TWI747521B - Power supply apparatus suppressing transient voltage - Google Patents

Abstract

A power supply apparatus suppressing a transient voltage is applied to an input voltage. The power supply apparatus includes a power supply circuit, a feedback signal generation circuit and a feedback signal control circuit. If the power supply circuit stops receiving the input voltage, the feedback signal control circuit controls the feedback signal generation circuit to discharge rendering that the feedback signal generation circuit controls the power supply circuit to decrease an output voltage, so that when the power supply circuit receives the input voltage again, the power supply circuit avoids generating an output overvoltage condition for the output voltage.

Description

Power supply device for suppressing transient voltage

The present invention relates to a power supply device, especially a power supply device that suppresses transient voltage.

A related art power supply circuit receives an input voltage to convert the input voltage into an output voltage; the related art power supply circuit can utilize a related art feedback signal generating circuit to feedback control the output voltage; usually, the The feedback signal generating circuit of the related technology may include an operational amplifier of the related technology and a reference voltage source of the related technology. The operational amplifier of the related technology is electrically connected to the reference voltage source of the related technology. The operational amplifier of the related technology A partial voltage of the output voltage is compared with a reference voltage of the reference voltage source of the related art to feedback control the output voltage; thereby, the power supply circuit of the related art can generate the stable output voltage.

If the power supply circuit of the related technology stops receiving the input voltage, the feedback signal generating circuit of the related technology will detect the decrease of the output voltage, so the feedback signal generating circuit of the related technology will control the related technology. The power supply circuit requires the power supply circuit of the related technology to increase the output voltage; if the operational amplifier of the related technology still works while the power supply circuit of the related technology stops receiving the input voltage, the power supply circuit of the related technology is required Increase the output voltage, when the power supply circuit of the related art receives the input voltage again, the output voltage Voltage will produce an output over-voltage condition, especially when the power supply circuit of the related art is in a light-load state or no-load state.

In order to solve the above-mentioned problems, the object of the present invention is to provide a power supply device that suppresses transient voltage.

In order to achieve the above object of the present invention, the power supply device for suppressing transient voltage of the present invention is applied to an input voltage. The power supply device for suppressing transient voltage includes: a power supply circuit; a feedback signal generating circuit, the A feedback signal generating circuit is electrically connected to the power supply circuit; and a feedback signal control circuit, the feedback signal control circuit is electrically connected to the power supply circuit and the feedback signal generating circuit, wherein if the power supply When the supply circuit stops receiving the input voltage, the feedback signal control circuit controls the feedback signal generation circuit to discharge so that the feedback signal generation circuit controls the power supply circuit to reduce an output voltage, so that when the power supply circuit restarts When receiving the input voltage, the power supply circuit avoids generating an output over-voltage condition for the output voltage.

Furthermore, in a specific embodiment of the power supply device for suppressing transient voltage of the present invention as described above, the power supply circuit includes: an auxiliary voltage generating sub-circuit, and the auxiliary voltage generating sub-circuit is electrically connected To the feedback signal control circuit.

Furthermore, in a specific embodiment of the power supply device for suppressing transient voltage of the present invention as described above, the feedback signal control circuit includes: a voltage detection sub-circuit, the voltage detection sub-circuit is an electrical It is connected to the auxiliary voltage generating sub-circuit.

Furthermore, in a specific embodiment of the power supply device for suppressing transient voltage of the present invention as described above, the feedback signal control circuit further includes: a voltage adjustment sub-circuit, the voltage adjustment sub-circuit is electrical Connected to the power supply circuit, the feedback signal generating circuit, and the voltage detection Measuring sub-circuit, wherein if the power supply circuit stops receiving the input voltage, the voltage detecting sub-circuit detects that the auxiliary voltage generating sub-circuit stops generating an auxiliary voltage and the voltage detecting sub-circuit notifies the voltage adjusting sub-circuit The auxiliary voltage generating sub-circuit stops generating the auxiliary voltage, so that the voltage adjusting sub-circuit controls the feedback signal generating circuit to discharge.

Furthermore, in a specific embodiment of the power supply device for suppressing transient voltage of the present invention as described above, the feedback signal generating circuit includes: a reference voltage source, the reference voltage source being electrically connected to the A voltage adjustment sub-circuit, wherein when the voltage adjustment sub-circuit controls the feedback signal generating circuit to discharge, the voltage adjustment sub-circuit outputs a low voltage to the reference voltage source, so that the reference voltage source stops working.

