CN112701662B - Overvoltage protection circuit, switching power supply circuit, and power supply device - Google Patents
Overvoltage protection circuit, switching power supply circuit, and power supply device Download PDFInfo
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- CN112701662B CN112701662B CN202011445461.1A CN202011445461A CN112701662B CN 112701662 B CN112701662 B CN 112701662B CN 202011445461 A CN202011445461 A CN 202011445461A CN 112701662 B CN112701662 B CN 112701662B
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- 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
- H02H7/1213—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 DC-DC converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
- H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
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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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The application discloses overvoltage crowbar, switching power supply circuit and power supply unit, through the first turn-on signal of voltage detection subassembly output according to the detection voltage of power supply circuit output, first switching element exports the third when inputing first turn-on signal or second turn-on signal, and according to first voltage output stop signal with control when inputing the second turn-on signal power supply circuit stops converting input voltage into output voltage to and second switching element exports second turn-on signal and first voltage according to detection voltage when inputing the third turn-on signal, and keeps exporting second turn-on signal and first voltage according to inside mains voltage, can continuously break off power supply circuit's output when power supply circuit appears the overvoltage, the overvoltage crowbar of this application is simple effective, and the response is fast when power supply circuit appears the overvoltage.
Description
Technical Field
The application belongs to the technical field of power protection, and particularly relates to an overvoltage protection circuit, a switching power supply circuit and a power supply device.
Background
The switching power supply is very commonly applied to industrial automation products such as a frequency converter and the like, and particularly widely applied as an auxiliary power supply to supply power to a circuit of the whole system; when the switching power supply is over-voltage detected and increased to a high level due to a feedback loop fault or a device fault, it may cause damage to a load device of the switching power supply or harm to a human body.
The conventional switching power supply generally performs overvoltage protection on the detection voltage of the switching power supply through a secondary-side protection circuit, but the conventional switching power supply has the problems of complex circuit structure, long reaction time, high control overvoltage and the like, and the cost is increased due to more circuit using devices.
Disclosure of Invention
The application aims to provide an overvoltage protection circuit, and aims to solve the problems that a traditional overvoltage protection circuit is complex in circuit, too long in reaction time and high in control overvoltage.
A first aspect of an embodiment of the present application provides an overvoltage protection circuit, including:
the voltage detection component is configured to receive a detection voltage output by the power circuit and output a first conduction signal according to the detection voltage;
a first switch component connected with the voltage detection component and configured to output a third on signal when the first on signal or the second on signal is input, and output a cut-off signal according to the first voltage to control the power circuit to stop converting the input voltage into the output voltage when the second on signal is input; and
a second switching element connected to the first switching element and configured to output the second turn-on signal and the first voltage according to the detection voltage when the third turn-on signal is input, and maintain the output of the second turn-on signal and the first voltage according to an internal power voltage;
wherein the detection voltage and the output voltage are positively correlated.
In one embodiment, the voltage detection component includes a zener diode;
the cathode of the voltage stabilizing diode is connected to the detection voltage input end of the voltage detection assembly, and the anode of the voltage stabilizing diode is connected to the first conduction signal output end of the voltage detection assembly.
In one embodiment, the first switch assembly includes a first field effect transistor and a first resistor;
the base electrode of the first field effect tube is connected with the first end of the first resistor and is connected to the first on-signal/second on-signal input end of the first switch assembly, the emitting electrode of the first field effect tube is connected with the second end of the first resistor and is connected to the off-signal output end of the first switch assembly, and the collecting electrode of the first field effect tube is connected to the third on-signal output end of the first switch assembly and the first voltage input end of the first switch assembly.
In one embodiment, the first switch assembly further includes a first capacitor;
a first end of the first capacitor is connected to the first on signal/second on signal input end of the first switch assembly, and a second end of the first capacitor is connected to the off signal output end of the first switch assembly.
In one embodiment, the second switch assembly includes a second fet, a second resistor, a third resistor, and a second capacitor;
the base of the second field effect transistor, the first end of the second capacitor and the first end of the third resistor are connected in common and connected to the third conduction signal input end of the second switch component and the first voltage output end of the second switch component, the emitter of the second field effect transistor, the second end of the second capacitor, the first end of the second resistor and the second end of the third resistor are connected in common, the collector of the second field effect transistor is connected to the second conduction signal output end of the second switch component, and the second end of the second resistor is connected to the detection voltage/internal power supply voltage input end of the second switch component.
