CN117254694A - Power supply circuit, LED power supply and output method of power supply circuit - Google Patents
Power supply circuit, LED power supply and output method of power supply circuit Download PDFInfo
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- CN117254694A CN117254694A CN202210657625.XA CN202210657625A CN117254694A CN 117254694 A CN117254694 A CN 117254694A CN 202210657625 A CN202210657625 A CN 202210657625A CN 117254694 A CN117254694 A CN 117254694A
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- 238000000034 method Methods 0.000 title claims abstract description 15
- 238000002955 isolation Methods 0.000 claims abstract description 120
- 238000006243 chemical reaction Methods 0.000 claims abstract description 101
- 238000001514 detection method Methods 0.000 claims abstract description 86
- 230000008054 signal transmission Effects 0.000 claims description 15
- 230000005669 field effect Effects 0.000 claims description 14
- 238000010586 diagram Methods 0.000 description 8
- 230000003287 optical effect Effects 0.000 description 8
- 230000002159 abnormal effect Effects 0.000 description 5
- 230000009471 action Effects 0.000 description 5
- 238000004891 communication Methods 0.000 description 5
- 238000001914 filtration Methods 0.000 description 5
- 230000003111 delayed effect Effects 0.000 description 4
- 230000008901 benefit Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
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Classifications
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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
-
- 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
-
- 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
- H02M1/32—Means for protecting converters other than automatic disconnection
-
- 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
- H02M1/36—Means for starting or stopping converters
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
- H05B45/3725—Switched mode power supply [SMPS]
- H05B45/382—Switched mode power supply [SMPS] with galvanic isolation between input and output
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
- H05B45/3725—Switched mode power supply [SMPS]
- H05B45/392—Switched mode power supply [SMPS] wherein the LEDs are placed as freewheeling diodes at the secondary side of an isolation transformer
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
- H05B45/59—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits for reducing or suppressing flicker or glow effects
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention relates to the technical field of power supplies, in particular to a power supply circuit, an LED power supply and an output method of the power supply circuit. The power supply circuit comprises an isolation conversion circuit, wherein the primary side of the isolation conversion circuit is connected with a power supply end, and the secondary side of the isolation conversion circuit is connected with a load end; the detection control circuit is respectively connected with the power end and the isolation conversion circuit, receives state signals of the primary side of the power end and the isolation conversion circuit and state signals of the secondary side of the isolation conversion circuit, and outputs control signals; the switch circuit is connected between the secondary side of the isolation conversion circuit and the load end, is connected with the detection control circuit and controls the on or off of the switch circuit according to a control signal output by the detection control circuit.
Description
Technical Field
The invention relates to the technical field of power supplies, in particular to a power supply circuit, an LED power supply and an output method of the power supply circuit.
Background
In the prior art, the basic structure of the power supply circuit of most of the larger power electric appliances, such as the lighting lamp with power larger than 25W, is shown in fig. 1: input (leftmost in the figure) -input filter loop-PF correction loop-isolation conversion loop-output filter loop-output (rightmost in the figure). The external power supply flows in from the input end, is subjected to filtering and correction, is subjected to safety isolation and energy conversion by the isolation conversion circuit, is converted into a specific output voltage, and flows out from the output end after the output voltage is filtered again to supply power to an external load (such as a lighting lamp).
In the prior art, in order to realize the quick turn-off of the power supply circuit, the output control is performed by the circuit shown in fig. 2, fig. 2 is a schematic diagram of the power supply circuit of the prior patent CN215452777U, wherein the power supply circuit is an input end AC-EMC filter circuit-PFC correction circuit-BUCK circuit-output rectifying filter-output interference signal filter-quick on-off circuit-output end (i.e. LED lamp, output load end, lead-out track, etc.). When the input end AC of the power supply circuit is turned off, the output of the power supply circuit is turned off through the quick on-off electric line, but the power supply circuit cannot stop working immediately due to the fact that the electrolytic capacitor is arranged in the power supply, and the quick on-off electric line still has voltage to keep.
