CN110492442B - ACDC switching power supply protection circuit and protection method - Google Patents
ACDC switching power supply protection circuit and protection method Download PDFInfo
- Publication number
- CN110492442B CN110492442B CN201910675361.9A CN201910675361A CN110492442B CN 110492442 B CN110492442 B CN 110492442B CN 201910675361 A CN201910675361 A CN 201910675361A CN 110492442 B CN110492442 B CN 110492442B
- Authority
- CN
- China
- Prior art keywords
- power supply
- resistor
- capacitor
- switching power
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 102100031786 Adiponectin Human genes 0.000 title claims abstract description 27
- 101000775469 Homo sapiens Adiponectin Proteins 0.000 title claims abstract description 27
- 238000000034 method Methods 0.000 title claims abstract description 24
- 239000003990 capacitor Substances 0.000 claims description 134
- 230000003287 optical effect Effects 0.000 description 5
- 238000004891 communication Methods 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000002159 abnormal effect Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 208000031361 Hiccup Diseases 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/125—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for rectifiers
- H02H7/1252—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for rectifiers responsive to overvoltage in input or output, e.g. by load dump
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/125—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for rectifiers
- H02H7/1257—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for rectifiers responsive to short circuit or wrong polarity in output circuit
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention discloses an ACDC switching power supply protection circuit and a protection method, wherein the method comprises the following steps: the input end of the rectifying circuit is connected with an alternating current input voltage, the output end of the rectifying circuit is respectively connected with the input end of the current-limiting resistance circuit and the primary side of the transformer, and the output end of the current-limiting resistance circuit is connected to the power input end of the switching power supply circuit; the input end of the transformer feedback power supply circuit is connected with the secondary side of the transformer, and the output end of the transformer feedback power supply circuit is connected with the power supply input end of the switch power supply circuit through the current-limiting resistor; the input of the optocoupler feedback circuit is connected with the other secondary side of the transformer, and the output end of the power supply protection circuit is connected to the output feedback end of the switching power supply circuit. The invention effectively protects the switching power supply by raising the voltage of the output feedback end of the switching power supply, and has the advantages of simple design, low cost, good reliability and strong applicability.
Description
Technical Field
The invention relates to the field of switching power supplies, in particular to an ACDC switching power supply protection circuit and a protection method.
Background
The switching power supply is widely applied to military and civil electronic systems such as aviation, ships, weapons, railways, communication, medical electronics, industrial automation equipment and the like in the industrial and national defense fields, when the switching power supply is overloaded or short-circuited in the use or debugging process, a protection circuit is indispensable, the protection circuit can greatly reduce the damage to the switching power supply, and the normal operation and personal safety of machine equipment are ensured.
The existing control chip of the switching power supply is lack of an overvoltage protection circuit, if a power supply feedback loop is damaged or feedback loss is caused by insufficient soldering, the output voltage of the secondary side of the whole transformer is increased, and therefore a subsequent load circuit is damaged due to overvoltage or serious heating. In order to solve the problem, a feedback circuit is separately added for overvoltage protection, so that the cost is higher.
Disclosure of Invention
In order to solve at least one technical problem, the invention provides an ACDC switching power supply protection circuit and a protection method.
In order to solve the above technical problem, a first aspect of the present invention discloses an ACDC switching power supply protection circuit, including: the transformer feedback power supply circuit comprises a rectifying circuit, a current-limiting resistance circuit, a switching power supply circuit, a transformer feedback power supply circuit, an optocoupler feedback circuit and a power supply protection circuit, wherein the input end of the rectifying circuit is connected with an alternating current input voltage, the output end of the rectifying circuit is respectively connected with the input end of the current-limiting resistance circuit and the primary side of the transformer, and the output end of the current-limiting resistance circuit is connected to the power supply input end of the switching power supply circuit; the input end of the transformer feedback power supply circuit is connected with the secondary side of the transformer, and the output end of the transformer feedback power supply circuit is connected with the power supply input end of the switch power supply circuit through the current-limiting resistor; the input of the optocoupler feedback circuit is connected with the other secondary side of the transformer, the output end of the optocoupler feedback circuit is respectively connected to the current compensation control end of the switching power supply circuit and the input end of the power supply protection circuit, and the output end of the power supply protection circuit is connected to the output feedback end of the switching power supply circuit.
In the scheme, the rectifier circuit comprises a rectifier bridge D1, a capacitor EC1, a capacitor EC2, a resistor R3 and a resistor R11, and the specific connection relationship is that alternating-current input voltage is respectively connected to a second connection end, a third connection end and a fourth connection end of the rectifier bridge D1, a 1 st connection end of the rectifier bridge D1 is respectively connected to one end of the capacitor EC1, one end of the resistor R3 and an input end of a current-limiting resistor circuit, a 1 st connection end of the rectifier bridge D1 is further connected to a 17 th connection end of a transformer, the other end of the capacitor EC1 is respectively connected with one end of the capacitor EC2, one end of the resistor R11 and the other end of the resistor R3, and a fifth connection end of the rectifier bridge D1, the other end of the capacitor EC2 and the other end of the resistor R11 are all grounded.
