CN214315082U - Quick reset circuit used after power failure of switching power supply - Google Patents
Quick reset circuit used after power failure of switching power supply Download PDFInfo
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- CN214315082U CN214315082U CN202120556627.0U CN202120556627U CN214315082U CN 214315082 U CN214315082 U CN 214315082U CN 202120556627 U CN202120556627 U CN 202120556627U CN 214315082 U CN214315082 U CN 214315082U
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Abstract
The utility model relates to a switching power supply technical field discloses a quick reset circuit for switching power supply after outage, including full-wave rectifier circuit, discharge circuit, energy storage circuit, diode D3, control switch and PWM control chip, full-wave rectifier circuit converts the alternating voltage of input into direct voltage, full-wave rectifier circuit charges to energy storage circuit when full-wave rectifier circuit inputs alternating voltage, when full-wave rectifier circuit does not input alternating voltage, energy storage circuit discharges through discharge circuit, energy storage circuit is connected with diode D3's negative pole electricity, diode D3's positive pole is connected with control switch's control end electricity, control switch's input is connected with PWM control chip's power pin electricity, control switch's output ground connection, in the time of the actual use, if switching power supply cuts off the alternating current, PWM control chip's power pin voltage can reduce below the reset voltage rapidly, the PWM control chip is reset, and the switching power supply can be normally used when being powered on immediately after being powered off.
Description
Technical Field
The utility model belongs to the technical field of switching power supply technique and specifically relates to a quick reset circuit for switching power supply after outage.
Background
In the field of industrial automation or charging, a switching power supply or a charger is often used to convert voltage to convert ac power to dc power, and the dc voltage output by the switching power supply or the charger is controlled by a PWM IC, and the operating voltage of the PWM IC is also converted from ac power through a voltage conversion circuit. When a traditional switching power supply encounters faults such as overcurrent and overvoltage, the PWM IC can enter a Latch protection state, after an alternating current input end is pulled out, due to the energy storage effect of an internal capacitor, the voltage of a power port of the PWM IC cannot be rapidly reduced to be below a reset voltage, when the switching power supply or a charger is connected with an alternating current input again, the PWMIC is still in the Latch protection state, and the switching power supply cannot output the voltage.
SUMMERY OF THE UTILITY MODEL
In view of the not enough of background art, the utility model provides a quick reset circuit for after switching power supply outage, the technical problem that solve is PWM IC among voltage conversion equipment such as current switching power supply because overcurrent or behind the fault entering Latch guard state such as excessive pressure, the voltage of PWM IC's power end can not descend fast, after switching power supply inserts AC input again immediately after pulling out AC input end, PWMIC still is in Latch guard state, the unable output voltage of switching power supply.
For solving the technical problem, the utility model provides a following technical scheme: the utility model provides a quick reset circuit for after switching power supply outage, including full wave rectifier circuit, discharge circuit, tank circuit, diode D3, control switch and PWM control chip, full wave rectifier circuit converts the alternating voltage of input into DC voltage, full wave rectifier circuit charges to tank circuit when full wave rectifier circuit input alternating voltage, when full wave rectifier circuit does not have input alternating voltage, tank circuit discharges through discharge circuit, tank circuit's discharge voltage output end and diode D3's negative pole electricity are connected, diode D3's positive pole is connected with control switch's control end electricity, control switch's input is connected with PWM control chip's power pin electricity, control switch's output ground connection.
Optionally, in a certain embodiment, the control switch is a PNP triode Q1, and the collector of the PNP triode Q1 is grounded.
Optionally, in an embodiment, the full-wave rectification circuit includes diodes D1 and D2, an anode of the diode D1 is electrically connected to the ac input terminal L, a cathode of the diode D1 is electrically connected to the ac input terminal N, and cathodes of the diodes D1 and D2 are electrically connected to the energy storage circuit and the discharge circuit, respectively.
Optionally, in a certain embodiment, the energy storage circuit includes an electrolytic capacitor EC1, an anode of the electrolytic capacitor EC1 is electrically connected to a cathode of the diode D1, a cathode of the diode D2, and a cathode of the diode D3, respectively, and a cathode of the electrolytic capacitor EC1 is grounded.
Optionally, in a certain embodiment, the discharge circuit includes a resistor R1, one end of the resistor R1 is electrically connected to the anode of the electrolytic capacitor EC1, and the other end of the resistor R1 is grounded.