In the above-described scheme, when the current of the external power supply flows into the input terminal, the power supply circuit starts to operate, and outputs a voltage to the external load; however, due to the structure of the circuit, particularly the arrangement of the isolation circuit, a certain delay exists between the waveform of the input voltage of the input end AC and the waveform of the output voltage of the output end, namely the start-up delay; the output voltage varies with the output load in the start-up delay time, which may cause abnormal operation of the load. For example: when the subsequent load is a lighting device, a problem of flashing after starting up is caused. In summary, the power supply circuit in the prior art can only realize the rapid power-off of the output end when the input end AC is powered off; and the stable and rapid conduction of the output end of the power supply circuit cannot be effectively realized.
Disclosure of Invention
In view of the above problems, the present invention provides a power supply circuit, an LED power supply, and an output method of the power supply circuit. The power supply circuit provided by the invention can comprehensively control the on-off of the output end of the power supply circuit according to the input voltage and the state signal of the isolation conversion circuit, avoid the condition that the voltage of the load end is abnormal when the power supply circuit is started, and further realize the communication function through the signals and control the working mode of the back-end load.
In the technical scheme of the invention, the power supply circuit comprises an isolation conversion circuit, wherein the primary side of the isolation conversion circuit is connected with a power supply end, and the secondary side of the isolation conversion circuit is connected with a load end, namely, the input voltage of an external power supply is input into the power supply circuit through the power supply end and is output into a subsequent load circuit through the load end after being isolated and converted by the isolation conversion circuit; the detection control circuit is respectively connected with the power supply end and the isolation conversion circuit, receives signals of the power supply end, namely input voltage signals and state signals of a primary side and a secondary side of the isolation conversion circuit, and outputs control signals to the switch circuit according to the state signals; the switch circuit is connected between the secondary side of the isolation conversion circuit and the load end, is connected with the detection control circuit and controls the on or off of the switch circuit according to a control signal output by the detection control circuit.
According to the technical scheme of the invention, when the input voltage of the external power supply is input into the power supply circuit through the power supply end, the power supply circuit is started, the waveform of the input voltage is high level, the state signals of the primary side and the secondary side of the isolation conversion circuit are still low level, namely, the power supply circuit does not output voltage to the load end at the moment of starting the power supply circuit. After a period of starting delay time, the state signal of the primary/secondary side circuit is converted into a high level, the isolation signal circuit starts to work, the input voltage signal and the primary side state signal are simultaneously transmitted to the secondary side and act with the secondary side state signal to provide the high level for the switch circuit, and at the moment, the switch circuit is conducted, and the power circuit outputs voltage to the load end.
Through the circuit, the detection control circuit can combine the input voltage signal and the primary side and secondary side state signals of the isolation conversion circuit to comprehensively judge and output the control signal. When the input voltage signal and the primary side and secondary side state signals of the isolation conversion circuit are in normal working states such as high level, the switch circuit is conducted, and the power circuit outputs voltage to the load end. In the starting delay period, the isolation conversion circuit does not enter a normal working state, and the power supply circuit does not output voltage to the load end at the moment that the output voltage is unstable when starting is delayed is avoided, so that stable output of the voltage output to the load end by the power supply circuit is realized while high-efficiency on-off of the power supply circuit is ensured.
Preferably, in the technical scheme of the invention, the detection control circuit comprises a primary side detection circuit which is respectively connected with the primary sides of the power end and the isolation conversion circuit and receives state signals of the primary sides of the power end and the isolation conversion circuit; the secondary side detection circuit is connected with the secondary side of the isolation conversion circuit and receives a state signal of the secondary side of the isolation conversion circuit; the isolation signal transmission circuit is arranged between the primary side detection circuit and the secondary side detection circuit and isolates signals of the primary side detection circuit and the secondary side detection circuit.
According to the technical scheme of the invention, the primary side and the secondary side are isolated through the isolating signal transmission circuit, and meanwhile, the primary side detection signal and the control signal of the switch circuit are isolated, so that safety isolation is provided for the back-end circuit.
Further, in the technical scheme of the invention, the detection control circuit generates control signals according to signals of the primary side detection circuit and the secondary side detection circuit.