In this aspect, the current limiting resistor circuit includes: the resistors R1, R6, R10, R9, R5, R4 and R8 have the following specific connection relations: the resistors R1, R6, R10, R9, R5, R4 and R8 are sequentially connected in series, and the input end of the resistor R1 is connected with the output end of the rectifying circuit.
In this scheme, switching power supply circuit includes: the switching power supply chip U1, the power MOS tube Q1, the resistors R2, R7, R14, R15, R16, R18, R19, R20 and R21 have capacitors C1C 2C 3C 5C 7C 6C 9, capacitors EC4 and EC5 and diodes DZ1, DZ2, D2 and D5, and the specific connection relations are as follows: the output end of the rectifier bridge is respectively connected to one end of a R2, one end of a capacitor C1, one end of a capacitor C2, one end of a capacitor C3, the anode of a diode DZ2, the other end of a capacitor C1C 2 is connected with VDC-, the other end of a resistor R2 is connected to one end of the R7, the other end of a resistor R7, the other end of the capacitor C3 and the cathode of a diode DZ2 are connected to the cathode of the diode D2, and the anode of a diode D2 is connected to the 21 st connecting end of the transformer and the D electrode of a power MOS transistor Q1;
a pin 7 of the switching power supply chip U1 is respectively connected to one end of a capacitor C5, one end of a capacitor EC4 and the cathode of a diode DZ1, a pin 5 of the switching power supply chip U1 is respectively connected to the other end of a capacitor C5, the other end of a capacitor EC4, the anode of a diode DZ1, one end of a capacitor C7 and one end of a capacitor EC5, the other end of the capacitor C7 is respectively connected to a pin 4 of the switching power supply chip U1, one end of a resistor R21, the other end of a capacitor EC5 and the other end of a resistor R21 are connected to an 8 pin of a switching power supply chip U1, a 6 pin of the switching power supply chip U1 is connected to one end of a resistor R15 and the cathode of a diode D5 respectively, the anode of a diode D5 is connected to one end of the resistor R14, the other end of a resistor R15 and the other end of the resistor R14 are connected to the G pole of a power MOS transistor Q1, one end of the resistor R16 and one end of a capacitor C6, and the other end of the resistor R16 and the other end of the capacitor C6 are connected to a VDC-connection end;
the 3 pins of the switching power supply chip U1 are connected to one end of a capacitor C9 and one end of a resistor R18 respectively, the other end of the capacitor C9 is connected to a VDC-connection end, the other end of the resistor R18 is connected to one end of a resistor R19, the S pole of a power MOS transistor Q1 and one end of a resistor R20, and the other end of the resistor R19 and the other end of the resistor R20 are connected to the VDC-connection end.
In this scheme, transformer feedback power supply circuit includes: the resistor R12, the diodes D3 and D4, the resistor R13, the capacitor EC3 and the capacitor C4 have the following specific connection relations: the anode of the diode D4 is connected to the 28 th connection end of the transformer, the cathode of the diode D4 is respectively connected to one end of a resistor R13, one end of a capacitor C4, one end of a capacitor EC3 and the anode of a diode D3, and the other ends of the resistor R13, the capacitor C4 and the capacitor EC3 are connected to the 27 th connection end and the VDC-connection end of the transformer;
the cathode of the diode D3 is connected to one end of the resistor R12, and the other end of the resistor R12 is connected to the 7 pin of the switching power supply chip U1.
In this scheme, opto-coupler feedback circuit includes: the photoelectric coupler U2, the reference power chip U3, resistance R17, R23, R24, R25, R28, R30, electric capacity C8, C10, C11, electric capacity EC6, diode D6, the specific relation of connection is: a pin 1 of the switching power supply chip U1 is connected to a pin 4 of the photocoupler U2, a pin 1 of the photocoupler U2 is connected to one end of a resistor R23, the other end of the resistor R23 is respectively connected to one end of a resistor R24, one end of a resistor R25, one end of a capacitor EC6, one end of a capacitor C10, one end of a capacitor C8 and the cathode of a diode D6, the anode of the diode D6 is connected to the 32 th connection end of the transformer, the other end of the capacitor C8 is connected to one end of a resistor R17, and the other end of the resistor R17 is connected to the 32 th connection end of the transformer; a pin 2 of the photocoupler U2 is connected to the other end of the resistor R24, one end of the resistor R28, a pin 3 of the power reference chip U3, the other end of the resistor R28 is connected to one end of the capacitor C11, the other end of the capacitor C11 and the other end of the resistor R25 are both connected to one end of the resistor R30, a pin 1 of the power reference chip U3 is also connected to one end of the resistor R30, and a pin 2 of the power reference chip U3, the other end of the resistor R30, the other end of the capacitor EC6 and the other end of the capacitor C10 are both connected to the 31 th connection end of the transformer and the ground.
In this scheme, the power protection circuit includes: triode Q2, resistance R22, R26, R27, R29, electric capacity C12, the concrete relation of connection is: the 8 pin of the switching power supply chip U1 is connected to one end of a resistor R22, the other end of the resistor R22 is connected to one end of a resistor R26 and the 2 pin of the switching power supply chip U1 respectively, the other end of the resistor R26 is connected to one end of a capacitor C12, the other end of the capacitor C12 is connected to a VDC-connection end and the emitter of a triode Q2 respectively, the collector of a triode Q2 is connected to the 2 pin of the switching power supply chip U1, the emitter of a triode Q2 is connected to one end of the resistor R29, the base of a triode Q2 is connected to one end of a resistor R27, and the other end of the resistor R29 and the other end of the resistor R29 are connected to the 3 pin of a photocoupler U2.