A second aspect of the embodiments of the present application provides a switching power supply circuit, including a power supply circuit and the overvoltage protection circuit according to any one of the first aspects, where the power supply circuit includes a control circuit, an output circuit, and a feedback circuit;
the control circuit is respectively connected with the output circuit, the feedback circuit and the overvoltage protection circuit and is configured to stop outputting pulse signals according to the cut-off signals and regulate the pulse signals according to feedback signals;
the output circuit configured to output the internal power supply voltage in accordance with the input voltage, convert the input voltage into the detection voltage and the output voltage in accordance with the pulse signal when the pulse signal is input, and stop outputting the detection voltage and the output voltage when the pulse signal stops being input;
the feedback circuit is configured to generate the feedback signal according to the output voltage.
In one embodiment, the output circuit includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a first diode, a second diode, a third diode, a first transformer, and a second transformer;
the first end of the sixth capacitor, the first end of the seventh resistor and the first end of the primary winding of the first transformer are connected in common and connected to the input voltage input end of the output circuit, the second end of the seventh resistor is connected with the first end of the sixth resistor, the second end of the sixth resistor and the first end of the fourth capacitor are connected and connected to the internal power supply voltage output end of the output circuit, the second end of the primary winding of the first transformer is connected to the pulse signal input end of the output circuit, the first end of the fifth resistor is connected with the first end of the third capacitor and connected to the detection voltage output end of the output circuit, the second end of the fifth resistor is connected with the negative electrode of the first diode, and the positive electrode of the first diode is connected with the first end of the secondary winding of the second transformer, the first end of the primary winding of the second transformer, the first end of the fifth capacitor, the cathode of the second diode, the cathode of the third diode and the first end of the eighth resistor are connected in common, the second end of the fifth capacitor is connected with the first end of the fourth resistor, the second end of the fourth resistor, the anode of the second diode and the first end of the secondary winding of the first transformer are connected in common, the second end of the eighth resistor is connected with the first end of the seventh capacitor, the second end of the primary winding of the second transformer, the first end of the eighth capacitor and the first end of the ninth resistor are connected in common and connected to the output voltage output end of the output circuit, the second end of the secondary winding of the second transformer, the second end of the third capacitor, the second end of the fourth capacitor and the second end of the sixth capacitor are all connected with the first power ground, and the second end of the seventh capacitor, the second end of the eighth capacitor, the second end of the ninth resistor, the anode of the third diode and the second end of the secondary winding of the first transformer are all connected with a second power ground.
In one embodiment, the feedback circuit comprises a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a ninth capacitor, an optocoupler and a controllable precision voltage regulator;
the first end of the tenth resistor and the first end of the eleventh resistor are connected and connected to the output voltage input end of the feedback circuit, the second end of the tenth resistor, the first end of the twelfth resistor and the positive electrode of the optocoupler are connected in common, the second end of the eleventh resistor, the first end of the ninth capacitor, the first end of the fourteenth resistor and the enabling end of the controllable precise voltage stabilizing source are connected in common, the second end of the twelfth resistor, the negative electrode of the optocoupler, the first end of the thirteenth resistor and the negative electrode of the controllable precise voltage stabilizing source are connected in common, the second end of the thirteenth resistor and the second end of the ninth capacitor are connected, the collector of the optocoupler is connected to the feedback signal output end of the feedback circuit, the emitter of the optocoupler is connected with the first power ground, and the second end of the fourteenth resistor and the positive electrode of the controllable precise voltage stabilizing source are both connected with the second power ground.
In one embodiment, the control circuit includes a pulse chip, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor and a third field effect transistor;
the output end of the pulse chip is connected with the first end of the eighteenth resistor, the sampling end of the pulse chip, the first end of the twelfth capacitor and the first end of the nineteenth resistor are connected in common, the voltage feedback end of the pulse chip, the first end of the fifteenth resistor, the first end of the sixteenth resistor and the first end of the tenth capacitor are connected in common, the compensation end of the pulse chip and the second end of the fifteenth resistor are connected and connected to the feedback signal input end of the control circuit, the power end of the pulse chip is connected to the internal power voltage input end of the control circuit, the oscillation frequency end of the pulse chip, the second end of the sixteenth resistor and the first end of the eleventh capacitor are connected in common, the second end of the eighteenth resistor, the gate of the third field effect transistor and the first end of the twentieth resistor are connected in common, the first end of the seventeenth resistor, the second end of the nineteenth resistor, the second end of the twentieth resistor and the source of the third field effect transistor are connected in common, the drain of the third field effect transistor is connected to the pulse signal output end of the control circuit, the pulse chip, the second end of the seventeenth resistor, the second end of the power resistor and the eleventh capacitor are connected with the ground.
