CN111463894B - Power supply switching circuit - Google Patents
Power supply switching circuit Download PDFInfo
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- CN111463894B CN111463894B CN202010344480.9A CN202010344480A CN111463894B CN 111463894 B CN111463894 B CN 111463894B CN 202010344480 A CN202010344480 A CN 202010344480A CN 111463894 B CN111463894 B CN 111463894B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
- H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
- H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
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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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- 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
- Y02B70/30—Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
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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
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
- Y04S20/20—End-user application control systems
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
- Electronic Switches (AREA)
Abstract
The invention provides a power supply switching circuit, comprising: a first switching device configured to receive a first supply signal and output; the output end of the second switching device is connected with the output end of the first switching device, and the second switching device is configured to receive and output a second power supply signal; the control circuit is connected with the control end of the first switch device and the control end of the second switch device, and the control circuit is configured to selectively control one switch device of the first switch device and the second switch device to be in a conducting state and the other switch device to be in a cut-off state according to a comparison result of the first power supply signal and the preset power supply voltage.
Description
Technical Field
The invention relates to the technical field of low-voltage electric appliances, in particular to a power supply switching circuit.
Background
At present, the dual-power automatic switching circuit is often applied to some electronic products which need to use a backup power supply, such as the electric meter industry, the engineering control industry and the like.
The prior art can not automatically realize the switching of the main power supply and the backup power supply.
Disclosure of Invention
The present invention is directed to solving or improving at least one of the technical problems of the prior art or the related art.
To this end, the present invention provides a power switching circuit.
In view of the above, the present invention provides a power switching circuit, including: a first switching device configured to receive a first supply signal and output; a second switching device, an output end of the second switching device is connected with an output end of the first switching device, and the second switching device is configured to receive the second power supply signal and output the second power supply signal; and the control circuit is connected with the control end of the first switching device and the control end of the second switching device, and is configured to selectively control any one of the first switching device and the second switching device to be in a conducting state and the other switching device to be in a stopping state according to a comparison result of the first power supply signal and a preset power supply voltage.
The invention provides a power supply switching circuit, wherein a control circuit is connected with a control end of a first switching device and a control end of a second switching device, the control circuit is configured to control only one of the first switching device and the second switching device to be in a conducting state according to a comparison result of a first power supply signal and a preset power supply voltage, and in the process, the conducting state of the first switching device and the conducting state of the second switching device and the comparison result of the first power supply signal and the preset power supply voltage are related, so that automatic switching of a main power supply (namely the first power supply signal) and a backup power supply (namely the second power supply signal) can be realized, and the power of the position where an output end of the second switching device is connected with the output end of the first switching device can be stably output to meet the actual power supply requirement of a load.
In addition, only one of the first switch device and the second switch device is in a conducting state, so that the first power supply signal and the second power supply signal cannot be influenced mutually, if the first power supply signal flows backwards to the second power supply signal, or the second power supply signal flows backwards to the first power supply signal, and the like, the stability of the power supply switching circuit during operation is improved.
In addition, the power switching circuit in the above technical solution provided by the present invention may further have the following additional technical features:
in the above technical solution, the control circuit includes: the first control circuit is connected with the control end of the first switching device and is configured to control the on-off state of the first switching device according to the comparison result of the first power supply signal and the preset power supply voltage; and the second control circuit is connected with the first control circuit and the control end of the second switching device and is configured to control the on-off state of the second switching device according to the comparison result.
In the technical scheme, the control circuit comprises a first control circuit and a second control circuit, and the second control circuit is connected with the first control circuit, so that the first control circuit and the second control circuit can form an interlocking circuit, and further, only one of the first switch device and the second switch device is in a conducting state at the same moment, and the stability of the power supply switching circuit during operation is improved.
In any of the above technical solutions, based on that the first power supply signal is smaller than a preset power supply voltage, the first control circuit controls the first switching device to be in an off state, and the second control circuit controls the second switching device to be in an on state; or based on the first power supply signal being greater than or equal to the preset power supply voltage, the first control circuit controls the first switching device to be in a conducting state, and the second control circuit controls the second switching device to be in a disconnecting state.