Furthermore, in a specific embodiment of the power supply device for suppressing transient voltage of the present invention as described above, the voltage detecting sub-circuit includes: a first sensing diode, the first sensing diode The pole system is electrically connected to the auxiliary voltage generating sub-circuit and the voltage adjusting sub-circuit; and a first resistor is electrically connected to the first auditing diode and the voltage adjusting sub-circuit.

Furthermore, in a specific embodiment of the power supply device for suppressing transient voltage of the present invention as described above, the voltage adjustment sub-circuit includes: a first diode, and the first diode system is electrically connected To the first audit diode and the first resistor; a second diode, the second diode system is electrically connected to the first diode and the reference voltage source; and a second resistor, The second resistor is electrically connected to the feedback signal generating circuit, the first diode and the second diode.

Furthermore, in a specific embodiment of the power supply device for suppressing transient voltage of the present invention as described above, the feedback signal generating circuit further includes: an operational amplifier, which is electrically connected to the reference Voltage source and the second resistor; and a feedback sub-circuit, the feedback sub-circuit is electrically connected to the operational amplifier and the power supply circuit, wherein the operational amplifier includes an operational amplifier output, an operational amplifier inverting Input terminal and a non-inverting input terminal of an operational amplifier; the The output terminal of the operational amplifier is electrically connected to the feedback sub-circuit; the non-inverting input terminal of the operational amplifier is electrically connected to the reference voltage source.

Furthermore, in a specific embodiment of the power supply device for suppressing transient voltage of the present invention as described above, the feedback signal generating circuit further includes: a first voltage dividing resistor, and the first voltage dividing resistor is Electrically connected to the power supply circuit, the second resistor, the inverting input terminal of the operational amplifier, and the feedback sub-circuit; and a second voltage dividing resistor, which is electrically connected to the first A voltage divider resistor and an inverting input terminal of the operational amplifier, wherein when the reference voltage source stops working, a first voltage of one of the non-inverting input terminals of the operational amplifier is less than the voltage between the first voltage dividing resistor and the second voltage divider A first voltage division between the resistors enables the operational amplifier to control the power supply circuit through the operational amplifier output terminal and the feedback sub-circuit to reduce the output voltage.

Furthermore, in a specific embodiment of the power supply device for suppressing transient voltage of the present invention as described above, the power supply circuit further includes: a pulse width modulation control sub-circuit, the pulse width modulation The control sub-circuit is electrically connected to the feedback sub-circuit; a power switch, the power-on relationship is electrically connected to the pulse width modulation control sub-circuit; a transformer, the transformer is electrically connected to the power switch and The auxiliary voltage generating sub-circuit; a rectifying and filtering circuit, the rectifying and filtering circuit is electrically connected to the transformer, the feedback sub-circuit, the first voltage dividing resistor and the second resistor; and an output terminal capacitor, the output The terminal capacitor is electrically connected to the first voltage divider resistor, the second resistor, the rectifying filter circuit, and the feedback sub-circuit.

The effect of the present invention is that if the feedback signal generating circuit is still working during the period when the power supply circuit stops receiving the input voltage, when the power supply circuit receives the input voltage again, the power supply circuit can avoid generating the output overvoltage situation. Furthermore, in an embodiment of the present invention, the effect of the present invention is that if the operational amplifier still works during the period when the power supply circuit stops receiving the input voltage, when the power supply circuit receives the input voltage again, the The power supply circuit can avoid the output over-voltage condition, especially when the power supply circuit is under light load. State or no-load state; wherein, if the operational amplifier is still working while the power supply circuit stops receiving the input voltage, the operational amplifier is forced to control the pulse width through the output terminal of the operational amplifier and the feedback sub-circuit The control sub-circuit is modulated to reduce the output voltage.

In order to have a better understanding of the technology, means and effects adopted by the present invention to achieve the intended purpose, please refer to the following detailed description and drawings of the present invention. I believe that the purpose, features and characteristics of the present invention can be obtained in depth and specificity. It is understood that, however, the accompanying drawings are only provided for reference and illustration, and are not intended to limit the present invention.