A third aspect of embodiments of the present application provides a power supply apparatus including the switching power supply circuit according to any one of the second aspects.
Compared with the prior art, the application has the beneficial effects that: the overvoltage protection circuit is simple and effective, has quick response when overvoltage occurs in the power circuit, can control the power overvoltage to act when a smaller value is reached, and has good overvoltage protection effect and low manufacturing cost.
Drawings
FIG. 1 is an exemplary functional block diagram of an over-voltage protection circuit provided by an embodiment of the present application;
FIG. 2 is an exemplary circuit schematic of an over-voltage protection circuit provided by an embodiment of the present application;
fig. 3 is an exemplary functional block diagram of a switching power supply circuit provided in an embodiment of the present application;
fig. 4 is an exemplary circuit schematic diagram of a switching power supply circuit according to an embodiment of the present application.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
Fig. 1 shows a first exemplary schematic block diagram of an overvoltage protection circuit 100 provided in an embodiment of the present application, and for convenience of illustration, only the portions related to the embodiment are shown, and detailed as follows:
the overvoltage protection circuit 100 includes a voltage detection component 110, a first switching component 120, and a second switching component 130.
The voltage detection component 110 is configured to receive a detection voltage output by the power circuit and output a first turn-on signal according to the detection voltage.
The first switching element 120 is connected to the voltage detecting element 110, and configured to output a third on signal when the first on signal or the second on signal is input, and output an off signal according to the first voltage when the second on signal is input.
And a second switching element 130 connected to the first switching element 120, configured to output the second turn-on signal and the first voltage according to the detection voltage when the third turn-on signal is input, and maintain the output of the second turn-on signal and the first voltage according to the internal power voltage.
Wherein the detection voltage and the output voltage are positively correlated.
In this embodiment, when an overvoltage occurs in the power circuit, the voltage detection element 110 receives a detection voltage output from the power circuit, and the detection voltage is greater than a preset value, the voltage detection element 110 outputs a first turn-on signal to the first switch element 120, the first switch element 120 turns on and outputs a third turn-on signal to the second switch element 130 to turn on the second switch element 130 when the first turn-on signal is input, the second switch element 130 generates a second turn-on signal and a first voltage according to the detection voltage when turned on, the first switch element 120 generates a turn-off signal according to the first voltage and outputs the turn-on signal to the power circuit to control the power circuit to stop converting the input voltage into the output voltage, and the second turn-on signal output from the second switch element 130 acts on the first switch element 120 to turn on the first switch element 120 and outputs the third turn-on signal to the second switch element 130 according to the second turn-on signal, so that the first switch element 120 and the second switch element 130 latch with each other, when the power circuit stops converting the detection voltage into the output voltage to the output voltage, the second switch element 120 in a state to maintain the second turn-on signal to output when the power circuit is switched on, and the second switch element 120 is switched to maintain the second switch element to output a voltage, thereby to enable the power circuit to maintain the power circuit to output a simple over voltage, and to maintain the power circuit to output a simple over voltage when the second switch element 100 is switched on state, the overvoltage protection effect is good and the manufacturing cost is low.
In one embodiment, the first switch element 120 is further configured to output a turn-off signal according to the first voltage when the first turn-on signal is input to control the power circuit to stop converting the input voltage into the output voltage.
In the present embodiment, the first switch element 120 outputs the off signal when the first on signal is input, so as to shorten the time for controlling the power circuit to stop converting the input voltage into the output voltage.
In one embodiment, the internal power supply voltage is generated from an input voltage of the power supply circuit.
Referring to fig. 2, in an embodiment, the voltage detection component 110 includes a zener diode Z1.
The cathode of the zener diode Z1 is connected to the detection voltage input terminal of the voltage detection component 110, and the anode of the zener diode Z1 is connected to the first turn-on signal output terminal of the voltage detection component 110.
Referring to fig. 2, in an embodiment, the first switching element 120 includes a first fet Q1 and a first resistor R1.
A base of the first field effect transistor Q1 is connected to a first end of the first resistor R1 and connected to a first on signal/second on signal input end of the first switch component 120, an emitter of the first field effect transistor Q1 is connected to a second end of the first resistor R1 and connected to a cut-off signal output end of the first switch component 120, and a collector of the first field effect transistor Q1 is connected to a third on signal output end of the first switch component 120 and a first voltage input end of the first switch component 120.
Referring to fig. 2, in an embodiment, the first switch element 120 further includes a first capacitor C1.
