CN212086544U - Input power control circuit and power when power output is short-circuited - Google Patents
Input power control circuit and power when power output is short-circuited Download PDFInfo
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- CN212086544U CN212086544U CN202020260314.6U CN202020260314U CN212086544U CN 212086544 U CN212086544 U CN 212086544U CN 202020260314 U CN202020260314 U CN 202020260314U CN 212086544 U CN212086544 U CN 212086544U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract
The utility model discloses an input power control circuit and a power supply when the power supply output is short-circuited, which comprises a power switch circuit, a transformer, an output rectifying and filtering circuit, a short circuit control circuit and a switch control circuit; the input end of the power switch circuit is connected with a power supply input, the output end of the power switch circuit is connected with the output rectifying and filtering circuit through a transformer, one path of the output end of the output rectifying and filtering circuit is connected with a load, the other path of the output end of the output rectifying and filtering circuit is connected with the switch control circuit through a short circuit control circuit, and the output end of the switch control circuit is connected with the power switch circuit; when the output of the output rectifying filter circuit is short-circuited, the short-circuit control circuit controls the power switch circuit to be disconnected through the switch control circuit so as to reduce the input power when the power supply outputs the short circuit. The utility model discloses input power when can reducing the power output short circuit to it is extravagant to reduce the energy, prevents that the power is out of control, improves the practicality and the reliability of power.
Description
Technical Field
The utility model relates to a drive power supply field especially relates to an input power control circuit and power when power output short circuit.
Background
The driving power supply is a power supply for converting external primary electric energy into secondary electric energy required by a load. The driving power supply can be applied to the fields of LED illumination, LED display screens, LED backlight and the like, wherein the LED illumination has the highest requirement on the driving control technology. The input power of the LED driving power source includes ac and dc, while the output power is generally a constant current that can vary in voltage as the forward voltage of the load varies. The stability of the quality of the driving power supply is a key factor of the service life of the LED lighting lamp.
However, the existing LED driving power supply technology has the following disadvantages:
in the LED driving power type with standby function or dimming turn-off function, an independent switching power supply B is generally built in the power supply a of the whole device to independently supply power to the chip of the main power supply a, the optocoupler and other IC semiconductors, so as to achieve the standby and dimming turn-off function after the power supply a is turned on. In the power supply of this topology, when the main power supply a is in an abnormal state of short-circuit output, the built-in independent power supply B still normally operates to supply power to the chip of the main power supply a, and in this case, the output short-circuit current of the main power supply a remains unchanged, but the output voltage is approximately zero. This would cause the input power of the main power supply a to be excessive in such abnormal situations, with the risk of energy waste and power supply a running away.
The defects are limited in use in the application field of the product, so that the practicability and the reliability of the product are reduced.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model is to provide an input power control circuit and power when power output short circuit.
The utility model provides a technical scheme that its technical problem adopted is: an input power control circuit when the power output is short-circuited is constructed, and the input power control circuit comprises a power switch circuit, a transformer, an output rectifying and filtering circuit, a short-circuit control circuit and a switch control circuit;
the input end of the power switch circuit is connected with a power supply input, the output end of the power switch circuit is connected with the output rectifying and filtering circuit through the transformer, one path of the output end of the output rectifying and filtering circuit is connected with a load, one path of the output end of the output rectifying and filtering circuit is connected with the switch control circuit through the short circuit control circuit, and the output end of the switch control circuit is connected with the power switch circuit;
when the output of the output rectifying and filtering circuit is short-circuited, the short-circuit control circuit controls the power switch circuit to be switched off through the switch control circuit so as to reduce the input power when the power supply is short-circuited.
Further, the utility model discloses an input power control circuit when power output is short-circuited, the switch control circuit includes feedback control circuit and the PWM control circuit who is connected with feedback control circuit;
the input end of the feedback control circuit is connected with the short-circuit control circuit; the output end of the PWM control circuit is connected with the power switch circuit;
the feedback control circuit transmits a feedback signal generated by the short-circuit control circuit to the PWM control circuit; and the PWM control circuit controls the power switch circuit to be switched on or switched off according to the feedback signal.