10: Power supply device to suppress transient voltage

20: Power supply circuit

30: Feedback signal generating circuit

40: Feedback signal control circuit

50: Input voltage

60: output voltage

202: Pulse width modulation control sub-circuit

204: Power switch

206: Transformer

208: rectifier filter circuit

210: auxiliary voltage generating sub-circuit

212: output capacitor

214: auxiliary voltage

302: Reference voltage source

306: Operational amplifier

308: Operational amplifier output

310: Op-amp inverting input

312: Operational amplifier non-inverting input

314: The first voltage divider resistor

316: Second voltage divider resistor

318: Feedback Sub-circuit

320: first voltage

322: First partial pressure

328: Reference voltage

402: Voltage detection sub-circuit

404: Voltage adjustment sub-circuit

406: low voltage

410: First Audit Diode

412: first resistance

414: first diode

416: second diode

420: second resistor

424: high voltage

FIG. 1 is a block diagram of the first embodiment of the power supply device for suppressing transient voltage of the present invention.

2 is a circuit block diagram of the second embodiment of the power supply device for suppressing transient voltage of the present invention.

In this disclosure, many specific details are provided to provide a thorough understanding of the specific embodiments of the present invention; however, those skilled in the art should know that in the absence of one or more of these specific details, The present invention can be practiced; in other cases, well-known details are not shown or described in order to avoid obscuring the main technical features of the present invention. The technical content and detailed description of the present invention are described as follows in conjunction with the drawings: Please refer to FIG. 1, which is a block diagram of the first specific embodiment of the power supply device for suppressing transient voltage of the present invention. A power supply device 10 for suppressing transient voltage of the present invention is applied to an input voltage 50; the power supply device 10 for suppressing transient voltage includes a power supply circuit 20, A feedback signal generating circuit 30 and a feedback signal control circuit 40; the above-mentioned components are electrically connected to each other. If the power supply circuit 20 stops receiving the input voltage 50, the feedback signal control circuit 40 controls the feedback signal generation circuit 30 to discharge so that the feedback signal generation circuit 30 controls the power supply circuit 20 to reduce an output The voltage 60 is such that when the power supply circuit 20 receives the input voltage 50 again, the power supply circuit 20 avoids an output over-voltage condition on the output voltage 60.

Furthermore, the input voltage 50 can be a DC voltage or an AC voltage. The power supply circuit 20 is used to convert the input voltage 50 into the output voltage 60; the power supply circuit 20 may be, for example, but the present invention is not limited to a power supply. The feedback signal generating circuit 30 is used to detect the output voltage 60 to control the power supply circuit 20 to feedback control the output voltage 60; the feedback signal generating circuit 30 may be, for example, but the present invention is not limited to one Grant signal generator. The feedback signal control circuit 40 can be, for example, but the present invention is not limited to a feedback signal controller. The above-mentioned power supply circuit 20 stopping receiving the input voltage 50 may be, for example, but the present invention is not limited to that the input voltage 50 is powered off.

Furthermore, the feedback signal control circuit 40 is used to detect an auxiliary voltage 214 provided by the power supply circuit 20; if the auxiliary voltage 214 exists (that is, the power supply circuit 20 receives the input voltage 50 The input voltage 50 is not powered off; the feedback signal control circuit 40 receives the auxiliary voltage 214), the feedback signal control circuit 40 generates and transmits a high voltage 424 to the feedback signal generation circuit 30 to make The feedback signal generating circuit 30 works normally (that is, the feedback signal generating circuit 30 detects the output voltage 60 to control the power supply circuit 20 to feedback control the output voltage 60); if the auxiliary voltage 214 Does not exist (that is, the power supply circuit 20 stops receiving the input voltage 50; the input voltage 50 is powered off; the feedback signal control circuit 40 stops receiving the auxiliary voltage 214), then the feedback signal control circuit 40 generates and A low voltage 406 is sent to the feedback signal generating circuit 30 so that the feedback signal generating circuit 30 can discharge to avoid requiring the power supply circuit 20 to increase the output voltage 60.

Please refer to FIG. 2, which is a circuit block diagram of the second embodiment of the power supply device for suppressing transient voltage of the present invention; the components shown in FIG. 2 are the same as those shown in FIG. 1, which is a concise factor. Therefore, the description will not be repeated here. The power supply circuit 20 includes a pulse width modulation control sub-circuit 202, a power switch 204, a transformer 206, a rectifier filter circuit 208, an auxiliary voltage generation sub-circuit 210 and an output capacitor 212; the feedback signal The generating circuit 30 includes a reference voltage source 302, the operational amplifier 306, a first voltage dividing resistor 314, a second voltage dividing resistor 316, and a feedback sub-circuit 318; the feedback signal control circuit 40 includes a voltage detection The sub-circuit 402 and a voltage adjustment sub-circuit 404; the operational amplifier 306 includes an operational amplifier output 308, an operational amplifier inverting input terminal 310 and an operational amplifier non-inverting input 312; the voltage detecting sub-circuit 402 includes A first audit diode 410 and a first resistor 412; the voltage adjustment sub-circuit 404 includes a first diode 414, a second diode 416, and a second resistor 420; the above-mentioned elements are mutually connected Electrical connection.