A first end of the first capacitor C1 is connected to the first on signal/second on signal input end of the first switch element 120, and a second end of the first capacitor C1 is connected to the off signal output end of the first switch element 120
Referring to fig. 2, in an embodiment, the second switching element 130 includes a second fet Q2, a second resistor R2, a third resistor R3, and a second capacitor C2.
A base of the second field effect transistor Q2, a first end of the second capacitor C2, and a first end of the third resistor R3 are commonly connected to a third on signal input terminal of the second switch device 130 and a first voltage output terminal of the second switch device 130, an emitter of the second field effect transistor Q2, a second end of the second capacitor C2, a first end of the second resistor R2, and a second end of the third resistor R3 are commonly connected, a collector of the second field effect transistor Q2 is connected to a second on signal output terminal of the second switch device 130, and a second end of the second resistor R2 is connected to a detection voltage/internal power voltage input terminal of the second switch device 130.
The overvoltage protection circuit 100 shown in fig. 2 is described with reference to the working principle, when the output voltage of the power circuit has an overvoltage, the voltage regulator diode Z1 is turned on by the detection voltage, the detection voltage acts on the voltage regulator diode Z1 to generate a first current, the divided voltage of the first current (a first conducting signal) at the first resistor R1 acts on the base of the first field effect transistor Q1 to turn on the first field effect transistor Q1, and after the first field effect transistor Q1 is turned on, the detection voltage acts on the second resistor R2, the third resistor R3 and the first field effect transistor Q1 to generate a second current, the second current acts on the first field effect transistor Q1 to generate a first voltage (a third conducting signal) and acts on the base of the second field effect transistor Q2 to turn on the second field effect transistor Q2, and the second current generates a first voltage under the actions of the second resistor R2, the third resistor R3 and the second capacitor C2, at this time, the first voltage generates a cut-off signal through the first field effect transistor Q1 and is output to the power circuit to stop the power circuit from converting the input voltage into the output voltage, at this time, the detection voltage is 0, the zener diode Z1 is cut off, the first field effect transistor Q1 and the second field effect transistor Q2 are both turned on, the internal power voltage acts on the second resistor R2, the second field effect transistor Q2 and the first resistor R1 to generate a third current, the voltage division of the third current (a second turn-on signal) on the first resistor R1 acts on the base of the first field effect transistor Q1 to keep the first field effect transistor Q1 turned on, because the first field effect transistor Q1 is turned on, the internal power voltage acts on the second resistor R2, the third resistor R3 and the first field effect transistor Q1 to generate a fourth current, at this time, the fourth current generates the first voltage under the action of the second resistor R2, the third resistor R3 and the second capacitor C2, the output of the first voltage after passing through the first field effect transistor Q1 and the output of the second on signal after passing through the first resistor R1 jointly form a cut-off signal and output to the power circuit, so that the power circuit stops converting the input voltage into the output voltage, therefore, the first field effect transistor Q1 and the second field effect transistor Q2 both maintain on under the effect of the internal power voltage, meanwhile, the second resistor R2 and the third resistor R3 maintain to output the first voltage to the first field effect transistor Q1 according to the internal power voltage, the second resistor R2 and the second field effect transistor Q2 maintain to output the second on signal to the first resistor R1 according to the internal power voltage, and therefore, the emitter of the first field effect transistor Q1 maintains to output the cut-off signal according to the second on signal and the first voltage.
The overvoltage protection circuit 100 of the embodiment has the advantages of small number of electronic components and fast response of overvoltage protection.
Referring to fig. 3, an embodiment of the present application further provides a switching power supply circuit, which includes a power supply circuit and the overvoltage protection circuit 100 according to any of the above embodiments, where the power supply circuit includes a control circuit 400, an output circuit 200, and a feedback circuit 300.
And a control circuit 400, which is respectively connected with the output circuit 200, the feedback circuit 300 and the overvoltage protection circuit 100, and is configured to stop outputting the pulse signal according to the cutoff signal and adjust the pulse signal according to the feedback signal.
An output circuit 200 configured to output an internal power supply voltage according to an input voltage, convert the input voltage into a detection voltage and an output voltage according to a pulse signal when the pulse signal is input, and stop outputting the detection voltage and the output voltage when the input of the pulse signal is stopped.
A feedback circuit 300 configured to generate a feedback signal according to the output voltage.
Because the switching power supply circuit of the present embodiment includes the overvoltage protection circuit 100 of any one of the above embodiments, the switching power supply circuit of the present embodiment at least includes the corresponding advantages of the overvoltage protection circuit 100 of any one of the above embodiments.