In the scheme, the switching power supply chip is a UCX84X chip.
A second aspect of the present invention provides an ACDC switching power supply protection method, for use in an ACDC switching power supply protection circuit as described in any one of the above, the method including:
when the output of the switching power supply is lost or short-circuited, a photoelectric coupler in the photoelectric coupler feedback circuit is in a non-conductive state, a voltage feedback pin of a chip of the switching power supply is increased to a preset voltage value, and the switching power supply stops working;
the restarting time of the switching power supply is controlled by adjusting the resistance and capacitance values in the current-limiting resistance circuit;
when the output of the switching power supply is normal, the photoelectric coupler is conducted, the voltage value of the voltage feedback pin of the power supply switching power supply chip returns to a preset normal value, the circuit is recovered to be normal, and the protection is removed.
In the scheme, the protection delay time is set by adjusting the capacitance and resistance values of the power supply protection circuit.
According to the ACDC switching power supply protection circuit and the protection method, the output feedback end voltage of the switching power supply is raised, the switching power supply is effectively protected, and the ACDC switching power supply protection circuit is simple in design, low in cost, good in reliability and strong in applicability.
Drawings
FIG. 1 shows a schematic diagram of an ACDC switching power supply protection circuit;
FIG. 2 shows a flow diagram of an ACDC switching power supply protection method;
detailed description of the invention
In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.
Fig. 1 shows a schematic diagram of an ACDC switching power supply protection circuit according to the present invention.
As shown in fig. 1, a first aspect of the present invention discloses an ACDC switching power supply protection circuit, including: the transformer feedback power supply circuit comprises a rectifying circuit, a current-limiting resistance circuit, a switching power supply circuit, a transformer feedback power supply circuit, an optocoupler feedback circuit and a power supply protection circuit, wherein the input end of the rectifying circuit is connected with an alternating current input voltage, the output end of the rectifying circuit is respectively connected with the input end of the current-limiting resistance circuit and the primary side of the transformer, and the output end of the current-limiting resistance circuit is connected to the power supply input end of the switching power supply circuit; the input end of the transformer feedback power supply circuit is connected with the secondary side of the transformer, and the output end of the transformer feedback power supply circuit is connected with the power supply input end of the switch power supply circuit through the current-limiting resistor; the input of the optocoupler feedback circuit is connected with the other secondary side of the transformer, the output end of the optocoupler feedback circuit is respectively connected to the current compensation control end of the switching power supply circuit and the input end of the power supply protection circuit, and the output end of the power supply protection circuit is connected to the output feedback end of the switching power supply circuit.
In the scheme, the rectifier circuit comprises a rectifier bridge D1, a capacitor EC1, a capacitor EC2, a resistor R3, a resistor R11 and a specific connection relation, wherein alternating-current input voltage is respectively connected to a second connection end, a third connection end and a fourth connection end of the rectifier bridge D1, a 1 st connection end of the rectifier bridge D1 is respectively connected to one end of the capacitor EC1, one end of the resistor R3 and an input end of a current-limiting resistor circuit, a 1 st connection end of the rectifier bridge D1 is further connected to a 17 th connection end of a transformer, the other end of the capacitor EC1 is respectively connected with one end of the capacitor EC2, one end of the resistor R11 and the other end of the resistor R3, and a fifth connection end of the rectifier bridge D1, the other end of the capacitor EC2 and the other end of the resistor R11 are all grounded.
It should be noted that the input of the rectifier bridge D1 may be three-phase or two-phase ac voltage, and the dc voltage of the rectified output is supplied to the switching power supply; the capacitor EC1 and the capacitor EC2 are DClink capacitors.
In this aspect, the current limiting resistor circuit includes: the resistors R1, R6, R10, R9, R5, R4 and R8 have the following specific connection relations: the resistors R1, R6, R10, R9, R5, R4 and R8 are sequentially connected in series, and the input end of the resistor R1 is connected with the output end of the rectifying circuit.