If the power supply circuit 20 stops receiving the input voltage 50, the voltage detecting sub-circuit 402 detects that the auxiliary voltage generating sub-circuit 210 stops generating the auxiliary voltage 214 and the voltage detecting sub-circuit 402 notifies the voltage regulator In circuit 404, the auxiliary voltage generating sub-circuit 210 stops generating the auxiliary voltage 214, so that the voltage adjusting sub-circuit 404 outputs the low voltage 406 to the reference voltage source 302, so that the reference voltage source 302 stops working and the operational amplifier is non-inverting. A first voltage 320 of the input terminal 312 is less than a first divided voltage 322 between the first voltage dividing resistor 314 and the second voltage dividing resistor 316, so that the operational amplifier 306 passes through the operational amplifier output terminal 308 and The feedback sub-circuit 318 controls the power supply circuit 20 to reduce the output voltage 60.

Wherein, if the power supply circuit 20 stops receiving the input voltage 50, then: an anode voltage of the first diode 414=[the output voltage 60×a first resistance value of the first resistor 412/(the first resistance) The first resistance value of a resistor 412 + a second resistance value of the second resistor 420)] + a first barrier voltage of the first diode 414

The low voltage 406=the anode voltage of the first diode 414 a second barrier voltage of the second diode 416=[the output voltage 60×the first resistance value of the first resistor 412/( The first resistance value of the first resistor 412 + the second resistance value of the second resistor 420)] + the first barrier voltage of the first diode 414-the first barrier voltage of the second diode 416 Second barrier voltage

If the first barrier voltage of the first diode 414 is equal to the second barrier voltage of the second diode 416 (for example, 0.7 volts), then: the low voltage 406=the output voltage 60×the first The first resistance value of the resistance 412/(the first resistance value of the first resistance 412 + the second resistance value of the second resistance 420)

Wherein, the reference voltage source 302 can be, for example, but the present invention is not limited to an audit diode, a step-down integrated circuit, a certain current source circuit or similar to include the first voltage divider resistor 314 and the second divider. A voltage divider circuit of the voltage divider circuit of the piezoresistor 316; the first resistance 412 and the second resistance 420 can be appropriately designed (for example, the first resistance value of the first resistance 412 is small), so that The low voltage 406 is sufficiently small that the reference voltage source 302 stops providing a reference voltage 328 to the non-inverting input terminal 312 of the operational amplifier (that is, the reference voltage source 302 mentioned above stops working). If the power supply circuit 20 stops receiving the input voltage 50, the aforementioned output voltage 60 is provided by the output capacitor 212 and gradually decreases.

Furthermore, if the power supply circuit 20 receives the input voltage 50, the voltage detecting sub-circuit 402 detects that the auxiliary voltage generating sub-circuit 210 generates the auxiliary voltage 214 and the voltage detecting sub-circuit 402 notifies the voltage The auxiliary voltage generating sub-circuit 404 generates the auxiliary voltage 214, so that the voltage adjusting sub-circuit 404 outputs the high voltage 424 to the reference voltage source 302, so that the reference voltage source 302 provides the reference voltage 328 to the calculation The non-inverting input terminal 312 of the amplifier enables the operational amplifier 306 to work normally.

Wherein, if the power supply circuit 20 receives the input voltage 50, then: A first cross voltage of the first resistor 412 = the auxiliary voltage 214-a second cross voltage of the first audit diode 410

The anode voltage of the first diode 414 = the first crossover voltage of the first resistor 412 + the first barrier voltage of the first diode 414 = the auxiliary voltage 214-the first sensing diode The second cross voltage of the body 410 + the first barrier voltage of the first diode 414

The high voltage 424 = the anode voltage of the first diode 414-the second barrier voltage of the second diode 416 = the auxiliary voltage 214-the second span of the first audit diode 410 Voltage + the first barrier voltage of the first diode 414-the second barrier voltage of the second diode 416

If the first barrier voltage of the first diode 414 is equal to the second barrier voltage of the second diode 416 (for example, 0.7 volts), then: the high voltage 424 = the auxiliary voltage 214-the first The second cross-pressure of the diode 410

For example, if the auxiliary voltage 214 is 10 volts, and if the second cross-voltage (ie, the breakdown voltage) of the first audit diode 410 is 7.5 volts, then the high voltage 424 is 2.5 volts; if the The reference voltage source 302 is a sensing diode, which has a breakdown voltage of 1.25 volts, and the aforementioned high voltage 424 (2.5 volts) transmitted to the reference voltage source 302 will cause the reference voltage source 302 to provide the reference voltage 328 (1.25 volts) to the non-inverting input terminal 312 of the operational amplifier, so that the operational amplifier 306 can work normally.