In the technical scheme, when a first power supply signal is smaller than a preset power supply voltage, a first control circuit controls a first switch device to be in an off state, a second control circuit controls a second switch device to be in an on state, so that power is supplied by using a second power supply signal under the condition that the first power supply signal is insufficient, the power supply switching circuit can stably supply power to a load, meanwhile, based on the condition that the first power supply signal is larger than or equal to the preset power supply voltage, the first control circuit controls the first switch device to be in the on state, the second control circuit controls the second switch device to be in the off state, so that power is supplied by preferentially using the first power supply signal, and under the normal condition, a backup power supply is supplied by using a battery.
In any one of the above technical solutions, the first control circuit includes: the output end of the third switching device is grounded; the first switch device comprises a first optical coupler, a first input end and a second input end of the first optical coupler receive a first power supply signal, a first output end of the first optical coupler is connected with an input end of the third switch device, and a second output end of the first optical coupler is configured to output the first power supply signal; the second control circuit includes: the output end of the fourth switching device is grounded; the second switch device comprises a second optical coupler, a first input end and a second input end of the second optical coupler receive a second power supply signal, a first output end of the second optical coupler is connected with an input end of the third switch device, and a second output end of the second optical coupler is configured to output the second power supply signal; under the condition that a first input end of the first optocoupler is communicated with a first output end of the first optocoupler, a second input end of the first optocoupler is communicated with a second output end of the first optocoupler; based on the first input end of the second optocoupler and the first output end of the second optocoupler are communicated, the second input end of the second optocoupler is communicated with the second output end of the second optocoupler.
In this technical scheme, because first input end and the second input end of the first opto-coupler that first switching device includes receive first power supply signal, therefore, first switching signal can also realize supplying power to first switching device self when having the effect of the outside power supply of second input end and the second output through first switching device, and simultaneously, the first output end of first opto-coupler is connected with the input of third switching device, and the output ground of third switching device, therefore, can control the on-state of first switching device according to the on-state of third switching device, and then realize the control whether first power supply signal is exported, and the power supply control of second opto-coupler and fourth switching device is similar with the power supply relation of first opto-coupler and third switching device, no longer give unnecessary details, and the use of switching device and opto-coupler cooperation has reduced the use of control circuit and switching device power supply, be convenient for the circuit miniaturization and integration, be convenient for control cost simultaneously.
In any one of the above technical solutions, the first control circuit further includes: the first end of the first resistor receives a first power supply signal; the first end of the second resistor is connected with the second end of the first resistor, and the second end of the second resistor is grounded; the first end of the second resistor is connected with the control end of the third switching device; the control end of the third switching device controls the on-off state of the input end of the third switching device and the output end of the third switching device according to the voltage signal of the first end of the second resistor.
In the technical scheme, the first resistor and the second resistor are connected in series and grounded, and under the action of the first power supply signal, the first resistor and the second resistor have a voltage dividing effect, which is expressed in that a position where the first resistor and the second resistor are connected (namely, a first end of the second resistor) has a voltage, and the voltage corresponds to the first power supply signal, so that the voltage can be used for representing the actual condition of the first power supply signal, and the on-state control of the third switching device is realized by comparing the voltage signal with the on-state voltage of the third switching device.
In any of the above technical solutions, the method further includes: the cathode of the first diode is connected with the first output end of the first optocoupler, and the anode of the first diode is connected with the first input end of the second optocoupler; the second control circuit further includes: a first end of the third resistor receives a second power supply signal; a first end of the fourth resistor is connected with a second end of the third resistor and a first input end of the second optocoupler, and a second end of the fourth resistor is grounded; the first end of the fourth resistor is connected with the control end of the fourth switching device; the control end of the fourth switching device controls the on-off state of the input end of the fourth switching device and the output end of the fourth switching device according to the voltage signal of the anode of the first diode.
In the technical scheme, the first diode is used as a clamping diode, and based on the connection relation between the first diode and the second optocoupler, the second control circuit can be controlled according to the state of the first control circuit, so as to further realize the control of the second switch device.
In any of the above technical solutions, the method further comprises: and the second diode is connected between the first end of the fourth resistor and the control end of the fourth switching device in series, the anode of the second diode is connected with the first end of the fourth resistor, and the cathode of the second diode is connected with the control end of the fourth switching device.
In the technical scheme, the second diode is arranged, the characteristic that the diode is conducted to have conduction voltage drop is utilized, the trigger voltage value of the control end of the fourth switching device is improved, the possibility that the fourth switching device is triggered by mistake is reduced, and the stability of the power supply switching circuit is further improved.