In this scheme, switching power supply circuit includes: the switching power supply chip U1, the power MOS tube Q1, the resistors R2, R7, R14, R15, R16, R18, R19, R20 and R21 are connected with the capacitors C1, C2, C3C5, C7, C6 and C9, the capacitors EC4 and EC5, the diodes DZ1, DZ2, D2 and D5 in a specific connection relationship that: the output end of the rectifier bridge is respectively connected to one end of a R2, one end of a capacitor C1, one end of a capacitor C2, one end of a capacitor C3, the anode of a diode DZ2, the other end of a capacitor C1C 2 is connected with VDC-, the other end of a resistor R2 is connected to one end of the R7, the other end of a resistor R7, the other end of the capacitor C3 and the cathode of a diode DZ2 are connected to the cathode of the diode D2, and the anode of a diode D2 is connected to the 21 st connecting end of the transformer and the D electrode of a power MOS transistor Q1;
a pin 7 of the switching power supply chip U1 is respectively connected to one end of a capacitor C5, one end of a capacitor EC4 and the cathode of a diode DZ1, a pin 5 of the switching power supply chip U1 is respectively connected to the other end of a capacitor C5, the other end of a capacitor EC4, the anode of a diode DZ1, one end of a capacitor C7 and one end of a capacitor EC5, the other end of the capacitor C7 is respectively connected to a pin 4 of the switching power supply chip U1, one end of a resistor R21, the other end of a capacitor EC5 and the other end of a resistor R21 are connected to an 8 pin of a switching power supply chip U1, a 6 pin of the switching power supply chip U1 is connected to one end of a resistor R15 and the cathode of a diode D5 respectively, the anode of a diode D5 is connected to one end of the resistor R14, the other end of a resistor R15 and the other end of the resistor R14 are connected to the G pole of a power MOS transistor Q1, one end of the resistor R16 and one end of a capacitor C6, and the other end of the resistor R16 and the other end of the capacitor C6 are connected to a VDC-connection end;
the 3 pins of the switching power supply chip U1 are connected to one end of a capacitor C9 and one end of a resistor R18 respectively, the other end of the capacitor C9 is connected to a VDC-connection end, the other end of the resistor R18 is connected to one end of a resistor R19, the S pole of a power MOS transistor Q1 and one end of a resistor R20, and the other end of the resistor R19 and the other end of the resistor R20 are connected to the VDC-connection end.
In this scheme, transformer feedback power supply circuit includes: the resistor R12, the diodes D3 and D4, the resistor R13, the capacitor EC3 and the capacitor C4 have the following specific connection relations: the anode of the diode D4 is connected to the 28 th connection end of the transformer, the cathode of the diode D4 is respectively connected to one end of a resistor R13, one end of a capacitor C4, one end of a capacitor EC3 and the anode of a diode D3, and the other ends of the resistor R13, the capacitor C4 and the capacitor EC3 are connected to the 27 th connection end and the VDC-connection end of the transformer;
the cathode of the diode D3 is connected to one end of the resistor R12, and the other end of the resistor R12 is connected to the 7 pin of the switching power supply chip U1.
It should be noted that the capacitor C7 and the capacitor R21 form an RC oscillation clock circuit generating circuit, the capacitor EC4 is a decoupling capacitor, and the DZ2, D2, C3, R2 and R7 form an RCD inverse peak absorption circuit
In this scheme, opto-coupler feedback circuit includes: the photoelectric coupler U2, the reference power chip U3, resistance R17, R23, R24, R25, R28, R30, electric capacity C8, C10, C11, electric capacity EC6, diode D6, the specific relation of connection is: a pin 1 of the switching power supply chip U1 is connected to a pin 4 of the photocoupler U2, a pin 1 of the photocoupler U2 is connected to one end of a resistor R23, the other end of the resistor R23 is respectively connected to one end of a resistor R24, one end of a resistor R25, one end of a capacitor EC6, one end of a capacitor C10, one end of a capacitor C8 and the cathode of a diode D6, the anode of the diode D6 is connected to the 32 th connection end of the transformer, the other end of the capacitor C8 is connected to one end of a resistor R17, and the other end of the resistor R17 is connected to the 32 th connection end of the transformer; a pin 2 of the photocoupler U2 is connected to the other end of the resistor R24, one end of the resistor R28, a pin 3 of the power reference chip U3, the other end of the resistor R28 is connected to one end of the capacitor C11, the other end of the capacitor C11 and the other end of the resistor R25 are both connected to one end of the resistor R30, a pin 1 of the power reference chip U3 is also connected to one end of the resistor R30, and a pin 2 of the power reference chip U3, the other end of the resistor R30, the other end of the capacitor EC6 and the other end of the capacitor C10 are both connected to the 31 th connection end of the transformer and the ground.
It should be noted that, the transformer feedback power supply circuit provides main consumption current for the switching power supply chip in a normal operating state, and is connected to the VCC pin of the switching power supply chip through a current limiting resistor R12, D4 is a rectifier diode, C4, EC3 is a filter capacitor, R13 is a discharge resistor, and D3 isolates the DC high voltage power supply terminal from the feedback power supply terminal.
In this scheme, the power protection circuit includes: triode Q2, resistance R22, R26, R27, R29, electric capacity C12, the concrete relation of connection is: the 8 pin of the switching power supply chip U1 is connected to one end of a resistor R22, the other end of a resistor R22 is connected to one end of a resistor R26 and a 2 pin of the switching power supply chip U1 respectively, the other end of a resistor R26 is connected to one end of a capacitor C12, the other end of the capacitor C12 is connected to a VDC-connection end and an emitter of a triode Q2 respectively, a collector of a triode Q2 is connected to the 2 pin of the switching power supply chip U1, an emitter of a triode Q2 is connected to one end of a resistor R29, a base of a triode Q2 is connected to one end of a resistor R27, and the other end of a resistor R29 and the other end of a resistor R29 are connected to the 3 pin of a photocoupler U2.
In the scheme, the switching power supply chip is a UCX84X chip.