Furthermore, the input power control circuit for power output short circuit of the present invention comprises a first diode D1, a second diode D2, a first polar capacitor CE1, and a sampling resistor RS1,
the first diode D1 and the second diode D2 are connected in parallel, a connection point of an anode of the first diode D1 and an anode of the second diode D2 is connected with a positive output end of the secondary coil of the transformer, a connection point of a cathode of the first diode D1 and a cathode of the second diode D2 is respectively connected with the load input end and the anode of the first polar capacitor CE1, one path of a cathode of the first polar capacitor CE1 is connected with a negative output end of the secondary coil of the transformer, one path of a cathode of the first polar capacitor CE1 is connected with an analog ground, and one path of a cathode of the first polar capacitor CE1 is connected with the load output end through the sampling resistor RS 1;
and the output rectifying and filtering circuit rectifies and filters the alternating current voltage output by the secondary coil of the transformer into direct current voltage required by the load.
Furthermore, the input power control circuit for short circuit of power supply output of the present invention comprises a third diode D3, a sixth resistor R6, a seventh resistor R7, and a light emitter OT1-B of an optical coupler, wherein,
a light emitter OT1-B of the optocoupler is connected in parallel with the seventh resistor R7, one end of the sixth resistor R6 is connected with an auxiliary power output end VDD1, the other end of the sixth resistor R6 is connected with a connection point of an input end of the light emitter OT1-B and the seventh resistor R7, a cathode of the third diode D3 is connected with an anode of the first polar capacitor CE1, and an anode of the third diode D3 is connected with a connection point of an output end of the light emitter OT1-B and the seventh resistor R7;
when the output of the output rectifying and filtering circuit is short-circuited, the cathode of the third diode D3 is short-circuited with the analog ground to be at a low level, the anode of the third diode D3 is normally powered to be at a high level due to the auxiliary power output end VDD1, the third diode D3 is conducted, and the light emitter of the optical coupler is continuously conducted to emit light to output the feedback signal.
Furthermore, the power supply output short circuit time input power control circuit of the utility model also comprises a current control circuit and a voltage control circuit;
the input end of the current control circuit is connected with the output rectifying and filtering circuit, and the output end of the current control circuit is connected with the feedback control circuit; the input end of the voltage control circuit is connected with the output rectifying and filtering circuit, and the output end of the voltage control circuit is connected with the feedback control circuit;
the current control circuit is used for enabling the output rectifying and filtering circuit to output constant current; the voltage control circuit is used for enabling the output voltage of the output rectifying and filtering circuit to change along with the forward voltage of the load.
Furthermore, the input power control circuit for short circuit of power output of the present invention comprises an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a third capacitor C3, a fourth capacitor C4, a fifth diode D5, and a second comparator U1-B, wherein,
one end of the eleventh resistor R11 is connected with the reference current input end IREF, one end of the eleventh resistor R11 is connected with the analog ground through the thirteenth resistor R13, the non-inverting input terminal of the second comparator U1-B is connected to the series node of the eleventh resistor R11 and the thirteenth resistor R13 through the twelfth resistor R12, the inverting input terminal of the second comparator U1-B IS connected to the load output terminal IS + via the tenth resistor R10, the output end of the second comparator U1-B is connected with the cathode of the fifth diode D5 through the eighth resistor R8, the anode of the fifth diode D5 is connected with the short-circuit control circuit, the fourth capacitor C4 is connected between the inverting input terminal and the output terminal of the second comparator U1-B, the third capacitor C3 and the ninth resistor R9 are connected in series between the inverting input terminal and the output terminal of the second comparator U1-B.
Furthermore, the input power control circuit for short circuit of power supply output of the present invention comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a second capacitor C2, a fourth diode D4, and a first comparator U1-a,
one end of the first resistor R1 is connected to the load input VO +, the other end of the first resistor R1 is connected to an analog ground through the second resistor R2, the first capacitor C1 is connected in parallel to both ends of the first resistor R1, a non-inverting input end of the first comparator U1-A is connected to a reference voltage input VREF through the third resistor R3, an inverting input end of the first comparator U1-A is connected to a connection point of the first resistor R1 and the second resistor R2, the second capacitor C2 and the fourth resistor R4 are connected in series between the inverting input end and the output end of the first comparator U1-A, a power supply input end of the first comparator U1-A is connected to the auxiliary power output end VDD1, a ground of the first comparator U1-A is connected to the analog ground, and an output end of the first comparator U1-A is connected to a cathode of the fourth diode D4 through the fifth resistor R5, the anode of the fourth diode D4 is connected to the short circuit control circuit.
