CN217643153U - Overcurrent and overvoltage protection circuit based on frequency control and switching power supply control system - Google Patents
Overcurrent and overvoltage protection circuit based on frequency control and switching power supply control system Download PDFInfo
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- CN217643153U CN217643153U CN202221347239.2U CN202221347239U CN217643153U CN 217643153 U CN217643153 U CN 217643153U CN 202221347239 U CN202221347239 U CN 202221347239U CN 217643153 U CN217643153 U CN 217643153U
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Abstract
The application discloses overcurrent and overvoltage protection circuit and switching power supply control system based on frequency control. The overcurrent and overvoltage protection circuit based on frequency control comprises a photoelectric detection circuit and a regulation and control circuit. The photoelectric detection circuit comprises a photoelectric detection unit which is electrically connected with a switching power supply so that the photoelectric detection unit can reflect an electric signal of the switching power supply. The regulating circuit is electrically connected to a control chip, the control chip is in telecommunication connection with the PWM wave of the switching power supply, and the regulating circuit is in signal connection with the photoelectric detection unit, so that when the regulating circuit detects that the electric signal of the switching power supply exceeds a preset value through the photoelectric detection unit, the regulating circuit reduces the frequency of the PWM wave output by the control chip, thereby reducing the purpose of outputting the electric signal by the switching power supply and achieving the purpose of overcurrent and overvoltage protection.
Description
Technical Field
The utility model relates to a control circuit technical field specifically is overcurrent overvoltage crowbar and switching power supply control system based on frequency control.
Background
The pulse width modulation is an analog control mode, the bias of a transistor base or an MOS transistor grid is modulated according to the change of corresponding load, so that the conduction time of the transistor or the MOS transistor is changed, and the output of the switching voltage-stabilized power supply is changed.
The current analog control circuit is provided with an overcurrent and overvoltage protection circuit which can reduce the voltage and the current of a power supply, prevent high voltage and high current from damaging electronic equipment and achieve the purpose of prolonging the service life of the circuit. However, the existing over-current and over-voltage protection circuit is too complex, a voltage detection circuit and a current detection circuit series circuit need to be added on the switching power supply, extra load is added on the switching power supply, the control circuit is difficult to implement, and the manufacturing cost of the circuit is increased.
SUMMERY OF THE UTILITY MODEL
The utility model has the advantages of an advantage of providing overcurrent and overvoltage protection circuit based on frequency control, wherein regulation and control circuit monitors switching power supply according to photoelectric detection circuit, can reduce the frequency of control chip output PWM frequency when switching power supply's signal of telecommunication surpasses the predetermined value to reduce switching power supply output signal of telecommunication's purpose, reach overcurrent and overvoltage protection's purpose.
For reaching the utility model discloses above at least one advantage, the utility model provides an excessive pressure protection circuit overflows based on frequency control, excessive pressure protection circuit overflows based on frequency control includes:
the photoelectric detection circuit comprises a photoelectric detection unit which is electrically connected with a switching power supply so as to enable the photoelectric detection unit to reflect an electric signal of the switching power supply; and
the control circuit is electrically connected to a control chip, the control chip is in telecommunication connection with the PWM wave of the switching power supply, and the control circuit is in signal connection with the photoelectric detection unit so that when the control circuit detects that the electric signal of the switching power supply exceeds a preset value through the photoelectric detection unit, the control circuit reduces the frequency of the PWM wave output by the control chip.
According to the utility model discloses an embodiment, regulation and control circuit reduces with the mode that reduces self resistance the frequency of control chip output PWM wave.
According to the utility model discloses an embodiment, regulation and control circuit includes a detecting element and a regulation and control unit, wherein the detecting element with the equal electric connection of regulation and control unit is in a control chip, control chip with switching power supply PWM ripples telecommunication connection, the detecting element with photoelectric detection unit signal connection, with the detecting element passes through photoelectric detection unit detects when switching power supply's signal of telecommunication exceeds the predetermined value, the detecting element makes the resistance of regulation and control unit reduces, can reduce the frequency of the PWM wave of control chip output
According to the utility model discloses an embodiment, photoelectric detection unit and detecting element are implemented a photodiode and a phototransistor that mutual optical signal connects, photodiode by electric connection in switching power supply, phototransistor by electric connection in control chip.
According to an embodiment of the present invention, the regulating unit is implemented as a triode and a resistance-adjusting resistor, and the triode is electrically connected to the control chip after being connected in series with the resistance-adjusting resistor;
the regulating circuit comprises a voltage dividing resistor and a fixed value resistor, wherein the voltage dividing resistor is connected in parallel with the photoelectric transistor, and the fixed value resistor is connected in parallel with the triode and the resistance adjusting resistor.