According to the technical scheme of the invention, the primary side detection circuit detects the primary side state signal of the isolation conversion circuit while receiving the input voltage signal of the power supply end, so that the complete state information of the primary side of the isolation conversion circuit can be ensured to be transmitted to the secondary side. The primary side detection circuit is connected with the isolation signal transmission circuit and transmits a primary side detection signal to the secondary side detection circuit. The secondary side detection circuit is connected with the secondary side of the isolation conversion circuit, and the detection control circuit generates a control signal according to detection signals of the primary side detection circuit and the secondary side detection circuit. The secondary side receives the voltage converted by the isolation conversion circuit and detects the secondary side state signal of the isolation conversion circuit, so that the waveform of the output voltage is ensured not to be distorted, the output voltage signal of the load end can follow the input voltage signal and the working state of the system, and the basic communication function is realized.
Furthermore, in the technical scheme of the invention, the switching circuit controls the working mode of the circuit at the load end according to the control signal. The output of the power supply circuit can realize quick on-off, so that the quick on-off function can be utilized, and the switching action of the input end of the power supply circuit is used as a control signal to control the working mode of the load end circuit of the power supply circuit.
Preferably, in the technical solution of the present invention, the isolated signal transmission circuit in the power supply circuit is an optocoupler. The optical coupler is a component for transmitting electric signals by taking optical signals as media, the signals at the input end and the output end of the optical coupler can be well isolated, and the optical coupler has signal transmission unidirectionality, good electric insulation capacity and anti-interference capacity, and can realize effective primary side and secondary side signal isolation functions.
Preferably, in the technical scheme of the present invention, the power supply circuit further includes an input filter circuit connected between the power supply terminal and the primary side of the isolation conversion circuit, for filtering noise in the input voltage of the external power supply, so that a stable voltage is input into the primary side of the isolation conversion circuit; and the output filter circuit is connected between the secondary side of the isolation conversion circuit and the load end and is used for filtering noise in the output voltage of the secondary side so as to stabilize the output voltage of the power supply circuit.
Further, in the technical scheme of the invention, the power supply circuit further comprises a power factor correction circuit connected between the input filter circuit and the primary side of the isolation conversion circuit.
According to the technical scheme of the invention, the external power supply applies the input voltage to the power supply circuit through the input end, the input voltage forms a stable input voltage signal after noise is filtered by the input filter circuit, and the integral active power of the power supply circuit is improved through the power factor correction circuit, so that the output benefit of the power supply circuit is improved.
Preferably, in the technical scheme of the invention, the switch circuit in the power supply circuit comprises a field effect transistor, and the gate of the field effect transistor is connected with the detection control circuit and receives the control signal output by the detection control circuit.
According to the technical scheme of the invention, the field effect transistor in the switching circuit is used as a main switch, so that the high-speed on/off of the power supply circuit can be realized while the complete transmission of the input voltage and the working state is realized. And the field effect tube has high stability and long service life, and can realize high-efficiency signal conversion of a system only by extremely small driving current without connecting a special driving circuit.
In the technical scheme of the invention, the LED lamp comprises the power supply circuit, the LED lamp can be started and shut down rapidly through the power supply circuit, the problem of lamplight flickering caused by unstable output voltage when the power supply circuit is started and delayed can be avoided, and the damage of the unstable output voltage to the LED load circuit is avoided.
In the technical scheme of the invention, the invention also provides an output method of the power supply circuit, and the power supply circuit is applied, and the output method comprises the following steps of
A signal detection step, wherein the detection control circuit receives state signals of a power supply end, a primary side of the isolation conversion circuit and a secondary side of the isolation conversion circuit, and if the state signals of the power supply end, the primary side of the isolation conversion circuit and the secondary side of the isolation conversion circuit are all in a normal state, a conduction control signal is output;
and outputting, namely receiving the conduction control signal, conducting the switching circuit, and outputting the voltage to the load end by the power circuit.
According to the technical scheme of the invention, the output method of the power supply circuit is based on the input voltage state and the state signals of the primary side of the isolation conversion circuit and the secondary side of the isolation conversion circuit to control the output on-off of the power supply voltage, so that the power supply circuit can conduct and supply power to the load end only when the input voltage of the power supply circuit and the voltage of the isolation conversion circuit are in normal states, and the condition that the voltage of the load end is abnormal when the power supply circuit is started is avoided. Furthermore, the output of the power circuit can realize quick on-off, so that the quick on-off function can be utilized, and the switching action of the input end of the power circuit is used as a control signal to control the working mode of the load end circuit of the power circuit.