In this embodiment, the control circuit 400 outputs a pulse signal to the output circuit 200 according to a preset voltage value, so that the output circuit 200 converts an input voltage into a detection voltage and an output voltage according to the pulse signal, the feedback circuit 300 generates a feedback signal according to the output voltage and outputs the feedback signal to the control circuit 400, so that the control circuit 400 adjusts the output pulse signal according to the feedback signal, so as to achieve an effect of adjusting the output voltage, when the output voltage has an overvoltage, the overvoltage protection circuit 100 outputs a cut-off signal to the control circuit 400 to charge the control circuit 400, and when the control circuit 400 is charged to reach a preset value, the control circuit 400 stops outputting the pulse signal to the output circuit 200, so as to control the output circuit 200 to stop converting the input voltage into the output voltage, thereby achieving an effect of protecting an electrical load and a switching power supply circuit.
Referring to fig. 4, in an embodiment, the output circuit 200 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a first diode D1, a second diode D2, a third diode D3, a first transformer T1, and a second transformer T2.
The first end of the sixth capacitor C6, the first end of the seventh resistor R7 and the first end of the primary winding of the first transformer T1 are connected in common and are connected to the input voltage input end of the output circuit 200, the second end of the seventh resistor R7 is connected with the first end of the sixth resistor R6, the second end of the sixth resistor R6 and the first end of the fourth capacitor C4 are connected and are connected to the internal power voltage output end of the output circuit 200, the second end of the primary winding of the first transformer T1 is connected to the pulse signal input end of the output circuit 200, the first end of the fifth resistor R5 is connected with the first end of the third capacitor C3 and is connected to the detection voltage output end of the output circuit 200, the second end of the fifth resistor R5 is connected with the cathode of the first diode D1, the anode of the first diode D1 is connected with the first end of the secondary winding of the second transformer T2, the first end of the primary winding of the second transformer T2, the first end of the fifth capacitor C5, the cathode of the second diode D2, the cathode of the third diode D3 and the first end of the eighth resistor R8 are connected in common, the second end of the fifth capacitor C5 is connected with the first end of the fourth resistor R4, the second end of the fourth resistor R4, the anode of the second diode D2 and the first end of the secondary winding 10 of the first transformer T1 are connected in common, the second end of the eighth resistor R8 is connected with the first end of the seventh capacitor C7, the second end of the primary winding of the second transformer T2, the first end of the eighth capacitor C8, and the first end of the ninth resistor R9 are connected to the output voltage output end of the output circuit 200, the second end of the secondary winding of the second transformer T2, the second end of the third capacitor C3, the second end of the fourth capacitor C4, and the second end of the sixth capacitor C6 are all connected to the first power ground, the second end of the seventh capacitor C7, the second end of the eighth capacitor C8, the first end of the ninth resistor R9, and the second end of the sixth capacitor C6 are all connected to the first power ground, A second end of the ninth resistor R9, an anode of the third diode D3, and a second end of the secondary winding of the first transformer T1 are all connected to the second power ground.
Referring to fig. 4, in an embodiment, the feedback circuit 300 includes a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a ninth capacitor C9, an optocoupler PC1 and a controllable precision regulator U2.
A first end of a tenth resistor R10 and a first end of an eleventh resistor R11 are connected and connected to an output voltage input end of the feedback circuit 300, a second end of the tenth resistor R10, a first end of a twelfth resistor R12 and an anode of the optocoupler PC1 are connected in common, a second end of the eleventh resistor R11, a first end of a ninth capacitor C9, a first end of a fourteenth resistor R14 and an enable end of the controllable precision regulator U2 are connected in common, a second end of the twelfth resistor R12, a cathode of the optocoupler PC1, a first end of a thirteenth resistor R13 and a cathode of the controllable precision regulator U2 are connected in common, a second end of the thirteenth resistor R13 is connected with a second end of the ninth capacitor C9, a collector of the optocoupler PC1 is connected to a feedback signal output end of the feedback circuit 300, an emitter of the optocoupler PC1 is connected to a first power ground, and a second end of the fourteenth resistor R14 and an anode of the controllable precision regulator U2 are connected to a second power ground.
Referring to fig. 4, in an embodiment, the control circuit 400 includes a pulse chip U1, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, a tenth capacitor C10, an eleventh capacitor C11, a twelfth capacitor C12, and a third fet Q3.