Furthermore, that the operational amplifier 306 can work normally means that if the first voltage 320 of the non-inverting input terminal 312 of the operational amplifier is smaller than the voltage between the first voltage dividing resistor 314 and the second voltage dividing resistor 316 Between the first divided voltage 322, the operational amplifier 306 controls the pulse width modulation control sub-circuit 202 through the operational amplifier output 308 and the feedback sub-circuit 318 to reduce the conduction of one of the power switches 204 If the first voltage 320 of the non-inverting input terminal 312 of the operational amplifier is greater than the first voltage divider between the first voltage divider resistor 314 and the second voltage divider 316 Voltage 322, the operational amplifier 306 controls the pulse width modulation control sub-circuit 202 through the operational amplifier output 308 and the feedback sub-circuit 318 to increase the conduction rate of the power switch 204 to increase the output voltage 60.

Furthermore, one end of the first audit diode 410 is connected to the auxiliary voltage generating sub-circuit 210, and the other end of the first audit diode 410 is connected to the voltage adjustment sub-circuit 404; the first One end of the resistor 412 is connected to the voltage adjustment sub-circuit 404 and the other end of the first audit diode 410, the other end of the first resistor 412 is connected to the ground; one end of the first diode 414 is Connected to the other end of the first audit diode 410 and one end of the first resistor 412; one end of the second diode 416 is connected to the other end of the first diode 414, the second second The other end of the pole body 416 is connected to the reference voltage source 302; one end of the second resistor 420 is connected to the feedback signal generating circuit 30, and the other end of the second resistor 420 is connected to the first diode The other end of 414 and one end of the second diode 416.

The effect of the present invention is that if the feedback signal generating circuit 30 still works while the power supply circuit 20 stops receiving the input voltage 50, when the power supply circuit 20 receives the input voltage 50 again, the power supply circuit 20 can Avoid this output over-voltage condition. Furthermore, in a specific embodiment of the present invention, the effect of the present invention is that if the operational amplifier 306 is still working while the power supply circuit 20 stops receiving the input voltage 50, when the power supply circuit 20 receives the input again When the voltage is 50, the power supply circuit 20 can avoid the output over-voltage condition, especially when the power supply circuit 20 is in a light-load state or no-load state; wherein, if the operational amplifier 306 is stopped in the power supply circuit 20 When receiving the input voltage 50 and still working, the operational amplifier 306 is forced to control the pulse width modulation control sub-circuit 202 through the operational amplifier output terminal 308 and the feedback sub-circuit 318 to reduce the output voltage 60.

However, the above are only preferred embodiments of the present invention, and should not limit the scope of implementation of the present invention, that is, all equivalent changes and modifications made in accordance with the claims of the present invention shall still belong to the present invention. The scope of patent coverage is intended to protect the scope. The present invention can also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications are all It should belong to the protection scope of the appended claims of the present invention. In summary, when it is known that the present invention has industrial applicability, novelty and advancement, and the structure of the present invention has not been seen in similar products and publicly used, it fully complies with the requirements of an invention patent application, and the application is filed in accordance with the Patent Law.

10: Power supply device to suppress transient voltage

20: Power supply circuit

30: Feedback signal generating circuit

40: Feedback signal control circuit

50: Input voltage

60: output voltage

214: auxiliary voltage

406: low voltage

424: high voltage

Claims (10)