The working principle of the utility model is as follows: when the full-wave rectifying circuit inputs alternating current, the alternating current is rectified by diodes D1 and D2 and connected to the cathode of a diode D3, an electrolytic capacitor EC1 plays a role in storing electric energy, voltage at a power supply pin of the PWM control chip is connected to the anode of a diode D3 through a PN joint of a PNP triode Q1, the voltage at the cathode of the diode D3 is far greater than the voltage at the anode of the diode D3, the diode D3 is in a cut-off state, therefore, the CE electrode of the PNP triode Q1 is disconnected, the voltage at the power supply pin of the PWM control chip can normally supply power for the PWM control chip, the switching power supply normally works, and the output end has voltage output.
When the full-wave rectifying circuit has no AC input, the electric energy stored in the electrolytic capacitor EC1 is rapidly discharged through the resistor R1, the voltage of the negative terminal of the diode D3 is rapidly reduced, when the sum of the voltage of the cathode end of the diode D3 and the voltage drop of the diode D3 is smaller than the voltage of the anode end of the diode D3, the diode D3 is conducted, the sum of the voltage of the B electrode of the PNP triode Q1 and the voltage of the PN node of the BE is smaller than the voltage of the power pin of the PWM control chip, the CE electrode of the PNP triode Q1 is conducted, the voltage of the power pin of the PWM control chip is connected with the primary ground through the CE electrode of the PNP triode Q1 and the discharge resistor R2, the voltage of the power pin of the PWM control chip rapidly drops below the reset voltage of the PWM control chip, the PWM control chip resets, the switching power supply is enabled to reset quickly after power failure, and after the switching power supply is connected to the alternating current input end again in a short time, the switching power supply can still output voltage normally, and the user experience is greatly improved.
Compared with the prior art, the utility model beneficial effect who has is: after the alternating current input is cut off by a voltage conversion device such as a switching power supply, the voltage at the power pin of the PWM control chip is rapidly reduced to be lower than the reset voltage of the PWM control chip, and the PWM control chip is reset, so that when the alternating current is immediately accessed after the alternating current is cut off by the switching power supply, the PWM control chip can normally work, and the switching power supply can normally output the voltage.
Drawings
The utility model discloses there is following figure:
fig. 1 is a circuit diagram of the present invention.
Detailed Description
The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic drawings and illustrate the basic structure of the present invention only in a schematic manner, and thus show only the components related to the present invention.
As shown in fig. 1, a fast reset circuit for a switching power supply after power failure includes a full-wave rectifier circuit 1, a discharge circuit 3, an energy storage circuit 2, a diode D3, a control switch and a PWM control chip U1, where the full-wave rectifier circuit 1 converts an input ac voltage into a dc voltage, the full-wave rectifier circuit 1 charges the energy storage circuit 2 when the full-wave rectifier circuit 1 inputs the ac voltage, when the full-wave rectifier circuit 1 does not input the ac voltage, the energy storage circuit 2 discharges through the discharge circuit 3, a discharge voltage output end of the energy storage circuit 2 is electrically connected to a cathode of the diode D3, an anode of the diode D3 is electrically connected to a control end of the control switch, an input end of the control switch is electrically connected to a power pin of the PWM control chip U1, and an output end of the control switch is grounded.
Specifically, in this embodiment, the control switch is a PNP triode Q1, and the collector of the PNP triode Q1 is grounded.
Specifically, in the present embodiment, the full-wave rectification circuit 1 includes diodes D1 and D2, the anode of the diode D1 is electrically connected to the ac input terminal L, the cathode of the diode D1 is electrically connected to the ac input terminal N, and the cathodes of the diodes D1 and D2 are electrically connected to the tank circuit and the discharge circuit, respectively.
Specifically, in the present embodiment, the energy storage circuit 2 includes an electrolytic capacitor EC1, the anode of the electrolytic capacitor EC1 is electrically connected to the cathode of the diode D1, the cathode of the diode D2, and the cathode of the diode D3, respectively, and the cathode of the electrolytic capacitor EC1 is grounded.
Specifically, in this embodiment, the discharge circuit includes a resistor R1, one end of the resistor R1 is electrically connected to the positive electrode of the electrolytic capacitor EC1, and the other end of the resistor R1 is grounded.
The working principle of the utility model is as follows: when the full-wave rectifying circuit 1 inputs alternating current, the alternating current is rectified by diodes D1 and D2 and connected to the cathode of a diode D3, an electrolytic capacitor EC1 plays a role in storing electric energy, the voltage VCC at the power supply pin of the PWM control chip U1 is connected to the anode of a diode D3 through a PN joint of a PNP triode Q1, the voltage at the cathode of the diode D3 is far greater than the voltage at the anode of the diode D3, and the diode D3 is in a cut-off state, so that the CE electrode of the PNP triode Q1 is disconnected, the voltage at the power supply pin of the PWM control chip U1 can normally supply power for the PWM control chip U1, the switching power supply normally works, and the output end has voltage output.