In any of the above technical solutions, the method further includes: a fifth resistor, a first end of the fifth resistor being connected to the first input end of the first optocoupler, and a second end of the fifth resistor being configured to receive the first supply signal.
In the technical scheme, the set fifth resistor, the photodiode in the first optocoupler and the third switch device form a series connection relationship, a preset power supply voltage setting process is realized by controlling the voltage of the cathode position of the diode, and power supply switching is conveniently carried out according to actual power supply requirements.
In any of the above technical solutions, the fifth resistor is an adjustable resistor.
In the technical scheme, the adjustable resistor is convenient to adjust according to the actual requirement of a user, and the power supply switching circuit can adapt to various use environments.
In any of the above technical solutions, the method further includes: and the input end of the voltage conversion circuit is connected with the output end of the first switching device.
In the technical scheme, the power supply switching circuit is connected with the output end of the first switching device so as to carry out voltage conversion on the received power supply signal and output the power supply signal, so that the power supply requirements of different loads are met, and the power supply switching circuit can adapt to various power utilization requirements.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 shows a circuit schematic of a power switching circuit according to one embodiment of the invention;
FIG. 2 shows a circuit schematic of a power switching circuit according to one embodiment of the invention;
FIG. 3 shows a circuit schematic of a power switching circuit according to one embodiment of the invention;
FIG. 4 shows a circuit schematic of a voltage conversion circuit according to one embodiment of the invention.
Wherein, the correspondence between the reference numbers and the component names in fig. 1 to 3 is:
102 a first switch device, 104 a second switch device, 106 a control circuit, 1062 a first control circuit, 1064 a second control circuit, 108 a voltage conversion circuit, a phothomos 1 first optical coupler, a phothomos 2 second optical coupler, a Q1 third switch device, a Q2 fourth switch device, an R1 first resistor, an R2 second resistor, an R3 third resistor, an R4 fourth resistor, an R5 fifth resistor, a D1 first diode, and a D2 second diode.
Detailed Description
So that the manner in which the above recited aspects, features and advantages of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.
Example one
The present invention provides a power switching circuit, as shown in fig. 1, including: a first switching device 102, the first switching device 102 configured to receive a first supply signal and output; a second switching device 104, an output terminal of the second switching device 104 is connected to an output terminal of the first switching device 102, and the second switching device 104 is configured to receive the second power supply signal and output the second power supply signal; a control circuit connected to the control terminal of the first switching device 102 and the control terminal of the second switching device 104, the control circuit being configured to control the first switching device 102 to be in a conducting state and the second switching device 104 to be in a blocking state according to a comparison result of the first power supply signal and a preset power supply voltage; or the first switching device 102 is in an off state and the second switching device 104 is in an on state.
The invention provides a power supply switching circuit, wherein a control circuit 106 is connected with a control end of a first switch device 102 and a control end of a second switch device 104, the control circuit 106 is configured to control only one of the first switch device 102 and the second switch device 104 to be in a conducting state according to a comparison result of a first power supply signal and a preset power supply voltage, and in the process, the conducting state of the first switch device 102 and the second switch device 104 and the comparison result of the first power supply signal and the preset power supply voltage are related, so that automatic switching of a main power supply (namely the first power supply signal) and a backup power supply (namely the second power supply signal) can be realized, and the power at the position where an output end of the second switch device 104 is connected with the output end of the first switch device 102 can be stably output to meet the actual power supply requirement of a load.
In addition, only one of the first switching device 102 and the second switching device 104 is in a conducting state, so that the first power supply signal and the second power supply signal do not affect each other, and no circulation occurs, that is, the first power supply signal flows back to the second power supply signal, or the second power supply signal flows back to the first power supply signal, and the like, thereby improving the stability of the power switching circuit during operation.
In one embodiment, the first switching device 102 and the second switching device 104 are PhotoMOS, where PhotoMOS refers to a photo coupler that employs an LED in an input element and a MOSFET in an output element.
In the embodiment, the PhotoMOS has good switching characteristic, the PhotoMOS has very low on-resistance with a typical value of 0.11 ohm and very low loss when being conducted, the conduction voltage drop of a common diode is 0.7V, the loss is large when being conducted, and the power consumption of the power supply switching circuit is effectively reduced by applying the PhotoMOS.
In one embodiment, photoMOS can be replaced by the Panasonic brand AQY series, AQZ series, AQV series, AQW series, etc., the Toshiba brand TLP3122, the Alaska ASSR series, etc.