An output end OUT of the pulse chip U1 is connected with a first end of an eighteenth resistor R18, a sampling end CS of the pulse chip U1, a first end of a twelfth capacitor C12 and a first end of a nineteenth resistor R19 are connected in common, a voltage feedback end VREF of the pulse chip U1, a first end of a fifteenth resistor R15, a first end of a sixteenth resistor R16 and a first end of a tenth capacitor C10 are connected in common, a compensation end COMP of the pulse chip U1 and a second end of the fifteenth resistor R15 are connected and connected to a feedback signal input end of the control circuit 400, a power supply end VCC of the pulse chip U1 is connected to an internal power supply voltage input end of the control circuit 400, an oscillation frequency end RT/CT of the pulse chip U1, a second end of the sixteenth resistor R16 and a first end of an eleventh capacitor C11 are connected in common, a second end of the eighteenth resistor R18, a gate of a third field effect transistor Q3 and a first end of the twentieth resistor R20 are connected in common, a first end of a seventeenth resistor R17, a second end of the seventeenth resistor R19, a second end of the twentieth resistor R3, a drain terminal of the pulse chip U1 and a source terminal of the pulse chip U1 are connected to a ground terminal of the twelfth capacitor C10, a source terminal of the twelfth capacitor C10 and a seventeenth capacitor C10.
In this embodiment, the output terminal OUT of the pulse chip U1 outputs a pulse to the gate of the third fet Q3 according to a preset voltage value, the third fet Q3 is turned on when the pulse is on the rising edge and turned off when the pulse is on the falling edge, when the third fet Q3 is turned on, the primary winding of the first transformer T1 is connected to the first power ground and turned on, the input voltage acts on the primary winding of the first transformer T1, the secondary winding of the first transformer T1 induces a first voltage, the first voltage is output to the primary winding of the second transformer T2 through the second diode D2, the primary winding of the second transformer T2 charges according to the first voltage and generates an output voltage, the output voltage acts on the positive electrode of the tenth resistor R10, the eleventh resistor R11, the twelfth resistor R12, the thirteenth resistor R13, the fourteenth resistor R14, the ninth capacitor C9 and the negative electrode of the controllable precision regulator U2 in optical coupling with the positive electrode of the PC1 and the negative electrode of the PC1, the light emitting part of the optical coupler PC1 emits light under the action of the output voltage to enable the light receiving part of the optical coupler PC1 to generate current (feedback signal) and output the current to the compensation end COMP of the pulse chip U1 and the voltage feedback end VREF of the pulse chip U1, the pulse chip U1 adjusts parameters of output pulses according to the feedback signal to enable the output voltage to be closer to the preset voltage, when overvoltage occurs, the second voltage induced by the secondary winding of the second transformer T2 is converted into detection voltage through the first diode D1 and the fifth resistor R5 to act on the voltage stabilizing diode Z1 to enable the voltage stabilizing diode Z1 to be conducted, therefore, the first field effect tube Q1 and the second field effect tube Q2 are conducted and latched and output a cut-off signal to the twelfth capacitor C12, the twelfth capacitor C12 is charged under the action of the cut-off signal, and when the voltage of the twelfth capacitor C12 acting on the sampling end CS of the pulse chip U1 is larger than the preset value, the output end OUT of the pulse chip U1 stops outputting pulses to keep the third field effect transistor Q3 cut off, and because the input voltage charges the fourth capacitor C4 through the sixth resistor R6 and the seventh resistor R7 to generate the internal power supply voltage, a cut-off signal exists along with the input voltage, the voltage of the twelfth capacitor C12 acting on the sampling end CS of the pulse chip U1 keeps the output end of the pulse chip U1 stopping outputting pulses until the input voltage is removed; in addition, since the overvoltage protection circuit 100 of the present application acts on the primary winding of the first transformer T1 of the output circuit 200, the power supply is cut off from the primary winding side of the first transformer T1, so that the overvoltage output by the output voltage 200 can be cut off more quickly.
The embodiment of the present application further provides a power supply device, which includes the switching power supply circuit according to any of the above embodiments, because the power supply device of the present embodiment includes the switching power supply circuit according to any of the above embodiments, the power supply device of the present embodiment at least includes the corresponding advantages of the switching power supply circuit according to any of the above embodiments.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.