When the full-wave rectifying circuit 1 has no AC input, the electric energy stored in the electrolytic capacitor EC1 is rapidly released through the resistor R1, the voltage at the negative terminal of the diode D3 is rapidly reduced, when the sum of the voltage at the negative terminal of the diode D3 and the voltage drop of the diode D3 is smaller than the voltage at the positive terminal of the diode D3, the diode D3 is conducted, the sum of the voltage at the B terminal of the PNP triode Q1 and the PN junction voltage of BE is smaller than the voltage at the power pin of the PWM control chip U1, the CE terminal of the PNP triode Q1 is conducted, the voltage at the power pin of the PWM control chip U1 is connected with the primary ground through the CE terminal of the PNP triode Q1 and the discharge resistor R2, the voltage at the power pin of the PWM control chip U1 is rapidly reduced to BE lower than the reset voltage of the PWM control chip U1, the PWM control chip U1 is reset, so that the switching power supply is rapidly reset after the power supply is powered off, after the AC input end is reconnected for a short time, the switching power supply can still normally output voltage, the experience of the customer is greatly improved.
To sum up, the utility model discloses after voltage conversion equipment disconnection alternating current input such as switching power supply, the voltage of PWM control chip U1's power pin department drops rapidly below PWM control chip U1's the reset voltage, and PWM control chip U1 resets, and when switching power supply inserts the alternating current again immediately after the disconnection alternating current like this, PWM control chip U1 can normally work, ensures that switching power supply can normal output voltage.
In light of the above, the present invention is not limited to the above embodiments, and various changes and modifications can be made by the worker without departing from the scope of the present invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.
Claims (5)
1. The utility model provides a quick reset circuit that is used for switching power supply after outage which characterized in that: the full-wave rectification circuit converts input alternating voltage into direct current voltage, when the full-wave rectification circuit inputs the alternating voltage, the full-wave rectification circuit charges the energy storage circuit, when the full-wave rectification circuit does not input the alternating voltage, the energy storage circuit discharges through the discharging circuit, the discharging voltage output end of the energy storage circuit is electrically connected with the negative electrode of the diode D3, the positive electrode of the diode D3 is electrically connected with the control end of the control switch, the input end of the control switch is electrically connected with a power pin of the PWM control chip, and the output end of the control switch is grounded.
2. The fast reset circuit for a switching power supply after power failure of claim 1, wherein: the control switch is a PNP triode Q1, and the collector of the PNP triode Q1 is grounded.
3. The fast reset circuit for a switching power supply after power failure of claim 1, wherein: the full-wave rectifying circuit comprises diodes D1 and D2, the anode of the diode D1 is electrically connected with the alternating current input end L, the cathode of the diode D1 is electrically connected with the alternating current input end N, and the cathodes of the diodes D1 and D2 are respectively electrically connected with the energy storage circuit and the discharge circuit.
4. The fast reset circuit for a switching power supply after power failure of claim 3, wherein: the energy storage circuit comprises an electrolytic capacitor EC1, the anode of the electrolytic capacitor EC1 is electrically connected with the cathode of the diode D1, the cathode of the diode D2 and the cathode of the diode D3 respectively, and the cathode of the electrolytic capacitor EC1 is grounded.
5. The fast reset circuit for a switching power supply after power failure of claim 4, wherein: the discharge circuit comprises a resistor R1, one end of the resistor R1 is electrically connected with the anode of the electrolytic capacitor EC1, and the other end of the resistor R1 is grounded.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120556627.0U CN214315082U (en) | 2021-03-17 | 2021-03-17 | Quick reset circuit used after power failure of switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120556627.0U CN214315082U (en) | 2021-03-17 | 2021-03-17 | Quick reset circuit used after power failure of switching power supply |
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| Publication Number | Publication Date |
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| CN214315082U true CN214315082U (en) | 2021-09-28 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202120556627.0U Active CN214315082U (en) | 2021-03-17 | 2021-03-17 | Quick reset circuit used after power failure of switching power supply |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117118418A (en) * | 2023-10-24 | 2023-11-24 | 成都爱旗科技有限公司 | Reset protection circuit |
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2021
- 2021-03-17 CN CN202120556627.0U patent/CN214315082U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117118418A (en) * | 2023-10-24 | 2023-11-24 | 成都爱旗科技有限公司 | Reset protection circuit |
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