Drawings
FIG. 1 is a schematic diagram of a prior art power supply circuit;
FIG. 2 is a schematic diagram of another prior art power supply circuit;
FIG. 3 is a schematic waveform diagram of the power circuit of FIG. 2;
FIG. 4 is a schematic diagram of a power supply circuit provided in an embodiment of the invention;
FIG. 5 is a schematic waveform diagram of the power circuit of FIG. 4;
FIG. 6 is a schematic diagram of a preferred power supply circuit provided in an embodiment of the present invention;
fig. 7 is a flowchart of an output method of a power supply circuit provided in an embodiment of the present invention.
Reference numerals illustrate: the device comprises a 1-isolation conversion circuit, a 2-detection control circuit, a 21-primary side detection circuit, a 22-secondary side detection circuit, a 23-isolation signal transmission circuit, a 231-optocoupler, a 3-switch circuit, a 4-input filter circuit, a 5-output filter circuit, a 6-power factor correction circuit, a power supply end IN, a load end OUT and a field effect transistor Q.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art without making any inventive effort, are intended to be within the scope of the present invention.
In the prior art as shown in fig. 2, the power supply circuit in the power supply circuit is an input end AC-EMC filter circuit-PFC correction circuit-BUCK circuit-output rectifying filter-output interference signal filter-fast on-off circuit-output end (i.e. LED lamp, output load end, lead-out track, etc.). The input end AC, the EMC filter circuit, the PFC correction circuit and the BUCK step-down circuit are primary side circuits which are input circuits of the transformer, the output rectifying filter, the output interference signal filter, the quick power-on and power-off circuit and the output end which is a secondary side circuit which is an output circuit of the transformer. The current of the external power supply enters the primary side circuit through the input end AC, is regulated by the transformer and is output to the external load through the secondary side circuit. The output on-off of the power supply circuit is controlled by the quick on-off electric line, namely, when the quick on-off electric line is turned off, the whole power supply circuit can be turned off, and the power supply of the load end is stopped. The on-off of the quick on-off circuit is controlled by a detection signal sent by a signal feedback and control signal output circuit from an input electric signal detection circuit, and the input electric signal detection circuit is connected with an input end AC and detects a state signal of the input end AC.
However, due to the structure of the power supply circuit, especially the arrangement of the isolation circuit, i.e. the transformer, when the input terminal AC starts/stops supplying power, a certain delay exists between the waveforms of the voltages at the two ends of the isolation circuit, i.e. the start-up delay. The voltage waveform of the power supply circuit is shown in fig. 3. When the input terminal AC is started quickly after being closed, t 01 The power supply circuit starts at the moment and inputs a voltage signal V in At high level, the switching state signal V of the isolation circuit is due to the presence of the start-up delay time 1 And input voltage signal V in Has a delay between the waveforms of t 01 Switching state signal V of time isolation circuit 1 Is low level but outputs a switching signal V 2 And input voltage signal V in Synchronous high level, triggering the on-off of the fast electric line, t 01 The power supply circuit outputs voltage to the external load at the moment, and the output voltage signal is V out The method comprises the steps of carrying out a first treatment on the surface of the But the output voltage will follow in the turn-on delay timeThe load side changes, which shows a tendency to drop before restart, and the output voltage value may be unstable during the start-up delay time and its subsequent time. In the start-up delay time, the isolation circuit is not in a normal working state, so that abnormal actions of a load-side circuit or a device may be caused. And also makes the back-end circuit unable to accurately detect the quick closing/starting action of the input AC.
Fig. 4 is a schematic diagram of a power supply circuit provided in an embodiment of the invention.
As shown in fig. 4, in an embodiment of the present invention, there is provided a power supply circuit including an isolation conversion circuit 1, a detection control circuit 2, and a switching circuit 3.