Furthermore, the input power control circuit for power output short circuit of the utility model also comprises a rectification filter circuit;
the input end of the rectification filter circuit receives alternating current input, and the output end of the rectification filter circuit is connected with the power switch circuit;
the rectification filter circuit converts the input alternating current into direct current to supply power to the power switch circuit.
Further, the input power control circuit for power output short circuit of the present invention further comprises an anti-interference circuit connected between the output end of the output rectifying and filtering circuit and the load;
the anti-jamming circuit comprises a second polar capacitor CE2 and a common-mode inductor LF1, wherein,
the first winding homonymy end of common mode inductance LF1 is connected the second has polarity electric capacity CE2 anodal, the first winding synonym end of common mode inductance LF1 is connected the load input end, common mode inductance LF1 second winding synonym end is connected the second has polarity electric capacity CE2 negative pole, common mode inductance LF1 second winding synonym end is connected the load output end.
The utility model discloses still construct a power, including above arbitrary power output short circuit time input power control circuit.
Implement the technical scheme of the utility model, following beneficial effect has: through increasing short circuit control circuit, when drive power supply output short circuit, short circuit control circuit produces feedback signal and gives the on-off control circuit, and then control power switch circuit disconnection to input power when reducing the power supply output short circuit, thereby reduce the energy extravagant, prevent that the power is out of control, improve the practicality and the reliability of power.
Drawings
The invention will be further explained with reference to the drawings and examples, wherein:
fig. 1 is a schematic structural diagram of a first embodiment of the present invention;
fig. 2 is a schematic structural diagram of a second embodiment of the present invention;
fig. 3 is a schematic diagram of a part of main circuits of the second embodiment of the present invention.
Detailed Description
In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
As shown in fig. 1, the present invention provides a power output short-circuit input power control circuit, which comprises a power switch circuit 10, a transformer 20, an output rectifying and filtering circuit 30, a short-circuit control circuit 40, and a switch control circuit 50;
the input end of the power switch circuit 10 is connected with a power supply input, the output end of the power switch circuit 10 is connected with the output rectifying and filtering circuit 30 through the transformer 20, one path of the output end of the output rectifying and filtering circuit 30 is connected with a load, one path of the output end of the output rectifying and filtering circuit 30 is connected with the switch control circuit 50 through the short circuit control circuit 40, and the output end of the switch control circuit 50 is connected with the power switch circuit 10;
when the output of the output rectifying and filtering circuit 30 is short-circuited, the short-circuit control circuit 40 controls the power switch circuit 10 to be switched off through the switch control circuit 50, so as to reduce the input power when the power supply output is short-circuited.
Specifically, the control circuit works in the following way: when the output of the output rectifying and filtering circuit 30 is short-circuited, for example, the load is short-circuited, the output voltage is approximately zero, but since the independent auxiliary power supply built in the power supply still supplies power normally, the output short-circuit current remains unchanged, and at this time, the short-circuit control circuit 40 generates a feedback signal to control the switch circuit 10 to be turned off, so that the transformer 20 stops working, and the transformer 20 has no current output, so as to reduce the input power when the power supply is short-circuited.
The above working mode can stop the power supply circuit through the short circuit control circuit 40 when the power supply output is short-circuited, and reduce the input power, thereby reducing the energy waste and preventing the power supply from being out of control.
Referring to fig. 2, the input power control circuit for short circuit of power supply output in the present embodiment is based on the first embodiment, and further, the switch control circuit 50 includes a feedback control circuit 501 and a PWM control circuit 502 connected to the feedback control circuit 501;
the input end of the feedback control circuit 501 is connected with the short-circuit control circuit 40; the output end of the PWM control circuit 502 is connected to the power switch circuit 10;
the feedback control circuit 501 transmits a feedback signal generated by the short-circuit control circuit 40 to the PWM control circuit 502; the PWM control circuit 502 controls the power switching circuit 10 to be turned on or off according to the feedback signal.