In one embodiment, the first power supply signal has a value ranging from 6V to 36V, such as 9V to 36V or 9.6V to 36V, and the second power supply signal has a value ranging from 9V to 36V, such as 7.2V.
In one embodiment of the present invention, as shown in FIG. 2, the control circuit 106 includes: a first control circuit 1062, the first control circuit 1062 being connected to a control terminal of the first switching device 102, the first control circuit 1062 being configured to control an on/off state of the first switching device 102 according to a comparison result of the first power supply signal and a preset power supply voltage; a second control circuit 1064, the second control circuit 1064 being connected to the first control circuit 1062 and a control end of the second switching device 104, the second control circuit 1064 being configured to control an on-off state of the second switching device 104 according to the comparison result.
In this embodiment, the control circuit 106 includes a first control circuit 1062 and a second control circuit 1064, and since the second control circuit 1064 is connected to the first control circuit 1062, the first control circuit 1062 and the second control circuit 1064 may form an interlock circuit, so as to ensure that only one of the first switching device 102 and the second switching device 104 is in a conducting state at the same time, thereby improving the stability of the power switching circuit during operation.
In any of the above embodiments, based on the first power supply signal being less than the predetermined power supply voltage, the first control circuit controls the first switching device 102 to be in the off state, and the second control circuit controls the second switching device 104 to be in the on state; or based on the first power supply signal being greater than or equal to the predetermined power supply voltage, the first control circuit controls the first switching device 102 to be in the on state, and the second control circuit controls the second switching device 104 to be in the off state.
In this embodiment, when the first power supply signal is smaller than a preset power supply voltage, the first control circuit controls the first switching device 102 to be in an off state, and the second control circuit controls the second switching device 104 to be in an on state, so that when the first power supply signal is insufficient, the second power supply signal is used for supplying power, so that the power switching circuit can stably supply power to the load, and meanwhile, based on the fact that the first power supply signal is greater than or equal to the preset power supply voltage, the first control circuit controls the first switching device 102 to be in the on state, and the second control circuit controls the second switching device 104 to be in the off state, so that the first power supply signal is preferentially used for supplying power.
In any of the above embodiments, as shown in fig. 3, the first control circuit includes: the output end of the third switching device Q1 is grounded; the first switch device 102 comprises a first optical coupler PhotoMOS1, a first input end and a second input end of the first optical coupler PhotoMOS1 receive a first power supply signal, a first output end of the first optical coupler PhotoMOS1 is connected with an input end of a third switch device Q1, and a second output end of the first optical coupler PhotoMOS1 is configured to output the first power supply signal; the second control circuit includes: the output end of the fourth switching device Q2 is grounded; the second switch device 104 comprises a second optical coupler phomos 2, a first input end and a second input end of the second optical coupler phomos 2 receive a second power supply signal, a first output end of the second optical coupler phomos 2 is connected with an input end of the third switch device Q1, and a second output end of the second optical coupler phomos 2 is configured to output the second power supply signal; under the condition that the first input end of the first optical coupler PhotoMOS1 is communicated with the first output end of the first optical coupler PhotoMOS1, the second input end of the first optical coupler PhotoMOS1 is communicated with the second output end of the first optical coupler PhotoMOS1; based on the condition that the first input end of the second optical coupler PhotoMOS2 is communicated with the first output end of the second optical coupler PhotoMOS2, the second input end of the second optical coupler PhotoMOS2 is communicated with the second output end of the second optical coupler PhotoMOS2.
In this embodiment, because the first input end and the second input end of the first opto-coupler photo mos1 included in the first switch device 102 receive the first power supply signal, the first switch signal has an effect of supplying power to the outside through the second input end and the second output end of the first switch device 102, and meanwhile, the first switch signal can also supply power to the first switch device 102 itself, meanwhile, the first output end of the first opto-coupler photo mos1 is connected with the input end of the third switch device Q1, and the output end of the third switch device Q1 is grounded, therefore, the conducting state of the first switch device 102 can be controlled according to the conducting state of the third switch device Q1, and further whether the first power supply signal is output is controlled. In any of the above embodiments, as shown in fig. 3, the first control circuit further includes: the first end of the first resistor R1 receives a first power supply signal; a first end of the second resistor R2 is connected with a second end of the first resistor R1, and a second end of the second resistor R2 is grounded; a first end of the second resistor R2 is connected with a control end of the third switching device Q1; the control end of the third switching device Q1 controls the on-off states of the input end of the third switching device Q1 and the output end of the third switching device Q1 according to the voltage signal of the first end of the second resistor R2.