The primary side (left side IN the figure) of the isolation conversion circuit 1 is connected with a power supply end IN, the secondary side (right side IN the figure) is connected with a switch circuit 3, the switch circuit 3 is connected with a load end OUT, namely, the input voltage of an external power supply is input into the power supply circuit through the power supply end IN, and is output into a subsequent load circuit through the switch circuit 3 after isolation conversion of the isolation conversion circuit 1;
the detection control circuit 2 is connected with the power supply terminal IN and the isolation conversion circuit 1 respectively, and receives an input voltage signal V which is a signal of the power supply terminal IN in A primary side state signal of the isolation conversion circuit 1 and a secondary side state signal of the isolation conversion circuit 1, and outputs a control signal to the switch circuit 3 according to the state signals;
the switching circuit 3 is connected between the secondary side (right side in the figure) of the isolation converting circuit 1 and the load terminal OUT, and the switching circuit 3 is connected to the detection control circuit 2, and the switching circuit 3 controls on or off of the switching circuit 3 according to a control signal output from the detection control circuit 2.
The voltage waveform of the power supply circuit is shown in fig. 5. As shown IN fig. 5, when the input voltage of the external power is input into the power circuit via the power terminal IN, t 0 The power supply circuit starts at the moment and inputs a voltage signal V in The primary side state signal and the secondary side state signal of the isolation conversion circuit 1 are synchronous and are the conversion state signal V 1 Switching state signal V 1 Delayed from the input voltage signalV in At low level, output switch signal V 2 In synchronization with the input voltage signal V in The switch circuit 3 integrates the signals and is turned on only when the signals are in a normal state, namely, the high level; i.e. t 0 The time switch circuit 3 is not turned on, and the power supply circuit does not output a voltage to the load terminal OUT. After a delay time, the conversion state signal V of the conversion circuit 1 is isolated 1 And input voltage signal V in Synchronization, i.e. from t 1 The isolation switching circuit 1 can normally and stably output voltage and input a voltage signal V in Transition state signal V 1 And output a switching signal V 2 All are high level, at this time, the switching circuit 3 is turned on, and the power supply circuit outputs a voltage to the load terminal OUT.
By the above circuit, the detection control circuit 2 can combine the input voltage signal V in And the primary side state signal and the secondary side state signal of the isolation conversion circuit 1 are comprehensively judged and output control signals. At the input voltage signal V in The primary side state signal of the isolation conversion circuit 1 and the secondary side state signal of the isolation conversion circuit 1 are all IN high level, namely, when the power supply end IN of the power supply circuit and the primary side and the secondary side of the isolation conversion circuit 1 are IN normal working states, the switch circuit 3 is conducted, and the power supply circuit outputs voltage to the load end OUT. And at the start-up delay time t 0 -t 1 At the moment, the switching state signal V of the switching circuit 1 is isolated 1 The power supply circuit outputs no voltage to the load end OUT at the moment when the power supply circuit is in low level, so that the moment that the output voltage is unstable during starting is avoided, and stable output of the voltage output by the power supply circuit to the load end OUT is realized while high-efficiency on-off of the power supply circuit is ensured.
IN the embodiment of the invention, an input filter circuit 4 is arranged between a power supply end IN of the power supply circuit and a primary side of the isolation conversion circuit 1, namely, the primary side, and is used for filtering noise IN an input voltage of an external power supply so as to enable a stable voltage to be input into the primary side of the isolation conversion circuit 1; an output filter circuit 5 is disposed between the secondary side of the isolation conversion circuit 1 and the load end OUT of the power circuit, that is, on the secondary side, and is connected between the secondary side of the isolation conversion circuit 1 and the load end OUT, and is used for filtering noise in the output voltage of the secondary side, so that the output voltage of the power circuit is stable.
It should be noted that, in the present embodiment, the input filter circuit 4 and the output filter circuit 5 are each in a module form, and in practical application, the input filter circuit 4 and the output filter circuit 5 may be configured by a LC filter, an RC filter, a filter formed by special elements, or the like, which is not limited herein.
IN the embodiment of the invention, the power circuit further comprises a power factor correction circuit 6 connected between the input filter circuit 4 and the primary side of the isolation conversion circuit 1, the external power supply applies the input voltage to the power circuit through the power terminal IN, and the input voltage forms a stable input voltage signal after noise is filtered by the input filter circuit 4, and the power factor correction circuit 6 improves the overall active power of the power circuit and the output benefit of the power circuit.