It should be noted that, in the present invention, when the power output is in abnormal conditions such as missing, short circuit, etc., the voltage of the FB (output feedback pin) pin of the switching power supply chip (i.e., pin 2 of the switching power supply chip) is raised, so that the switching power supply is in a continuous restart state, and the restart time of the power supply can be controlled by adjusting the values of the current-limiting resistor, the protection circuit, and the resistor and the capacitor of the protection circuit, so that the power supply device is not damaged, and the switching power supply is in a hiccup state of repeated restart, until the power output is normal, the protection circuit is removed, and the FB pin voltage of the power supply control chip is normal. The invention avoids the occurrence of abnormal conditions such as overvoltage, heating and the like in the self-adjusting process due to the power failure.
Fig. 2 shows a flow chart of an ACDC switching power supply protection method.
As shown in fig. 2, a second aspect of the present invention provides an ACDC switching power supply protection method, for use in an ACDC switching power supply protection circuit as described in any one of the above, the method including the steps of:
s102, when the output of the switching power supply is lost or short-circuited, a photoelectric coupler in the photoelectric coupler feedback circuit is in a non-conductive state, a voltage feedback pin of a chip of the switching power supply is increased to a preset voltage value, and the switching power supply stops working;
s104, adjusting the resistance and capacitance value in the current-limiting resistance circuit to control the restarting time of the switching power supply;
s106, when the switching power supply outputs normal photoelectric coupler to be conducted, and the voltage value of the voltage feedback pin of the power supply switching power supply chip returns to a preset normal value, the circuit is recovered to be normal, and the protection is removed.
The working process of the invention is as follows:
when the circuit normally works, the FB pin of the switching power supply chip is at a low level, the voltage of the VREF pin of the switching power supply chip is 5V, C12 is slowly charged through R22 and R26, the voltage of the FB pin is slowly raised, the switching power supply can be normally started by adjusting the values of R22, R26 and C12, when VOUT reaches the output voltage in each period, an optical coupler (photoelectric coupler) is switched on, on one hand, the COMP pin of the switching power supply chip is pulled down to cause the PWM output of the switching power supply to be switched off, on the other hand, Q2 is driven to be switched on, C12 is enabled to discharge through R26 and Q2, the FB pin is pulled down, and in order to consume the electric quantity of C12 as soon as possible, a small capacitance value C12 and a small resistance value R26 are selected as far as possible under the condition that the current of Q2 is allowed.
In the working process, when the output of the switching power supply VOUT is missing or short-circuited, the optical coupler is always in a non-conductive state, the VREF pin of the switching power supply chip charges C12 through R22 and R26, when the FB pin reaches 2.5V, the switching power supply stops working, the switching power supply chip always keeps no PWM output, the current limiting resistor circuit limits the current supplied to the switching power supply chip by the DC, the current cannot maintain the static power consumption of the switching power supply, the feedback power supply circuit has no feedback at the moment, the voltage of the VCC pin of the switching power supply is gradually reduced to a closing voltage, the current is not consumed and the VREF is powered down after the switching power supply chip is closed, C12 discharges electricity through R22 and R26, the DC charges the EC4 voltage to a starting voltage through the current limiting resistor, the power supply starts to restart, the feedback missing or output short-circuit duration time can be limited by adjusting the values of R22, R26 and C12, ensuring that the device is not damaged by excessive heat from overvoltage.
It should be noted that the conditions for the switching power supply circuit to return to normal are as follows: 1. the short-circuit fault is eliminated, and the VOUT voltage can reach the optical coupler conduction condition; 2. the feedback circuit can normally feed back voltage after being repaired.
In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The above-described device embodiments are merely illustrative, for example, the division of the unit is only a logical functional division, and there may be other division ways in actual implementation, such as: multiple units or components may be combined, or may be integrated into another system, or some features may be omitted, or not implemented. In addition, the coupling, direct coupling or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between the devices or units may be electrical, mechanical or other forms.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units; can be located in one place or distributed on a plurality of network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, all the functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may be separately regarded as one unit, or two or more units may be integrated into one unit; the integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.