In this embodiment, the first resistor R1 and the second resistor R2 are connected in series and grounded, and under the action of the first power supply signal, the first resistor R1 and the second resistor R2 perform a voltage division function, which is represented by that a voltage is provided at a position where the first resistor R1 and the second resistor R2 are connected (i.e., at the first end of the second resistor R2), and the voltage corresponds to the first power supply signal, so that the voltage can be used to represent the actual condition of the first power supply signal, and the on-state of the third switching device Q1 can be controlled by comparing the voltage signal with the on-state voltage of the third switching device Q1. In any of the above embodiments, as shown in fig. 3, the method further includes: the cathode of the first diode D1 is connected with the first output end of the first optical coupler PhotoMOS1, and the anode of the first diode D1 is connected with the first input end of the second optical coupler PhotoMOS2; the second control circuit further includes: a first end of the third resistor R3 receives a second power supply signal; a first end of the fourth resistor R4 is connected with a second end of the third resistor R3 and a first input end of the second optocoupler PhotoMOS2, and a second end of the fourth resistor R4 is grounded; the first end of the fourth resistor R4 is connected with the control end of the fourth switching device Q2; the control end of the fourth switching device Q2 controls the on-off states of the input end of the fourth switching device Q2 and the output end of the fourth switching device Q2 according to the voltage signal of the anode of the first diode D1.
In this embodiment, the first diode D1 is used as a clamping diode, and based on the connection relationship with the first opto-coupler phomos 1 and the second opto-coupler phomos 2, the second control circuit may be controlled according to the state of the first control circuit, so as to control the second switching device 104, specifically, when the third switching device Q1 is in a conducting state, the first switching device 102 is conducting, the first power supply signal supplies power, at this time, the cathode of the first diode D1 is clamped to a low level (i.e., position a), the fourth switching device Q2 is in a cut-off state, and at the same time, the second switching device 104 is in a cut-off state, and when the third switching device Q1 is in a cut-off state, the first switching device 102 cuts off, the first power supply signal does not supply power, at this time, the cathode of the first diode D1 is not clamped, the fourth switching device Q2 is in a conducting state, and at the same time, the second switching device 104 is in a conducting state, at this time, the same time, the first switching circuit and the interlocking control circuit is implemented through the first diode D1, and the second switching device 104 is in a stable state, and the stability of the second switching circuit is ensured.
In one embodiment, the third switching device Q1 and the fourth switching device Q2 are transistors. Wherein, the output terminal of the third switching device Q1 is an emitter, the input terminal of the third switching device Q1 is a collector, the control terminal of the third switching device Q1 is a base, the output terminal of the fourth switching device Q2 is an emitter, the input terminal of the fourth switching device Q2 is a collector, and the control terminal of the fourth switching device Q2 is a base, since the first power supply signal is grounded through the first resistor R1 and the second resistor R2, and the control terminal of the third switching device Q1 is connected with the first terminal of the second resistor R2, when the voltage of the first power supply signal changes, the voltage signal input to the control terminal of the third switching device Q1 also changes, when the third switching device Q1 is in a conducting state (i.e., the output end of the third switching device Q1 is communicated with the input end of the third switching device Q1), the first opto-coupler photo mos1 is communicated, at this time, the light emitting device in the first opto-coupler photo mos1 emits light, the corresponding first opto-coupler photo mos1 can output a first power supply signal, and when the first power supply signal is greater than or equal to a preset power supply voltage, because the first diode D1 exists, the cathode of the first diode D1 is clamped to a low level, at this time, the fourth switching device Q2 is in a cut-off state, i.e., the light emitting device in the second opto-coupler photo mos2 does not emit light, and the power supply switching circuit cannot output a second power supply signal; and when the first power supply signal is less than the preset power supply voltage, the third switching device Q1 is in a cut-off state, the corresponding first optical coupler PhotoMOS1 is not communicated, the first diode D1 does not play a role of clamping, at the moment, the fourth switching device Q2 is in a conducting state, namely, the light emitting device in the second optical coupler PhotoMOS2 emits light, and the power supply switching circuit outputs a second power supply signal.