Claims (6)
1. A switch power supply circuit is characterized by comprising a power supply circuit and an overvoltage protection circuit,
the overvoltage protection circuit comprises:
the voltage detection component is configured to receive a detection voltage output by the power circuit and output a first conduction signal according to the detection voltage;
a first switch component connected with the voltage detection component and configured to output a third on signal when the first on signal or the second on signal is input, and output a cut-off signal according to the first voltage to control the power circuit to stop converting the input voltage into the output voltage when the second on signal is input; and
a second switching element connected to the first switching element and configured to output the second turn-on signal and the first voltage according to the detection voltage when the third turn-on signal is input, and maintain the output of the second turn-on signal and the first voltage according to an internal power voltage;
wherein the detection voltage and the output voltage are positively correlated;
the first switch component comprises a first field effect transistor and a first resistor;
a base electrode of the first field effect transistor is connected with a first end of the first resistor and is connected to a first on signal/second on signal input end of the first switch component, an emitting electrode of the first field effect transistor is connected with a second end of the first resistor and is connected to a cut-off signal output end of the first switch component, and a collector electrode of the first field effect transistor is connected to a third on signal output end of the first switch component and a first voltage input end of the first switch component;
the first switch assembly further comprises a first capacitor;
a first end of the first capacitor is connected to a first on signal/second on signal input end of the first switch component, and a second end of the first capacitor is connected to an off signal output end of the first switch component;
the second switch component comprises a second field effect transistor, a second resistor, a third resistor and a second capacitor;
a base electrode of the second field effect transistor, a first end of the second capacitor and a first end of the third resistor are connected in common and are connected to a third on-signal input end of the second switch component and a first voltage output end of the second switch component, an emitter electrode of the second field effect transistor, a second end of the second capacitor, a first end of the second resistor and a second end of the third resistor are connected in common, a collector electrode of the second field effect transistor is connected to a second on-signal output end of the second switch component, and a second end of the second resistor is connected to a detection voltage/internal power supply voltage input end of the second switch component;
the power supply circuit comprises a control circuit, an output circuit and a feedback circuit;
the control circuit is respectively connected with the output circuit, the feedback circuit and the overvoltage protection circuit and is configured to stop outputting pulse signals according to the cut-off signal and regulate the pulse signals according to the feedback signal;
the output circuit configured to output the internal power supply voltage in accordance with the input voltage, convert the input voltage into the detection voltage and the output voltage in accordance with the pulse signal when the pulse signal is input, and stop outputting the detection voltage and the output voltage when the pulse signal is stopped from being input;
the feedback circuit is configured to generate the feedback signal according to the output voltage.
2. The switching power supply circuit according to claim 1, wherein the output circuit includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a first diode, a second diode, a third diode, a first transformer, and a second transformer;
the first end of the sixth capacitor, the first end of the seventh resistor and the first end of the primary winding of the first transformer are connected in common and connected to the input voltage input end of the output circuit, the second end of the seventh resistor is connected with the first end of the sixth resistor, the second end of the sixth resistor and the first end of the fourth capacitor are connected and connected to the internal power supply voltage output end of the output circuit, the second end of the primary winding of the first transformer is connected to the pulse signal input end of the output circuit, the first end of the fifth resistor is connected with the first end of the third capacitor and connected to the detection voltage output end of the output circuit, the second end of the fifth resistor is connected with the negative electrode of the first diode, and the positive electrode of the first diode is connected with the first end of the secondary winding of the second transformer, the first end of the primary winding of the second transformer, the first end of the fifth capacitor, the cathode of the second diode, the cathode of the third diode and the first end of the eighth resistor are connected in common, the second end of the fifth capacitor is connected with the first end of the fourth resistor, the second end of the fourth resistor, the anode of the second diode and the first end of the secondary winding of the first transformer are connected in common, the second end of the eighth resistor is connected with the first end of the seventh capacitor, the second end of the primary winding of the second transformer, the first end of the eighth capacitor and the first end of the ninth resistor are connected in common and connected to the output voltage output end of the output circuit, the second end of the secondary winding of the second transformer, the second end of the third capacitor, the second end of the fourth capacitor and the second end of the sixth capacitor are all connected with the first power ground, and the second end of the seventh capacitor, the second end of the eighth capacitor, the second end of the ninth resistor, the anode of the third diode and the second end of the secondary winding of the first transformer are all connected with a second power ground.