It can be understood that feedback control circuit 501 can be opto-coupler feedback control circuit, PWM control circuit 502 is PWM chip control circuit, feedback control circuit 501 transmits the feedback signal that short circuit control circuit 40 produced to PWM control circuit 502's PWM chip through the photic ware of opto-coupler promptly, with this output pulse width who adjusts the PWM chip, and then make power switch circuit 10 disconnection, make transformer 20 stop work no current output, and then reduce the input power of power, thereby it is extravagant to reduce the energy, prevent that the power is out of control, improve power reliability and stability.
Further, a current control circuit 60 and a voltage control circuit 70 are also included; the input end of the current control circuit 60 is connected with the output rectifying and filtering circuit 30, and the output end of the current control circuit 60 is connected with the feedback control circuit 501; the input end of the voltage control circuit 70 is connected with the output rectifying and filtering circuit 30, and the output end of the voltage control circuit 70 is connected with the feedback control circuit 501;
the current control circuit 60 is configured to cause the output rectifying and filtering circuit 30 to output a constant current; the voltage control circuit 70 is used to make the output voltage of the output rectifying and filtering circuit 30 vary with the forward voltage of the load.
Further, a rectifying and filtering circuit 80 is also included; the input end of the rectification filter circuit 80 receives alternating current input, and the output end of the rectification filter circuit 80 is connected with the power switch circuit 10;
the rectifying and filtering circuit 80 converts the input ac power into dc power to power the power switching circuit 10.
Further, the circuit also comprises an anti-jamming circuit 90 connected between the output end of the output rectifying and filtering circuit 30 and the load; the anti-jamming circuit 90 has the effects of lightning stroke resistance and electromagnetic interference resistance, and the reliability and stability of the power supply are further improved.
Referring to fig. 3, the output rectifying-filtering circuit 30 of the present embodiment includes a first diode D1, a second diode D2, a first polar capacitor CE1, and a sampling resistor RS1, wherein,
a first diode D1 and a second diode D2 are connected in parallel, the connection point of the anode of the first diode D1 and the anode of the second diode D2 is connected with the positive output end of the secondary coil of the transformer 20, the connection point of the cathode of the first diode D1 and the cathode of the second diode D2 is respectively connected with the load input end and the anode of a first polar capacitor CE1, one path of the cathode of the first polar capacitor CE1 is connected with the negative output end of the secondary coil of the transformer, one path of the cathode of the first polar capacitor CE1 is connected with an analog ground, and one path of the cathode of the first polar capacitor CE1 is connected with the load output end through a sampling resistor RS 1;
the output rectifying and filtering circuit 30 rectifies and filters the ac voltage output from the secondary winding of the transformer 20 into a dc voltage required by the load.
The short circuit control circuit 40 includes a third diode D3, a sixth resistor R6, a seventh resistor R7, and a light emitter OT1-B of the photo-coupler, wherein,
a light emitter OT1-B of the optical coupler is connected with a seventh resistor R7 in parallel, one end of a sixth resistor R6 is connected with an auxiliary power output end VDD1, the other end of the sixth resistor R6 is connected with a connection point of an input end of the light emitter OT1-B and the seventh resistor R7, a cathode of a third diode D3 is connected with an anode of a first polar capacitor CE1, and an anode of a third diode D3 is connected with a connection point of an output end of the light emitter OT1-B and the seventh resistor R7;
when the output of the output rectifying and filtering circuit 30 is short-circuited, the cathode of the third diode D3 is short-circuited to the analog ground to be at a low level, the anode of the third diode D3 is normally powered to be at a high level due to the auxiliary power output terminal VDD1, the third diode D3 is turned on, and the light emitter of the optical coupler is continuously turned on to emit a light output feedback signal.