Those of ordinary skill in the art will understand that: all or part of the steps for realizing the method embodiments can be completed by hardware related to program instructions, the program can be stored in a computer readable storage medium, and the program executes the steps comprising the method embodiments when executed; and the aforementioned storage medium includes: a mobile storage device, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
Alternatively, the integrated unit of the present invention may be stored in a computer-readable storage medium if it is implemented in the form of a software functional module and sold or used as a separate product. Based on such understanding, the technical solutions of the embodiments of the present invention may be essentially implemented or a part contributing to the prior art may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the methods described in the embodiments of the present invention. And the aforementioned storage medium includes: a removable storage device, a ROM, a RAM, a magnetic or optical disk, or various other media that can store program code.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (9)
1. An ACDC switching power supply protection circuit, comprising: the transformer feedback power supply circuit comprises a rectifying circuit, a current-limiting resistance circuit, a switching power supply circuit, a transformer feedback power supply circuit, an optocoupler feedback circuit and a power supply protection circuit, wherein the input end of the rectifying circuit is connected with an alternating current input voltage, the output end of the rectifying circuit is respectively connected with the input end of the current-limiting resistance circuit and the primary side of the transformer, and the output end of the current-limiting resistance circuit is connected to the power supply input end of the switching power supply circuit; the input end of the transformer feedback power supply circuit is connected with the secondary side of the transformer, and the output end of the transformer feedback power supply circuit is connected with the power supply input end of the switch power supply circuit through the current-limiting resistor; the input end of the optocoupler feedback circuit is connected with the other secondary side of the transformer, the output end of the optocoupler feedback circuit is respectively connected to the current compensation control end of the switching power supply circuit and the input end of the power supply protection circuit, and the output end of the power supply protection circuit is connected to the output feedback end of the switching power supply circuit;
the switching power supply circuit includes: the switching power supply chip U1, the power MOS tube Q1, the resistors R2, R7, R14, R15, R16, R18, R19, R20, R21, the capacitors C1, C2, C3, C5, C7, C6, C9, the capacitors EC4, EC5, the diodes DZ1, DZ2, D2 and D5 have the following specific connection relations: the output end of the rectifier bridge is respectively connected to one end of a R2, one end of a capacitor C1, one end of a capacitor C2, one end of a capacitor C3, the anode of a diode DZ2, the other end of a capacitor C1 and the other end of a capacitor C2 are connected with a VDC-connection end, the other end of a resistor R2 is connected to one end of a resistor R7, the other end of a resistor R7, the other end of the capacitor C3 and the cathode of a diode DZ2 are connected to the cathode of a diode D2, and the anode of a diode D2 is connected to the 21 st connection end of the transformer and the D electrode of a power MOS transistor Q1;
a pin 7 of the switching power supply chip U1 is respectively connected to one end of a capacitor C5, one end of a capacitor EC4 and the cathode of a diode DZ1, a pin 5 of the switching power supply chip U1 is respectively connected to the other end of a capacitor C5, the other end of a capacitor EC4, the anode of a diode DZ1, one end of a capacitor C7 and one end of a capacitor EC5, the other end of the capacitor C7 is respectively connected to a pin 4 of the switching power supply chip U1, one end of a resistor R21, the other end of a capacitor EC5 and the other end of a resistor R21 are connected to an 8 pin of a switching power supply chip U1, a 6 pin of the switching power supply chip U1 is connected to one end of a resistor R15 and the cathode of a diode D5 respectively, the anode of a diode D5 is connected to one end of the resistor R14, the other end of a resistor R15 and the other end of the resistor R14 are connected to the G pole of a power MOS transistor Q1, one end of the resistor R16 and one end of a capacitor C6, and the other end of the resistor R16 and the other end of the capacitor C6 are connected to a VDC-connection end; the 3 pins of the switching power supply chip U1 are connected to one end of a capacitor C9 and one end of a resistor R18 respectively, the other end of the capacitor C9 is connected to a VDC-connection end, the other end of the resistor R18 is connected to one end of a resistor R19, the S pole of a power MOS transistor Q1 and one end of a resistor R20, and the other end of the resistor R19 and the other end of the resistor R20 are connected to the VDC-connection end.
2. The ACDC switching power supply protection circuit as claimed in claim 1, wherein the rectification circuit comprises a rectifier bridge D1, a capacitor EC1, a capacitor EC2, a resistor R3, and a resistor R11, and the specific connection relationship is as follows: the alternating current input voltage is respectively connected to the second connection end, the third connection end and the fourth connection end of the rectifier bridge D1, the 1 st connection end of the rectifier bridge D1 is respectively connected to one end of a capacitor EC1, one end of a resistor R3 and the input end of a current-limiting resistor circuit, the 1 st connection end of the rectifier bridge D1 is also connected to the 17 th connection end of the transformer, the other end of the capacitor EC1 is respectively connected with one end of a capacitor EC2, one end of a resistor R11 and the other end of a resistor R3, and the fifth connection end of the rectifier bridge D1, the other end of the capacitor EC2 and the other end of the resistor R11 are all grounded.
3. The ACDC switching power supply protection circuit of claim 1, wherein the current limiting resistor circuit comprises: the resistors R1, R6, R10, R9, R5, R4 and R8 have the following specific connection relations: the resistors R1, R6, R10, R9, R5, R4 and R8 are sequentially connected in series, and the input end of the resistor R1 is connected with the output end of the rectifying circuit.
4. The ACDC switching power supply protection circuit of claim 1, wherein the transformer feedback power supply circuit comprises: the resistor R12, the diodes D3 and D4, the resistor R13, the capacitor EC3 and the capacitor C4 have the following specific connection relations: the anode of the diode D4 is connected to the 28 th connection end of the transformer, the cathode of the diode D4 is respectively connected to one end of a resistor R13, one end of a capacitor C4, one end of a capacitor EC3 and the anode of a diode D3, and the other ends of the resistor R13, the capacitor C4 and the capacitor EC3 are connected to the 27 th connection end and the VDC-connection end of the transformer; the cathode of the diode D3 is connected to one end of the resistor R12, and the other end of the resistor R12 is connected to the 7 pin of the switching power supply chip U1.