Preferably, IN the embodiment of the present invention, the detection control circuit 2 of the power supply circuit includes a primary side detection circuit 21, a secondary side detection circuit 22 and an isolation signal transmission circuit 23, wherein the primary side detection circuit 21 is respectively connected to the primary side of the power supply terminal IN and the isolation conversion circuit 1, and receives the input voltage signal V of the power supply terminal IN in And isolating the primary state signal of the conversion circuit 1. The secondary side detection circuit 22 is connected to the secondary side of the isolation converter circuit 1, and receives a secondary side state signal of the isolation converter circuit 1. The isolation signal transmission circuit 23 is provided between the primary side detection circuit 21 and the secondary side detection circuit 22, and isolates the electrical signals of the primary side detection circuit 21 and the secondary side detection circuit 22. The primary side and secondary side circuits are isolated by the isolation signal transmission circuit 23, and the primary side detection signal and the control signal of the switch circuit 3 are isolated at the same time, so that safety isolation is provided for the back-end circuit.
Preferably, in the embodiment of the present invention, the detection control circuit 2 generates the control signal based on the primary side state signal of the primary side detection circuit 21 and the secondary side state signal of the secondary side detection circuit 22. Wherein the primary side detection circuit 21 receives the input voltage signal V at the power supply terminal IN in At the same time as the primary side status signal of the isolated switching circuit 1 is detected,it is ensured that the complete state information of the primary side of the isolated switching circuit 1 is transferred to the secondary side. The primary side detection circuit 21 is connected to the isolation signal transmission circuit 23, and transmits a signal detected by the primary side to the secondary side detection circuit 22. The secondary side detection circuit 22 of the detection control circuit 2 is connected to the secondary side of the isolation switch circuit 1, and the detection control circuit 2 generates a control signal based on the secondary side state signal of the isolation switch circuit 1 and the signal detected by the primary side. The secondary side receives the voltage converted by the isolation conversion circuit 1 and detects the secondary side state signal of the isolation conversion circuit 1, thereby ensuring that the output voltage waveform is not distorted and the output voltage signal V of the load end OUT out Capable of following an input voltage signal V in And the working state of the system, thereby realizing the basic communication function.
Further, in the embodiment of the present invention, by the implementation of the above-described basic communication function, the switching circuit 3 in the power supply circuit controls the operation mode of the circuit of the load terminal OUT according to the control signal.
Because of the power supply circuit in the embodiment, rapid on-off control can be realized, and the output waveform of the load terminal OUT is not affected by the load circuit connected with the load terminal OUT when the power supply circuit is rapidly turned on and off. As shown IN fig. 5, the power terminal IN of the power circuit can be rapidly turned on/off IN a short time, and can be clearly shown IN waveforms. Therefore, the on-off times of the power supply terminal IN of the power supply circuit IN a certain time can be used as a control signal to control the action of the load circuit connected with the load terminal OUT.
For example, taking 1 second as a period, the load connected to the load terminal OUT is an LED lamp. The power end IN of the power circuit is started/closed for 1 time IN one period, namely 1s, and the brightness of the LED lamp is 100%; the power end IN of the power circuit is started/closed for 2 times within one period, namely 1s, and the brightness of the LED lamp is 70%; the power supply end IN of the power supply circuit is started/closed 3 times within one period, namely 1s, the brightness of the LED lamp is 50%, so that the working mode of the circuit connected with the load end OUT is controlled by the switch circuit 3 IN the power supply circuit according to the control signal through the basic communication function.
It should be noted that, in the embodiment of the present invention, the period time and the judgment of the control signal in each period can be adjusted according to the actual circuit structure. The load working mode controlled by the control signal is not limited to the adjustment of the brightness of the lamp, and the adjustment and control of the color, the color temperature, the flicker frequency, the preset illumination time and the like of the lamp can be performed. The circuit connected with the load end OUT is not limited to the LED lamp, and the circuit is within the protection scope of the invention as long as the action of controlling the load circuit connected with the load end OUT according to the control signal can be realized.