The specific operation principle of the input power control circuit during power output short circuit according to the present invention is described in detail below with reference to fig. 3:
when the output is normally established, the voltage at the output end of the power supply, i.e. the output end VO + of the rectifying and filtering circuit 30, is much higher than the voltage at the point B, the third diode D3 is turned off in the reverse direction, when the output end is short-circuited, for example, when the load is short-circuited or the output end is short-circuited, the voltage at the point VO + is short-circuited to the analog ground and is at a low level, but the auxiliary power supply AUX still works normally, the voltage at the output end VDD1 is stable and does not change, so that the voltage at the point B is at a high level, the third diode D3 is turned on in the forward direction because the anode voltage is greater than the cathode voltage, then the auxiliary power supply AUX current forms a loop through the resistor R6, the opto-coupled light emitter OT1-B, the diode D2 and the analog ground AGND, the light emitter OT1-B of the opto-coupler is continuously turned on to emit light, and then outputs a feedback signal, and the, further, the power switching circuit 10 is controlled to be turned off, and the transformer 20 stops operating and no current is output, so that the input power of the power supply is reduced until the short-circuit state is released and the third diode D3 returns to the reverse blocking state. It is understood that the short-circuit releasing state can be the manual replacement of a short-circuited load such as a short-circuited LED lamp or a fuse, and the third diode D3 can restore the reverse blocking state.
The current control circuit 60 includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a third capacitor C3, a fourth capacitor C4, a fifth diode D5, and a second comparator U1-B,
one end of an eleventh resistor R11 IS connected with the reference current input end IREF, one end of an eleventh resistor R11 IS connected with the analog ground through a thirteenth resistor R13, the non-inverting input end of a second comparator U1-B IS connected with the series node of the eleventh resistor R11 and the thirteenth resistor R13 through a twelfth resistor R12, the inverting input end of the second comparator U1-B IS connected with the load output end IS + through the tenth resistor R10, the output end of the second comparator U1-B IS connected with the cathode of a fifth diode D5 through an eighth resistor R8, the anode of the fifth diode D5 IS connected with the connection point of the output end of a light emitter OT1-B and a seventh resistor R7, a fourth capacitor C4 IS connected between the inverting input end and the output end of the second comparator U1-B, and a third capacitor C3 and a ninth resistor R9 are connected in series between the inverting input end and the output end of the second comparator U1-B.
It can be understood that the current control circuit 60 samples the current flowing through the load, converts the sampled current into a voltage to be compared with a reference voltage, and then outputs a control signal, and controls the output pulse width of the PWM control circuit 502 through the opto-coupler light emitter OT1-B and the feedback control circuit 501, so as to adjust the output current of the transformer 20, and thus make the output current constant.
The voltage control circuit 70 comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a second capacitor C2, a fourth diode D4, and a first comparator U1-a, wherein,
one end of a first resistor R1 is connected with a load input end VO +, the other end of the first resistor R1 is connected with an analog ground through a second resistor R2, a first capacitor C1 is connected with two ends of the first resistor R1 in parallel, a non-inverting input end of a first comparator U1-A is connected with a reference voltage input end VREF through a third resistor R3, an inverting input end of the first comparator U1-A is connected with a connection point of a first resistor R1 and a second resistor R2, a second capacitor C2 and a fourth resistor R4 are connected between an inverting input end and an output end of the first comparator U1-A in series, a power supply input end of the first comparator U1-A is connected with an auxiliary power supply output end 37VDD, a ground of the first comparator U1-A is connected with the analog ground, an output end of the first comparator U1-A is connected with a cathode of a fourth diode D4 through a fifth resistor R5, and a fourth diode D4 is connected with an anode light emitter 58OT 23-B output end and a connection point 7.
It can be understood that the voltage control circuit 70 samples the voltage of the load, compares the sampled voltage with a reference voltage, and then outputs a control signal, and controls the output pulse width of the PWM control circuit 502 through the opto-coupler light emitter OT1-B and the feedback control circuit 501, so as to adjust the output voltage of the transformer 20, so that the voltage output by the power supply changes with the change of the forward voltage of the load.
The immunity circuit 90 includes a second polar capacitor CE2, a common mode inductor LF1, wherein,
the dotted terminal of the first winding of the common-mode inductor LF1 is connected with the positive electrode of the second polar capacitor CE2, the dotted terminal of the first winding of the common-mode inductor LF1 is connected with the load input terminal, the dotted terminal of the second winding of the common-mode inductor LF1 is connected with the negative electrode of the second polar capacitor CE2, and the dotted terminal of the second winding of the common-mode inductor LF1 is connected with the load output terminal.
The anti-jamming circuit 90 has the effects of lightning stroke resistance and external electromagnetic interference resistance, and the reliability and the stability of the circuit are further improved.