5. The ACDC switching power supply protection circuit of claim 4, wherein the optocoupler feedback circuit comprises: the photoelectric coupler U2, the reference power chip U3, resistance R17, R23, R24, R25, R28, R30, electric capacity C8, C10, C11, electric capacity EC6, diode D6, the specific relation of connection is: a pin 1 of the switching power supply chip U1 is connected to a pin 4 of the photocoupler U2, a pin 1 of the photocoupler U2 is connected to one end of a resistor R23, the other end of the resistor R23 is respectively connected to one end of a resistor R24, one end of a resistor R25, one end of a capacitor EC6, one end of a capacitor C10, one end of a capacitor C8 and the cathode of a diode D6, the anode of the diode D6 is connected to the 32 th connection end of the transformer, the other end of the capacitor C8 is connected to one end of a resistor R17, and the other end of the resistor R17 is connected to the 32 th connection end of the transformer; a pin 2 of the photocoupler U2 is connected to the other end of the resistor R24, one end of the resistor R28, a pin 3 of the power reference chip U3, the other end of the resistor R28 is connected to one end of the capacitor C11, the other end of the capacitor C11 and the other end of the resistor R25 are both connected to one end of the resistor R30, a pin 1 of the power reference chip U3 is also connected to one end of the resistor R30, and a pin 2 of the power reference chip U3, the other end of the resistor R30, the other end of the capacitor EC6 and the other end of the capacitor C10 are both connected to the 31 th connection end of the transformer and the ground.
6. The ACDC switching power supply protection circuit of claim 5, wherein the power supply protection circuit comprises: triode Q2, resistance R22, R26, R27, R29, electric capacity C12, the concrete relation of connection is: the 8 pin of the switching power supply chip U1 is connected to one end of a resistor R22, the other end of the resistor R22 is connected to one end of a resistor R26 and the 2 pin of the switching power supply chip U1 respectively, the other end of the resistor R26 is connected to one end of a capacitor C12, the other end of the capacitor C12 is connected to a VDC-connection end and the emitter of a triode Q2 respectively, the collector of a triode Q2 is connected to the 2 pin of the switching power supply chip U1, the emitter of a triode Q2 is connected to one end of the resistor R29, the base of a triode Q2 is connected to one end of a resistor R27, and the other end of the resistor R29 and the other end of the resistor R29 are connected to the 3 pin of a photocoupler U2.
7. The ACDC switching power supply protection circuit as claimed in claim 6, wherein the switching power supply chip is a UCX84X chip.
8. An ACDC switching power supply protection method applied to the ACDC switching power supply protection circuit according to any one of claims 1 to 7, the method comprising the steps of:
when the output of the switching power supply is lost or short-circuited, a photoelectric coupler in the photoelectric coupler feedback circuit is in a non-conductive state, a voltage feedback pin of a chip of the switching power supply is increased to a preset voltage value, and the switching power supply stops working; the restarting time of the switching power supply is controlled by adjusting the resistance and capacitance values in the current-limiting resistance circuit; when the output of the switching power supply is normal, the photoelectric coupler is conducted, the voltage value of the voltage feedback pin of the power supply switching power supply chip returns to a preset normal value, the circuit is recovered to be normal, and the protection is removed.
9. The ACDC switching power supply protection method of claim 8, wherein the protection delay time is set by adjusting values of a capacitor and a resistor of the power supply protection circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910675361.9A CN110492442B (en) | 2019-07-25 | 2019-07-25 | ACDC switching power supply protection circuit and protection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910675361.9A CN110492442B (en) | 2019-07-25 | 2019-07-25 | ACDC switching power supply protection circuit and protection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110492442A CN110492442A (en) | 2019-11-22 |
| CN110492442B true CN110492442B (en) | 2021-07-30 |
Family
ID=68548224
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910675361.9A Active CN110492442B (en) | 2019-07-25 | 2019-07-25 | ACDC switching power supply protection circuit and protection method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110492442B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113922450B (en) * | 2021-10-13 | 2023-10-13 | 苏州贝克微电子股份有限公司 | Power supply circuit with low noise |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN208924105U (en) * | 2018-11-22 | 2019-05-31 | 无锡全裕电子科技有限公司 | A kind of switching power circuit module of auto sleep |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3883826B2 (en) * | 2001-07-18 | 2007-02-21 | ソニー株式会社 | Switching power supply |
| US8942012B2 (en) * | 2012-01-31 | 2015-01-27 | Semiconductor Components Industries, Llc | Method of forming a switched mode power supply controller device with an off mode and structure therefor |
| CN103326325B (en) * | 2013-06-05 | 2016-02-24 | 广州凯盛电子科技有限公司 | Switching Power Supply output short-circuit and under-voltage protecting circuit |
| CN203368331U (en) * | 2013-06-21 | 2013-12-25 | 深圳市晶福源电子技术有限公司 | Switch power supply with input under-voltage protection function |
| CN203827205U (en) * | 2013-08-30 | 2014-09-10 | 昂宝电子（上海）有限公司 | Flyback switching power circuit |
| CN204993070U (en) * | 2015-09-23 | 2016-01-20 | 深圳市港祥辉电子有限公司 | Can realize undervoltage protection's switching power supply |