According to the utility model discloses an embodiment, the triode has a base, an emitter and a collecting electrode, wherein the base with divider resistance's one end electric connection, wherein the emitter with control chip electric connection, wherein the collecting electrode with resistance trimming resistance electric connection works as the emitter with when the collecting electrode switches on, resistance trimming resistance with fixed value resistance electric connection.
According to an embodiment of the present invention, the triode is implemented as an NPN-type triode.
According to the utility model discloses an embodiment, photoelectric detection circuit still includes at least shunt resistance, shunt resistance connect in parallel in photoelectric detection unit.
According to the utility model discloses an embodiment, photoelectric detection circuit still includes a protection electric capacity, protection electric capacity is parallelly connected in photoelectric detection unit.
For reaching the utility model discloses above at least one advantage, the utility model provides a switching power supply control system, a serial communication port, switching power supply control system with overcurrent and overvoltage protection includes:
a switching power supply;
the control chip is electrically connected with the switching power supply; and
according to the overcurrent and overvoltage protection circuit based on frequency control in any one of the embodiments, the overcurrent and overvoltage protection circuit based on frequency control is simultaneously electrically connected with the control chip and the switching power supply.
Drawings
Fig. 1 shows the electrical connection block diagram of the over-current and over-voltage protection circuit based on frequency control.
Detailed Description
The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The basic principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents and other technical solutions without departing from the spirit and scope of the invention.
It will be understood by those skilled in the art that in the present disclosure, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in a generic and descriptive sense only and not for purposes of limitation, as the terms are used in the description to indicate that the referenced device or element must have the specified orientation, be constructed and operated in the specified orientation, and not for the purpose of limitation.
It is understood that the terms "a" and "an" should be interpreted as meaning that a number of one element or element is one in one embodiment, while a number of other elements is one in another embodiment, and the terms "a" and "an" should not be interpreted as limiting the number.
Referring to fig. 1, an overcurrent and overvoltage protection circuit based on frequency control according to a preferred embodiment of the present invention will be described in detail below. The overcurrent and overvoltage protection circuit based on frequency control is suitable for various switching power supplies, can ensure that the switching power supplies output stable voltage and current, avoids damage of the overloaded voltage or current to the circuit, and prolongs the service life of the control circuit.
The overcurrent and overvoltage protection circuit based on frequency control comprises a photoelectric detection circuit 10 and a regulation and control circuit 20.
The photodetection circuit 10 is electrically connected to a switching power supply 100 for receiving the electrical signal transmitted from the switching power supply 100, and the photodetection circuit 10 includes a photodetection unit 11, and the photodetection unit 11 can reflect the magnitude of the electrical signal output by the switching power supply 100.
The control circuit 20 is electrically connected to a control chip 200, and the control chip 200 is in PWM wave telecommunication connection with the switching power supply 100. The control circuit 20 is in signal connection with the photodetecting unit 11, and the control circuit 20 can know the electrical signal of the switching power supply 100 through the photodetecting unit 11. When the regulation and control circuit 20 detects that the electrical signal of the switching power supply 100 exceeds a predetermined value through the photodetection unit 11, the regulation and control circuit 20 can reduce the frequency of the PWM wave output by the control chip 200.
Since the photodetection unit 11 can reflect the magnitude of the electrical signal output by the switching power supply 100, and when the electrical signal output by the switching power supply 100 is too large, the regulating and controlling circuit 20 can reduce the frequency of the PWM wave output by the control chip 200, thereby achieving the purpose of reducing the electrical signal output by the switching power supply 100.
The control circuit 20 includes a detecting element 21 and a control unit 22, wherein the detecting element 21 is electrically connected to the control unit 22, wherein the detecting element 21 is in signal connection with the photodetecting unit 11, and the detecting element 21 can receive the signal of the photodetecting unit 11, so that the control unit 22 can detect the electrical signal of the switching power supply 100 through the detecting element 21. When the voltage or the current output by the switching power supply 100 exceeds a predetermined value, the detection element 21 can know that the voltage or the current output by the switching power supply 100 exceeds the predetermined value through the photoelectric detection unit 11, at this time, the detection element 21 can send an electric signal to the regulation and control unit 22, when the regulation and control unit 22 receives the electric signal, the regulation and control unit 22 reduces the resistance value thereof, at this time, the frequency of the control chip 200 is reduced, so that the duty ratio of the PWM wave output by the control chip 200 is reduced, the switching power supply 100 enters a power limiting protection mode, and the voltage output by the switching power supply 100 is reduced. If the voltage outputted from the switching power supply 100 cannot normally supply power to the control chip 200, and the control chip 200 has the hiccup protection mode, the control chip 200 can restart itself and the switching power supply 100, thereby preventing the switching power supply 100 from outputting too high voltage or current.