The operation of controlling the load circuit connected to the load terminal OUT by the control signal may be implemented by a control chip or a circuit provided in the power supply circuit, or may be implemented by a control chip, a circuit, a program, or other means provided in the connected load or externally connected thereto, which is not limited herein.
Preferably, in the embodiment of the present invention, the isolated signal transmission circuit 23 in the power supply circuit is an optocoupler 231. The optical coupler 231 is a component for transmitting an electric signal by taking an optical signal as a medium, the signals at the input end and the output end of the optical coupler 231 can be well isolated, and the signal transmission of the optical coupler 231 has unidirectionality, good electric insulation capability and anti-interference capability, and can realize effective primary side and secondary side signal isolation functions.
Specifically, as shown in fig. 6, in the embodiment of the present invention, a power supply circuit is provided, wherein the upper side is the isolation conversion circuit 1, the left side is the primary side of the isolation conversion circuit 1, and the right side is the secondary side of the isolation conversion circuit 1; the primary side detection circuits 21 of the detection control circuit 2 respectively receive the input voltage signals V of the power supply terminals IN in And isolating the primary state signal of the conversion circuit 1, the input voltage signal V of the power supply terminal IN in The primary side state signals of the isolation conversion circuit 1 are respectively applied to two pins of the input end of the isolation signal transmission circuit 23, namely the optocoupler 231, and are isolated and transmitted to the output end of the optocoupler 231, namely the secondary side detection circuit 22 of the detection control circuit 2 through the optocoupler 231; the primary side detected signal outputted from the output end of the optocoupler 231 and the secondary side state signal of the isolation conversion circuit 1 are simultaneously applied to the control end of the switch circuit 3 to control the switchThe on-off of the circuit 3 is turned off. Specifically, the switching circuit 3 includes a field effect transistor Q, where a gate of the field effect transistor Q is connected to the detection control circuit 2, and receives a control signal output by the detection control circuit 2, that is, a signal detected by a primary side of an output end of the optocoupler 231 and a secondary side state signal of the isolation conversion circuit 1, and controls on/off of the field effect transistor Q according to the control signal. Input voltage signal V at power supply terminal IN in When the primary side state signal of the isolation conversion circuit 1 and the secondary side state signal of the isolation conversion circuit 1 are both in a normal working state (high level), the gate voltage of the field effect transistor Q enables the field effect transistor Q to be conducted, namely the switch circuit 3 is conducted, so that the power supply circuit stably supplies power to the load end OUT.
The switching circuit 3 uses the field effect transistor Q as a main switch, so that the high-speed on/off of the power supply circuit can be realized while the complete transmission of the input voltage and the working state is realized. And the field effect tube has high stability and long service life, and can realize high-efficiency signal conversion of a system only by extremely small driving current without connecting a special driving circuit.
It should be noted that, in the embodiment of the present invention, the fast switching of the switching circuit 3 may also be implemented by different switching devices or circuits such as a relay, which is not limited herein.
In an embodiment of the invention, the LED lamp comprises the power supply circuit, the LED lamp can be started or shut off rapidly through the power supply circuit, the problem of lamplight flickering caused by unstable output voltage when the power supply circuit is started and delayed can be avoided, and the damage of the unstable output voltage to the LED load circuit is avoided. Similarly, the power supply circuit provided by the invention can also be applied to power supplies of other high-power loads, such as IT type circuits and the like, and is not limited herein.
As shown in fig. 7, in an embodiment of the present invention, there is also provided an output method of a power supply circuit, to which the above power supply circuit is applied, the output method including
IN the signal detection step S1, the detection control circuit 2 receives the state signals of the power supply terminal IN, the primary side of the isolation conversion circuit 1, and the secondary side of the isolation conversion circuit 1, and if the state signals of the power supply terminal IN, the primary side of the isolation conversion circuit 1, and the secondary side of the isolation conversion circuit 1 are all IN a normal state, outputs a conduction control signal;
and in the output step S2, the switch circuit 3 is turned on after receiving the on control signal, and the power supply circuit outputs voltage to the load end OUT.