A power supply device for suppressing transient voltage is applied to an input voltage. The power supply device for suppressing transient voltage includes: a power supply circuit; a feedback signal generating circuit, the feedback signal generating circuit is electrically connected To the power supply circuit; and a feedback signal control circuit, the feedback signal control circuit is electrically connected to the power supply circuit and the feedback signal generating circuit, wherein if the power supply circuit stops receiving the input voltage, then The feedback signal control circuit controls the feedback signal generation circuit to discharge so that the feedback signal generation circuit controls the power supply circuit to reduce an output voltage, so that when the power supply circuit receives the input voltage again, the power supply The circuit avoids generating an output over-voltage condition on the output voltage; wherein the feedback signal generating circuit includes: an operational amplifier, which is electrically connected to the feedback signal control circuit; and a feedback sub-circuit, the feedback signal The grant sub-circuit is electrically connected to the operational amplifier and the power supply circuit, wherein the power supply circuit includes: a pulse width modulation control sub-circuit, the pulse width modulation control sub-circuit is electrically connected to the back And a power switch, the power-on relationship is electrically connected to the pulse width modulation control sub-circuit, wherein the operational amplifier controls the pulse width modulation control sub-circuit through the feedback sub-circuit to reduce The conduction rate of one of the power switches reduces the output voltage. The power supply device for suppressing transient voltage according to claim 1, wherein the power supply circuit further comprises: an auxiliary voltage generating sub-circuit, and the auxiliary voltage generating sub-circuit is electrically connected to the feedback signal control circuit. The power supply device for suppressing transient voltage according to claim 2, wherein the feedback signal control circuit includes: a voltage detecting sub-circuit, and the voltage detecting sub-circuit is electrically connected to the auxiliary voltage generating sub-circuit. The power supply device for suppressing transient voltage according to claim 3, wherein the feedback signal control circuit further comprises: a voltage adjustment sub-circuit, the voltage adjustment sub-circuit is electrically connected to the power supply circuit and the feedback signal Signal generating circuit and the voltage detecting sub-circuit, wherein if the power supply circuit stops receiving the input voltage, the voltage detecting sub-circuit detects that the auxiliary voltage generating sub-circuit stops generating an auxiliary voltage and the voltage detecting sub-circuit The circuit informs the voltage adjusting sub-circuit that the auxiliary voltage generating sub-circuit stops generating the auxiliary voltage, so that the voltage adjusting sub-circuit controls the feedback signal generating circuit to discharge. The power supply device for suppressing transient voltage according to claim 4, wherein the feedback signal generating circuit further comprises: a reference voltage source, the reference voltage source is electrically connected to the voltage adjustment sub-circuit, wherein when the voltage When the adjusting sub-circuit controls the feedback signal generating circuit to discharge, the voltage adjusting sub-circuit outputs a low voltage to the reference voltage source, so that the reference voltage source stops working. The power supply device for suppressing transient voltage according to claim 5, wherein the voltage detecting sub-circuit includes: A first audit diode, the first audit diode system is electrically connected to the auxiliary voltage generation sub-circuit and the voltage adjustment sub-circuit; and a first resistor, the first resistor is electrically connected to the The first audit diode and the voltage adjustment sub-circuit. The power supply device for suppressing transient voltage according to claim 6, wherein the voltage adjustment sub-circuit includes: a first diode, the first diode system is electrically connected to the first audit diode and The first resistor; a second diode, the second diode system is electrically connected to the first diode and the reference voltage source; and a second resistor, the second resistor is electrically connected to the A feedback signal generating circuit, the first diode and the second diode. The power supply device for suppressing transient voltage according to claim 7, wherein the operational amplifier includes an operational amplifier output terminal, an operational amplifier inverting input terminal and an operational amplifier non-inverting input terminal; the operational amplifier output terminal is It is electrically connected to the feedback sub-circuit; the non-inverting input terminal of the operational amplifier is electrically connected to the reference voltage source. The power supply device for suppressing transient voltage according to claim 8, wherein the feedback signal generating circuit further comprises: a first voltage dividing resistor, and the first voltage dividing resistor is electrically connected to the power supply circuit and the A second resistor, the inverting input terminal of the operational amplifier, and the feedback sub-circuit; and a second voltage dividing resistor, which is electrically connected to the first voltage dividing resistor and the inverting input of the operational amplifier end, When the reference voltage source stops working, a first voltage of a non-inverting input terminal of the operational amplifier is less than a first voltage divided between the first voltage dividing resistor and the second voltage dividing resistor, so that the The operational amplifier controls the power supply circuit through the output terminal of the operational amplifier and the feedback sub-circuit to reduce the output voltage. The power supply device for suppressing transient voltage according to claim 9, wherein the power supply circuit further includes: a transformer electrically connected to the power switch and the auxiliary voltage generating sub-circuit; a rectifying and filtering circuit, The rectifying and filtering circuit is electrically connected to the transformer, the feedback sub-circuit, the first voltage divider resistor, and the second resistor; and an output terminal capacitor, which is electrically connected to the first voltage divider The resistor, the second resistor, the rectification filter circuit and the feedback sub-circuit.

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