In any of the above embodiments, as shown in fig. 3, the method further includes: and the second diode D2 is connected in series between the first end of the fourth resistor R4 and the control end of the fourth switching device Q2, the anode of the second diode D2 is connected with the first end of the fourth resistor R4, and the cathode of the second diode D2 is connected with the control end of the fourth switching device Q2.
In this embodiment, by setting the second diode D2 and utilizing the characteristic that the diode is turned on and has a conduction voltage drop, the trigger voltage value of the control terminal of the fourth switching device Q2 is increased, the possibility that the fourth switching device Q2 is triggered by mistake is reduced, and the stability of the power switching circuit is further improved.
In any of the above embodiments, as shown in fig. 3, the method further includes: and a first end of the fifth resistor R5 is connected with a first input end of the first optical coupler PhotoMOS1, and a second end of the fifth resistor R5 is configured to receive the first power supply signal.
In this embodiment, the fifth resistor R5, the photodiode in the first opto-coupler PhotoMOS1, and the third switching device Q1 form a series connection, and a preset power supply voltage setting process is realized by controlling the voltage at the cathode position of the diode, so that power supply switching is performed according to actual power supply requirements.
In any of the above embodiments, the fifth resistor R5 is an adjustable resistor.
In the embodiment, the adjustable resistor is convenient to adjust according to the actual requirement of a user, and the power supply switching circuit can adapt to various use environments.
In any of the above embodiments, as shown in fig. 2, the method further includes: and a voltage conversion circuit 108, wherein an input end of the voltage conversion circuit 108 is connected with an output end of the first switching device 102.
In this embodiment, the power switching circuit is connected to the output terminal of the first switching device 102, so as to perform voltage conversion on the received power supply signal and output the power supply signal, so as to meet the power supply requirements of different loads, so that the power switching circuit can adapt to various power requirements.
In one embodiment, the voltage converting circuit 108 (also called a switching power supply module, i.e. DC/DC 1) may be a linear power supply module, where typical switching power supply modules include LM5161, LM2596, etc., and typical linear power supply modules include LM7812, LM2937, etc.
Example two
In one embodiment of the invention, a main power supply (namely a first power supply signal) is connected to a switch power supply module through a first optical coupler PhotoMOS1, a secondary power supply (namely a second power supply signal) is also connected to the switch power supply module through a second optical coupler PhotoMOS2, and the switch power supply module is connected with other circuit loads; the control circuit 1 (namely a first control circuit) controls the on and off of the first optical coupler PhotoMOS1, the control circuit 2 (namely a second control circuit) controls the on and off of the second optical coupler PhotoMOS2, the 2 paths of PhotoMOS form an interlocking circuit, only 1 path of PhotoMOS is switched on at any time, the main power supply and the auxiliary power supply cannot influence each other, and mutual backward flow cannot occur; the main power supply supplies power under normal conditions, the control loop 2 can judge the state of the main power supply through the control loop 1, when the main power supply is powered off, the control loop 1 turns off the first optical coupler PhotoMOS1, the control loop 2 responds quickly, the second optical coupler PhotoMOS2 is switched on, and the circuit is switched to the auxiliary power supply to supply power; similarly, when the main power supply is recovered, the control loop 1 controls the conduction of the first optical coupler PhotoMOS1, the control loop 2 can also respond quickly, the second optical coupler PhotoMOS2 is switched off, and the circuit is switched to the main power supply; the whole process is completely automatic and uninterrupted, so that the automatic uninterrupted switching of the double power supplies is realized.
The following parameters were combined:
PhotoMOS adopts AQY272 of the Song brand, and has an on-resistance of 0.11 ohm.
2.24V is a main power supply, and the voltage range is 9V-36V; vbat is an auxiliary power supply and is connected with a 7.2V battery; VIN is connected to the following power module.
V24A is connected to VIN through a (first optical coupler PhotoMOS 1); vbat is connected to VIN through a second opto-coupler PhotoMOS2, and VIN is connected with the switch power supply module.
