuit is connected with the first switch circuit and used for providing the preset voltage.
4. The overvoltage protection circuit of claim 3, wherein the first clamping circuit comprises:
the anode of the first voltage-regulator tube is grounded, and the cathode of the first voltage-regulator tube is connected with the control end of the first switch circuit;
one end of the first resistor is connected with the cathode of the first voltage regulator tube, and the other end of the first resistor is connected with the first communication end of the first switch circuit.
5. The overvoltage protection circuit of claim 1, further comprising:
and one end of the second clamping circuit is connected with the control end of the second switching circuit, and the other end of the second clamping circuit is connected with the second communication end of the second switching circuit, so as to ensure the voltage difference between the control end and the second communication end of the second switching circuit.
6. The overvoltage protection circuit of claim 2, wherein the first switch circuit comprises a PNP transistor, the second switch circuit comprises a first PMOS transistor, and the third switch circuit comprises a second PMOS transistor, wherein a base of the PNP transistor is connected to the preset voltage, an emitter of the PNP transistor is connected to a source of the first PMOS transistor and a source of the second PMOS transistor, respectively, a collector of the PNP transistor is connected to a gate of the first PMOS transistor and a gate of the second PMOS transistor, respectively, a drain of the second PMOS transistor is the charging port, and a drain of the first PMOS transistor is connected to the charging circuit.
7. The overvoltage protection circuit of claim 6, wherein the second input control circuit comprises:
and a base electrode of the NPN triode is connected with the charging port, a collector electrode of the NPN triode is connected with a grid electrode of the second PMOS tube, and an emitting electrode of the NPN triode is grounded.
8. The overvoltage protection circuit of claim 7, wherein the second input control circuit further comprises:
one end of the second resistor is connected with the base electrode of the NPN triode, and the other end of the second resistor is connected with the emitting electrode of the NPN triode.
9. The overvoltage protection circuit of claim 7, further comprising:
one end of the third resistor is connected with the grid electrode of the first PMOS tube, and the other end of the third resistor is connected with the collector electrode of the NPN triode.
10. The overvoltage protection circuit of claim 7, further comprising:
one end of the fourth resistor is connected with the charging port, and the other end of the fourth resistor is connected with the base electrode of the NPN triode; and/or
One end of the fifth resistor is connected with the grid electrode of the first PMOS tube, and the other end of the fifth resistor is connected with the source electrode of the first PMOS tube; and/or
And one end of the sixth resistor is connected to the preset voltage, and the other end of the sixth resistor is connected with the base of the PNP triode.
11. An electronic device comprising the overvoltage protection circuit of any one of claims 1 to 10.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221163767.2U CN217824234U (en) | 2022-05-13 | 2022-05-13 | Overvoltage protection circuit and electronic equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221163767.2U CN217824234U (en) | 2022-05-13 | 2022-05-13 | Overvoltage protection circuit and electronic equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217824234U true CN217824234U (en) | 2022-11-15 |
Family
ID=83984375
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221163767.2U Active CN217824234U (en) | 2022-05-13 | 2022-05-13 | Overvoltage protection circuit and electronic equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217824234U (en) |
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2022
- 2022-05-13 CN CN202221163767.2U patent/CN217824234U/en active Active
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