| JP6747203B2 (en) * | 2016-09-15 | 2020-08-26 | 富士電機株式会社 | Switching power supply |
| CN206259864U (en) * | 2016-11-07 | 2017-06-16 | 深圳欧陆通电子有限公司 | Switching power source control circuit and Switching Power Supply |
| CN108667320B (en) * | 2018-06-22 | 2024-02-20 | 江苏理工学院 | Switch power supply with overcurrent protection and self-reset |
-
2019
- 2019-07-25 CN CN201910675361.9A patent/CN110492442B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN208924105U (en) * | 2018-11-22 | 2019-05-31 | 无锡全裕电子科技有限公司 | A kind of switching power circuit module of auto sleep |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110492442A (en) | 2019-11-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101414764B (en) | Method and apparatus to reduce the volume required for bulk capacitance in a power supply | |
| CN101677211B (en) | Flyback converter with forward converter reset clampinitialization period | |
| CN111799995B (en) | Control circuit for input filter capacitor in switch mode power supply | |
| CN101277057B (en) | Overload protection delay circuit for switching power supply | |
| CN110492442B (en) | ACDC switching power supply protection circuit and protection method | |
| US20210219397A1 (en) | Input detection an protection circuit an ac electronic ballast for hid lamps | |
| CN111193317A (en) | Power-down protection circuit for terminal equipment | |
| CN112039028A (en) | Remote control instruction and bus under-voltage protection circuit with strong anti-jamming capability | |
| CN110880877A (en) | Integrated isolation power supply circuit for communication type circuit breaker | |
| CN107332435B (en) | Power supply circuit of pulse width modulation chip and switching power supply | |
| CN113991611B (en) | Switch power supply and protection circuit thereof | |
| CN213782946U (en) | Charging circuit and uninterruptible power supply comprising same | |
| CN210405097U (en) | Wide voltage range DC input switch power supply | |
| CN112054590B (en) | Capacitor direct-current guarantee power supply | |
| CN212115181U (en) | Ultra-fast starting power supply | |
| CN209375464U (en) | Inverse-excitation type switch power-supply adapter | |
| CN216252529U (en) | Overcurrent stabilizing switch | |
| RU2037249C1 (en) | System of uninterrupted power supply | |
| CN208285232U (en) | Regulated power supply is protected in constant current | |
| CN212695914U (en) | Switching power supply and electrical equipment | |
| CN219181405U (en) | Electrical switching power supply device | |
| CN214626822U (en) | Universal adapter | |
| CN217508589U (en) | Power supply circuit and display device | |
| CN212850301U (en) | Power supply circuit of Bluetooth circuit breaker | |
| CN110729771B (en) | Self-powered device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: ACDC switching power supply protection circuit and protection method Effective date of registration: 20211203 Granted publication date: 20210730 Pledgee: Hangzhou High-tech Financing Guarantee Co.,Ltd. Pledgor: HANGZHOU ZHOUJU ELECTRONIC TECHNOLOGICAL Co.,Ltd. Registration number: Y2021980014045 |
|
| PC01 | Cancellation of the registration of the contract for pledge of patent right |
Date of cancellation: 20220322 Granted publication date: 20210730 Pledgee: Hangzhou High-tech Financing Guarantee Co.,Ltd. Pledgor: HANGZHOU ZHOUJU ELECTRONIC TECHNOLOGICAL Co.,Ltd. Registration number: Y2021980014045 |
|
| PC01 | Cancellation of the registration of the contract for pledge of patent right | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: ACDC switching power supply protection circuit and protection method Effective date of registration: 20220322 Granted publication date: 20210730 Pledgee: Shanghai Guotai Junan Securities Asset Management Co.,Ltd. Pledgor: HANGZHOU ZHOUJU ELECTRONIC TECHNOLOGICAL Co.,Ltd. Registration number: Y2022990000159 |
|
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PC01 | Cancellation of the registration of the contract for pledge of patent right |
Date of cancellation: 20221220 Granted publication date: 20210730 Pledgee: Shanghai Guotai Junan Securities Asset Management Co.,Ltd. Pledgor: HANGZHOU ZHOUJU ELECTRONIC TECHNOLOGICAL Co.,Ltd. Registration number: Y2022990000159 |
|
| PC01 | Cancellation of the registration of the contract for pledge of patent right | ||
| EE01 | Entry into force of recordation of patent licensing contract | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20191122 Assignee: Hangzhou Jintou Finance Leasing Co.,Ltd. Assignor: HANGZHOU ZHOUJU ELECTRONIC TECHNOLOGICAL Co.,Ltd. Contract record no.: X2022980028697 Denomination of invention: An ACDC switching power supply protection circuit and protection method Granted publication date: 20210730 License type: Exclusive License Record date: 20230112 |
|
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: An ACDC switching power supply protection circuit and protection method Effective date of registration: 20230115 Granted publication date: 20210730 Pledgee: Hangzhou Jintou Finance Leasing Co.,Ltd. Pledgor: HANGZHOU ZHOUJU ELECTRONIC TECHNOLOGICAL Co.,Ltd. Registration number: Y2023980031393 |
|
| EC01 | Cancellation of recordation of patent licensing contract | ||
| EC01 | Cancellation of recordation of patent licensing contract |
Assignee: Hangzhou Jintou Finance Leasing Co.,Ltd. Assignor: HANGZHOU ZHOUJU ELECTRONIC TECHNOLOGICAL Co.,Ltd. Contract record no.: X2022980028697 Date of cancellation: 20240327 |
|
| PC01 | Cancellation of the registration of the contract for pledge of patent right | ||
| PC01 | Cancellation of the registration of the contract for pledge of patent right |
Granted publication date: 20210730 Pledgee: Hangzhou Jintou Finance Leasing Co.,Ltd. Pledgor: HANGZHOU ZHOUJU ELECTRONIC TECHNOLOGICAL Co.,Ltd. Registration number: Y2023980031393 |