The output method of the power supply circuit is based on the input voltage state and the state signals of the primary side of the isolation conversion circuit 1 and the secondary side of the isolation conversion circuit 1 to comprehensively judge so as to control the output on-off of the power supply voltage, so that the power supply circuit can conduct and supply power to the load end OUT only when the input voltage of the power supply circuit and the voltage of the isolation conversion circuit 1 are in a normal state, and the condition that the voltage of the load end OUT is abnormal when the power supply circuit is started is avoided.
The technical solution of the present invention has been described so far with reference to the accompanying drawings. However, it will be readily appreciated by those skilled in the art that the scope of the present invention is not limited to the above-described specific embodiments. Equivalent modifications and substitutions for related technical features may be made by those skilled in the art without departing from the principles of the present invention, and such modifications and substitutions will fall within the scope of the present invention.
Claims (10)
1. A power supply circuit, comprising
The primary side of the isolation conversion circuit is connected with the power supply end, and the secondary side of the isolation conversion circuit is connected with the load end;
the detection control circuit is respectively connected with the power supply end and the isolation conversion circuit, receives state signals of the power supply end, the primary side of the isolation conversion circuit and the secondary side of the isolation conversion circuit, and outputs control signals;
the switch circuit is connected between the secondary side of the isolation conversion circuit and the load end, and is connected with the detection control circuit, and the switch circuit controls the on or off of the switch circuit according to the control signal output by the detection control circuit.
2. The power supply circuit of claim 1, wherein the detection control circuit comprises
The primary side detection circuit is respectively connected with the power supply end and the primary side of the isolation conversion circuit and receives state signals of the power supply end and the primary side of the isolation conversion circuit;
the secondary side detection circuit is connected with the secondary side of the isolation conversion circuit and receives a state signal of the secondary side of the isolation conversion circuit;
and the isolation signal transmission circuit is arranged between the primary side detection circuit and the secondary side detection circuit and isolates signals of the primary side detection circuit and the secondary side detection circuit.
3. The power supply circuit of claim 2, wherein the detection control circuit generates the control signal based on signals of the primary side detection circuit and the secondary side detection circuit.
4. A power supply circuit as claimed in claim 3, characterized in that the switching circuit controls the operating mode of the circuit at the load side in dependence on the control signal.
5. The power supply circuit of claim 4, wherein the isolated signal transmission circuit is an optocoupler.
6. The power supply circuit of claim 5, further comprising
The input filter circuit is connected between the power end and the primary side of the isolation conversion circuit;
and the output filter circuit is connected between the secondary side of the isolation conversion circuit and the load end.
7. The power supply circuit of claim 6, further comprising a power factor correction circuit connected between the input filter circuit and a primary side of the isolated switching circuit.
8. The power supply circuit of claim 7, wherein the switching circuit comprises a field effect transistor, a gate connection of the field effect transistor is connected to the detection control circuit, and a control signal output by the detection control circuit is received.
9. An LED luminaire characterized by comprising the power supply circuit of any one of claims 1-8.
10. A method of outputting a power supply circuit as claimed in any one of claims 1 to 8, characterized in that the method comprises
A signal detection step S1, wherein a detection control circuit receives state signals of the power supply end, the primary side of the isolation conversion circuit and the secondary side of the isolation conversion circuit, and if the state signals of the power supply end, the primary side of the isolation conversion circuit and the secondary side of the isolation conversion circuit are all in a normal state, a conduction control signal is output;
and S2, receiving the conduction control signal, conducting the switch circuit, and outputting voltage to a load end by the power supply circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210657625.XA CN117254694A (en) | 2022-06-10 | 2022-06-10 | Power supply circuit, LED power supply and output method of power supply circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210657625.XA CN117254694A (en) | 2022-06-10 | 2022-06-10 | Power supply circuit, LED power supply and output method of power supply circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117254694A true CN117254694A (en) | 2023-12-19 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210657625.XA Pending CN117254694A (en) | 2022-06-10 | 2022-06-10 | Power supply circuit, LED power supply and output method of power supply circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117254694A (en) |
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2022
- 2022-06-10 CN CN202210657625.XA patent/CN117254694A/en active Pending
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