Additionally, the utility model also provides a power, input power control circuit when including the power output short circuit of above arbitrary description. The power supply can be applied to the fields of LED illumination, LED display screens, LED backlight and the like. Specifically, through setting up this control circuit in that the power is inside, can be when power output end short circuit, in time control power stop work avoids power input power too high, reduces the energy loss, prevents that the power is out of control, improves power reliability and stability.
It is to be understood that the foregoing examples merely represent preferred embodiments of the present invention, and that the description thereof is more specific and detailed, but not intended to limit the scope of the invention; it should be noted that, for those skilled in the art, the above technical features can be freely combined, and several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention; therefore, all changes and modifications that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
Claims (10)
1. An input power control circuit when power supply output is short-circuited is characterized by comprising a power switch circuit (10), a transformer (20), an output rectifying and filtering circuit (30), a short-circuit control circuit (40) and a switch control circuit (50);
the input end of the power switch circuit (10) is connected with a power supply input, the output end of the power switch circuit (10) is connected with the output rectifying and filtering circuit (30) through the transformer (20), one path of the output end of the output rectifying and filtering circuit (30) is connected with a load, one path of the output end of the output rectifying and filtering circuit (30) is connected with the switch control circuit (50) through the short circuit control circuit (40), and the output end of the switch control circuit (50) is connected with the power switch circuit (10);
when the output of the output rectifying and filtering circuit (30) is short-circuited, the short-circuit control circuit (40) controls the power switch circuit (10) to be switched off through the switch control circuit (50) so as to reduce the input power when the power output is short-circuited.
2. The input power control circuit when the power supply output is short-circuited according to claim 1, wherein the switch control circuit (50) comprises a feedback control circuit (501) and a PWM control circuit (502) connected to the feedback control circuit (501);
the input end of the feedback control circuit (501) is connected with the short-circuit control circuit (40); the output end of the PWM control circuit (502) is connected with the power switch circuit (10);
the feedback control circuit (501) transmits a feedback signal generated by the short circuit control circuit (40) to the PWM control circuit (502); the PWM control circuit (502) controls the power switch circuit (10) to be switched on or switched off according to the feedback signal.
3. The input power control circuit when the power supply output is short-circuited according to claim 2, wherein the output rectifying filter circuit (30) comprises a first diode D1, a second diode D2, a first polar capacitor CE1, and a sampling resistor RS1,
the first diode D1 and the second diode D2 are connected in parallel, a connection point of an anode of the first diode D1 and an anode of the second diode D2 is connected with a positive output end of a secondary coil of the transformer (20), a connection point of a cathode of the first diode D1 and a cathode of the second diode D2 is respectively connected with the load input end and an anode of the first polar capacitor CE1, one path of a cathode of the first polar capacitor CE1 is connected with a negative output end of the secondary coil of the transformer, one path of a cathode of the first polar capacitor CE1 is connected with an analog ground, and one path of a cathode of the first polar capacitor CE1 is connected with the load output end through the sampling resistor RS 1;
the output rectifying and filtering circuit (30) rectifies and filters the alternating current voltage output by the secondary coil of the transformer (20) into direct current voltage required by the load.
4. The input power control circuit when power supply output is short-circuited according to claim 3, wherein the short circuit control circuit (40) comprises a third diode D3, a sixth resistor R6, a seventh resistor R7, a light emitter OT1-B of an optocoupler, wherein,
a light emitter OT1-B of the optocoupler is connected in parallel with the seventh resistor R7, one end of the sixth resistor R6 is connected with an auxiliary power output end VDD1, the other end of the sixth resistor R6 is connected with a connection point of an input end of the light emitter OT1-B and the seventh resistor R7, a cathode of the third diode D3 is connected with an anode of the first polar capacitor CE1, and an anode of the third diode D3 is connected with a connection point of an output end of the light emitter OT1-B and the seventh resistor R7;
when the output of the output rectifying and filtering circuit (30) is short-circuited, the cathode of the third diode D3 is short-circuited with the analog ground to be at a low level, the anode of the third diode D3 is at a high level due to the normal power supply of the auxiliary power output end VDD1, the third diode D3 is conducted, and the light emitter of the optical coupler is continuously conducted to emit light to output the feedback signal.