3. The switching power supply circuit according to claim 1, wherein the feedback circuit comprises a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a ninth capacitor, an optocoupler and a controllable precision regulator;
the first end of the tenth resistor and the first end of the eleventh resistor are connected and connected to the output voltage input end of the feedback circuit, the second end of the tenth resistor, the first end of the twelfth resistor and the positive electrode of the optocoupler are connected in common, the second end of the eleventh resistor, the first end of the ninth capacitor, the first end of the fourteenth resistor and the enabling end of the controllable precise voltage stabilizing source are connected in common, the second end of the twelfth resistor, the negative electrode of the optocoupler, the first end of the thirteenth resistor and the negative electrode of the controllable precise voltage stabilizing source are connected in common, the second end of the thirteenth resistor and the second end of the ninth capacitor are connected, the collector of the optocoupler is connected to the feedback signal output end of the feedback circuit, the emitter of the optocoupler is connected with the first power ground, and the second end of the fourteenth resistor and the positive electrode of the controllable precise voltage stabilizing source are both connected with the second power ground.
4. The switching power supply circuit according to claim 1, wherein the control circuit includes a pulse chip, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, and a third field effect transistor;
the output end of the pulse chip is connected with the first end of the eighteenth resistor, the sampling end of the pulse chip, the first end of the twelfth capacitor and the first end of the nineteenth resistor are connected in common, the voltage feedback end of the pulse chip, the first end of the fifteenth resistor, the first end of the sixteenth resistor and the first end of the tenth capacitor are connected in common, the compensation end of the pulse chip and the second end of the fifteenth resistor are connected and connected to the feedback signal input end of the control circuit, the power end of the pulse chip is connected to the internal power voltage input end of the control circuit, the oscillation frequency end of the pulse chip, the second end of the sixteenth resistor and the first end of the eleventh capacitor are connected in common, the second end of the eighteenth resistor, the gate of the third field effect transistor and the first end of the twentieth resistor are connected in common, the first end of the seventeenth resistor, the second end of the nineteenth resistor, the second end of the twentieth resistor and the source of the third field effect transistor are connected in common, the drain of the third field effect transistor is connected to the pulse signal output end of the control circuit, the pulse chip, the second end of the seventeenth resistor, the second end of the power resistor and the eleventh capacitor are connected with the ground.
5. The switching power supply circuit according to claim 1, wherein the voltage detection component comprises a zener diode;
the cathode of the voltage stabilizing diode is connected to the detection voltage input end of the voltage detection assembly, and the anode of the voltage stabilizing diode is connected to the first conduction signal output end of the voltage detection assembly.
6. A power supply device characterized by comprising the switching power supply circuit according to any one of claims 1 to 5.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202011445461.1A CN112701662B (en) | 2020-12-11 | 2020-12-11 | Overvoltage protection circuit, switching power supply circuit, and power supply device |
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| CN202011445461.1A CN112701662B (en) | 2020-12-11 | 2020-12-11 | Overvoltage protection circuit, switching power supply circuit, and power supply device |
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| CN112701662A CN112701662A (en) | 2021-04-23 |
| CN112701662B true CN112701662B (en) | 2023-02-21 |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2800617Y (en) * | 2005-05-16 | 2006-07-26 | 崇贸科技股份有限公司 | Over-voltage protector |
| CN101083433A (en) * | 2006-06-01 | 2007-12-05 | 株式会社理光 | Switch electric source device |
| CN203326555U (en) * | 2013-07-23 | 2013-12-04 | 惠州市德赛西威汽车电子有限公司 | Power supply overvoltage protection circuit of electronic product port |
| CN209265382U (en) * | 2018-12-21 | 2019-08-16 | Tcl通力电子（惠州）有限公司 | Protect circuit and electronic equipment |
| CN111740381A (en) * | 2020-07-10 | 2020-10-02 | 广东美芝制冷设备有限公司 | Switching power supply circuit, air conditioning equipment and refrigerator |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102076144A (en) * | 2010-10-17 | 2011-05-25 | 尹文庭 | Solution to working power supply and power of two-wire-system electronic switch |
-
2020
- 2020-12-11 CN CN202011445461.1A patent/CN112701662B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2800617Y (en) * | 2005-05-16 | 2006-07-26 | 崇贸科技股份有限公司 | Over-voltage protector |
| CN101083433A (en) * | 2006-06-01 | 2007-12-05 | 株式会社理光 | Switch electric source device |
| CN203326555U (en) * | 2013-07-23 | 2013-12-04 | 惠州市德赛西威汽车电子有限公司 | Power supply overvoltage protection circuit of electronic product port |
| CN209265382U (en) * | 2018-12-21 | 2019-08-16 | Tcl通力电子（惠州）有限公司 | Protect circuit and electronic equipment |
| CN111740381A (en) * | 2020-07-10 | 2020-10-02 | 广东美芝制冷设备有限公司 | Switching power supply circuit, air conditioning equipment and refrigerator |
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