The photo detection unit 11 and the detection element 21 are implemented as a photodiode and a phototransistor in signal connection with each other, the photodiode is electrically connected to the switching power supply 100, and the phototransistor is electrically connected to the control chip 200.
When the voltage or the current input to the photodetection unit 11 by the switching power supply 100 becomes large, the light signal emitted by the photodiode becomes large, so that the phototransistor receives too many light signals, and therefore, the resistance value inside the phototransistor is correspondingly reduced along with too many light signals, so that the regulation and control unit 22 can receive an electric signal, and therefore, the regulation and control unit 22 can correspondingly reduce the resistance value thereof, so as to control the frequency of the PWM wave output by the control chip 200, and further reduce the voltage or the current signal output by the switching power supply 100, thereby achieving the purpose of protecting the circuit.
The regulation unit 22 is implemented as a transistor Q1 and a resistance-adjusting resistor R6, and the transistor Q1 is electrically connected to the control chip 200 after being connected in series with the resistance-adjusting resistor R6.
The control circuit 20 further includes a voltage dividing resistor R1 and a constant value resistor R5. The divider resistor R1 is connected in parallel to the phototransistor, and the fixed resistor R5 is connected in parallel to the transistor Q1 and the resistor R6. The regulating circuit 20 is further described, when the resistance value of the phototransistor changes, the triode Q1 is turned on, so that a current can flow from the control chip 200 to the resistance adjusting resistor R6, and the resistance adjusting resistor R6 and the fixed resistor R5 are connected in parallel, thereby reducing the resistance value between the two resistance adjusting resistors R6 and the fixed resistor R5, and achieving the purpose of reducing the output frequency of the control chip 200.
More specifically, the triode Q1 has a base terminal B, an emitter terminal E and a collector terminal C, wherein the base terminal B is electrically connected to one terminal of the voltage dividing resistor R1, the emitter terminal E is electrically connected to the control chip 200, and the collector terminal C is electrically connected to the resistance adjusting resistor R6. When the resistance of the phototransistor is decreased, the current flowing through the voltage dividing resistor R1 is decreased, and therefore, the current flowing into the base terminal B of the triode Q1 is decreased, so that the current of the emitter terminal E can flow into the collector terminal C, and the resistance adjusting resistor R6 and the constant value resistor R5 are connected in parallel.
Specifically, when the phototransistor does not receive an excessive optical signal, the resistance of the phototransistor is not decreased and still has a higher resistance, so that the current of the voltage dividing resistor R1 connected in parallel with the phototransistor is not decreased and the transistor Q1 is not turned on. When the phototransistor receives an overlarge optical signal, the resistance value of the phototransistor is reduced, so that the current of the divider resistor R1 connected in parallel with the phototransistor is reduced, the current flowing into the triode Q1 from the divider resistor R1 is reduced, the triode Q1 is turned on, the resistance adjusting resistor R6 is connected in parallel with the constant resistor R5, the output frequency of the control chip 200 is changed, and when the current output by the switching voltage 100 is increased, the output frequency of the control chip 200 is immediately reduced, so that the purpose of protecting the circuit is achieved.
The transistor Q1 is implemented as an NPN-type transistor.
The photoelectric detection circuit 10 further includes at least one shunt resistor 12, and the shunt resistor 12 is connected in parallel to the photoelectric detection unit 11. Because the current that photoelectric detection unit 11 needs is relatively weak, and less current just can make photoelectric detection unit 11 switches on, shunt resistance 12 with photoelectric detection unit 11 is parallelly connected, can change and switch on photoelectric detection unit 11's current, improves photoelectric detection circuit 10's anti-interference performance.
The photodetection circuit 10 further includes a protection capacitor 13, the protection capacitor is connected in parallel to the photodetection unit 11, the photodetection unit 11 belongs to the electrostatic sensitive component, the protection capacitor can provide a leakage loop, and it is right to protect the photodetection unit 11 from static electricity, so as to improve the service life of the photodetection unit 11.
The switching power supply control system comprises a switching power supply 100, a control chip 200 and an overcurrent and overvoltage protection circuit based on frequency control. The switching power supply 100 is in telecommunication connection with the control chip 200, and the over-current and over-voltage protection circuit based on frequency control is simultaneously electrically connected with the control chip and the switching power supply. The switching power supply 100 can supply power to the control chip 200, and the control chip 200 can control the electrical signal output by the switching power supply 100. The switching power supply control system with overcurrent and overvoltage protection can prolong the service life of the circuit and ensure that the circuit can normally operate for a long time.