5. The input power control circuit when the power supply output is short-circuited according to claim 2, further comprising a current control circuit (60) and a voltage control circuit (70);
the input end of the current control circuit (60) is connected with the output rectifying and filtering circuit (30), and the output end of the current control circuit (60) is connected with the feedback control circuit (501); the input end of the voltage control circuit (70) is connected with the output rectifying and filtering circuit (30), and the output end of the voltage control circuit (70) is connected with the feedback control circuit (501);
the current control circuit (60) is used for enabling the output rectifying and filtering circuit (30) to output constant current; the voltage control circuit (70) is used for enabling the output voltage of the output rectifying and filtering circuit (30) to change along with the forward voltage of the load.
6. The input power control circuit when the power supply output is short-circuited according to claim 5, wherein the current control circuit (60) comprises an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a third capacitor C3, a fourth capacitor C4, a fifth diode D5, and a second comparator U1-B,
one end of the eleventh resistor R11 is connected with the reference current input end IREF, one end of the eleventh resistor R11 is connected with the analog ground through the thirteenth resistor R13, the non-inverting input terminal of the second comparator U1-B is connected to the series node of the eleventh resistor R11 and the thirteenth resistor R13 through the twelfth resistor R12, the inverting input terminal of the second comparator U1-B IS connected to the load output terminal IS + via the tenth resistor R10, the output end of the second comparator U1-B is connected with the cathode of the fifth diode D5 through the eighth resistor R8, the anode of the fifth diode D5 is connected with the short-circuit control circuit (40), the fourth capacitor C4 is connected between the inverting input end and the output end of the second comparator U1-B, the third capacitor C3 and the ninth resistor R9 are connected in series between the inverting input terminal and the output terminal of the second comparator U1-B.
7. The input power control circuit when the power supply output is short-circuited according to claim 5, wherein the voltage control circuit (70) comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a second capacitor C2, a fourth diode D4, and a first comparator U1-A,
one end of the first resistor R1 is connected to the load input VO +, the other end of the first resistor R1 is connected to an analog ground through the second resistor R2, the first capacitor C1 is connected in parallel to both ends of the first resistor R1, a non-inverting input end of the first comparator U1-A is connected to a reference voltage input VREF through the third resistor R3, an inverting input end of the first comparator U1-A is connected to a connection point of the first resistor R1 and the second resistor R2, the second capacitor C2 and the fourth resistor R4 are connected in series between the inverting input end and the output end of the first comparator U1-A, a power supply input end of the first comparator U1-A is connected to the auxiliary power output end VDD1, a ground of the first comparator U1-A is connected to the analog ground, and an output end of the first comparator U1-A is connected to a cathode of the fourth diode D4 through the fifth resistor R5, the anode of the fourth diode D4 is connected to the short circuit control circuit (40).
8. The input power control circuit when the power supply output is short-circuited according to claim 1, further comprising a rectifying-filtering circuit (80);
the input end of the rectification filter circuit (80) receives alternating current input, and the output end of the rectification filter circuit (80) is connected with the power switch circuit (10);
the rectification filter circuit (80) converts the input alternating current into direct current to supply power to the power switch circuit (10).
9. The input power control circuit when the power supply output is short-circuited according to claim 1, further comprising an anti-jamming circuit (90) connected between the output of the output rectifying and filtering circuit (30) and the load;
the anti-jamming circuit (90) comprises a second polar capacitor CE2 and a common-mode inductor LF1, wherein,
the first winding homonymy end of common mode inductance LF1 is connected the second has polarity electric capacity CE2 anodal, the first winding synonym end of common mode inductance LF1 is connected the load input end, common mode inductance LF1 second winding synonym end is connected the second has polarity electric capacity CE2 negative pole, common mode inductance LF1 second winding synonym end is connected the load output end.
10. A power supply comprising the power supply output short circuit input power control circuit of any one of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020260314.6U CN212086544U (en) | 2020-03-05 | 2020-03-05 | Input power control circuit and power when power output is short-circuited |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020260314.6U CN212086544U (en) | 2020-03-05 | 2020-03-05 | Input power control circuit and power when power output is short-circuited |
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| Publication Number | Publication Date |
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| CN212086544U true CN212086544U (en) | 2020-12-04 |
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| CN202020260314.6U Active CN212086544U (en) | 2020-03-05 | 2020-03-05 | Input power control circuit and power when power output is short-circuited |
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