It will be understood by those skilled in the art that the embodiments of the present invention as described above and shown in the drawings are given by way of example only and are not limiting of the present invention. The advantages of the present invention are already complete and effectively realized. The functional and structural principles of the present invention have been shown and described in the embodiments without departing from the principles, embodiments of the present invention may have any deformation or modification.
Claims (10)
1. Overcurrent and overvoltage protection circuit based on frequency control, its characterized in that, overcurrent and overvoltage protection circuit based on frequency control includes:
the photoelectric detection circuit comprises a photoelectric detection unit which is electrically connected with a switching power supply so as to enable the photoelectric detection unit to reflect an electric signal of the switching power supply; and
the control circuit is electrically connected to a control chip, the control chip is in telecommunication connection with the PWM wave of the switching power supply, and the control circuit is in signal connection with the photoelectric detection unit so that when the control circuit detects that the electric signal of the switching power supply exceeds a preset value through the photoelectric detection unit, the control circuit reduces the frequency of the PWM wave output by the control chip.
2. The frequency control-based overcurrent and overvoltage protection circuit according to claim 1, wherein the regulation and control circuit reduces the frequency of the PWM wave output by the control chip in a manner of reducing self-resistance.
3. The frequency-control-based overcurrent and overvoltage protection circuit according to claim 2, wherein the regulation circuit comprises a detection element and a regulation unit, wherein the detection element and the regulation unit are both electrically connected to a control chip, the control chip is in telecommunication connection with the PWM wave of the switching power supply, and the detection element is in signal connection with the photodetection unit, so that when the detection element detects that the electrical signal of the switching power supply exceeds a predetermined value through the photodetection unit, the detection element reduces the resistance of the regulation unit, and the frequency of the PWM wave output by the control chip can be reduced.
4. The over-current and over-voltage protection circuit based on frequency control according to claim 3, wherein the photo-detection unit and the detection element are implemented as a photo-diode and a photo-transistor optically connected to each other, the photo-diode is electrically connected to the switching power supply, and the photo-transistor is electrically connected to the control chip.
5. The frequency-control-based overcurrent and overvoltage protection circuit according to claim 4, wherein the regulation and control unit is implemented as a triode and a resistance-adjusting resistor, and the triode is electrically connected to the control chip after being connected in series with the resistance-adjusting resistor;
the regulating circuit comprises a voltage dividing resistor and a fixed value resistor, wherein the voltage dividing resistor is connected in parallel with the photoelectric transistor, and the fixed value resistor is connected in parallel with the triode and the resistance adjusting resistor.
6. The frequency-control-based over-current and over-voltage protection circuit according to claim 5, wherein the transistor has a base, an emitter and a collector, wherein the base is electrically connected to one end of the voltage divider, wherein the emitter is electrically connected to the control chip, wherein the collector is electrically connected to the resistor, and when the emitter and the collector are turned on, the resistor is electrically connected to the fixed resistor.
7. The frequency-control-based overcurrent and overvoltage protection circuit according to claim 6, wherein the transistor is implemented as an NPN transistor.
8. The frequency-control-based overcurrent and overvoltage protection circuit according to claim 1, wherein the photodetection circuit further comprises at least one shunt resistor, and the shunt resistor is connected in parallel with the photodetection unit.
9. The frequency-control-based overcurrent and overvoltage protection circuit according to claim 1, wherein the photodetection circuit further comprises a protection capacitor, and the protection capacitor is connected in parallel with the photodetection unit.
10. Switching power supply control system, its characterized in that, switching power supply control system includes:
a switching power supply;
the control chip is electrically connected with the switching power supply; and
the over-current and over-voltage protection circuit based on frequency control as claimed in any one of claims 1 to 9, wherein the over-current and over-voltage protection circuit based on frequency control is electrically connected to the control chip and the switching power supply at the same time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221347239.2U CN217643153U (en) | 2022-05-23 | 2022-05-23 | Overcurrent and overvoltage protection circuit based on frequency control and switching power supply control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221347239.2U CN217643153U (en) | 2022-05-23 | 2022-05-23 | Overcurrent and overvoltage protection circuit based on frequency control and switching power supply control system |
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| Publication Number | Publication Date |
|---|---|
| CN217643153U true CN217643153U (en) | 2022-10-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221347239.2U Active CN217643153U (en) | 2022-05-23 | 2022-05-23 | Overcurrent and overvoltage protection circuit based on frequency control and switching power supply control system |
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| Country | Link |
|---|---|
| CN (1) | CN217643153U (en) |
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2022
- 2022-05-23 CN CN202221347239.2U patent/CN217643153U/en active Active
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