The specific contents of the embodiment are as follows: the first resistor R1, the second resistor R2, the fifth resistor R5 and the third switching device Q1 form a control loop 1 to control the first optocoupler PhotoMOS1; a control loop 2 consisting of a third resistor R3, a fourth resistor R4, a second diode D2 and a fourth switching device Q2 controls a second optocoupler PhotoMOS2; the first diode D1 is used as a clamping diode, and the control loop 2 can respond in real time according to the state of the control loop 1 to judge whether to turn off or turn on the second optocoupler PhotoMOS2. When the main power supply is 9.6V-36V, the third switching device Q1 is turned on, so that the first opto-coupler PhotoMOS1 is turned on, and the system is powered by the main power supply; at the moment, the first diode D1 is clamped to the ground level, the fourth switching device Q2 is closed, and the second opto-coupler PhotoMOS2 is controlled to be closed; when the main power supply is lower than 9.6V, the third switching device Q1 is closed, so that the first optocoupler PhotoMOS1 is closed, the first diode D1 is not clamped to the ground level at the moment, the fourth switching device Q2 is opened, the second optocoupler PhotoMOS2 is controlled to be opened, and the system is automatically switched to the auxiliary power supply for supplying power.
The lowest voltage of the main power supply can be adjusted by adjusting the resistance value of the fifth resistor R5; the typical voltage drop of the LED of the first optical coupler PhotoMOS1 is 1.2V, the conducting voltage drop of the third switching device Q1 is 0.3V, the typical starting current of the first optical coupler PhotoMOS1 is 1mA, the fifth resistor R5 is a current-limiting resistor, and when the resistance value of the fifth resistor R5 is 8K, the lowest voltage of the main power supply is about 9.5V. If the resistance value of the fifth resistor R5 is reduced, the lowest voltage of the main power supply is correspondingly reduced; and if the resistance value of the fifth resistor R5 is increased, the lowest voltage of the main power supply is correspondingly increased.
As shown in fig. 4, a circuit configuration of a voltage conversion circuit is given in which WIN in the voltage conversion circuit is connected to WIN in the power supply switching circuit.
In the embodiment, a main power supply is supplied with 9.6-36V, a standby battery is supplied with 7.2V, and double power supplies are supplied with power; the automatic uninterrupted switching is realized by completely adopting the construction of discrete devices without additional chip control; no circulation current exists, and the current cannot flow to the other power supply; the loss of the primary and secondary power supply loops is very low, particularly, a special power supply chip is not needed to participate in monitoring of a main power supply, uninterrupted automatic switching of the primary and secondary power supplies is completely realized by discrete devices, flexibility is improved, popularization is facilitated, and meanwhile, the loss of the primary and secondary power supply loops is reduced.
In the description of the present invention, the terms "plurality" or "a plurality" refer to two or more, and unless otherwise specifically limited, the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are merely for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention; the terms "connected," "mounted," "secured," and the like are to be construed broadly and include, for example, fixed connections, removable connections, or integral connections; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the description of the present invention, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In the present invention, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A power switching circuit, comprising:
a first switching device configured to receive a first supply signal and output;
a second switching device, an output terminal of the second switching device being connected to an output terminal of the first switching device, the second switching device being configured to receive a second supply signal and output the second supply signal;
the control circuit is connected with the control end of the first switching device and the control end of the second switching device, and is configured to selectively control any one of the first switching device and the second switching device to be in a conducting state and the other switching device to be in a stopping state according to a comparison result of the first power supply signal and a preset power supply voltage;
the control circuit includes:
a first control circuit connected to a control terminal of the first switching device, the first control circuit being configured to control an on-off state of the first switching device according to a comparison result of the first power supply signal and a preset power supply voltage;
the first control circuit includes: a third switching device, an output terminal of the third switching device being grounded;
the first switch device comprises a first optical coupler, a first input end and a second input end of the first optical coupler receive the first power supply signal, a first output end of the first optical coupler is connected with an input end of the third switch device, and a second output end of the first optical coupler is configured to output the first power supply signal;
based on under the condition that the first input end of first opto-coupler with the first output end of first opto-coupler intercommunication, the second input end of first opto-coupler with the second output end of first opto-coupler intercommunication.
2. The power switching circuit of claim 1, wherein the control circuit comprises:
a second control circuit connected to the first control circuit and a control end of the second switching device, the second control circuit configured to control an on-off state of the second switching device according to the comparison result.
3. The power switching circuit of claim 2,
based on the fact that the first power supply signal is smaller than a preset power supply voltage, the first control circuit controls the first switching device to be in an off state, and the second control circuit controls the second switching device to be in an on state; or
Based on the first power supply signal being greater than or equal to a preset power supply voltage, the first control circuit controls the first switching device to be in a conducting state, and the second control circuit controls the second switching device to be in a disconnecting state.
4. The power switching circuit of claim 2,
the second control circuit includes: a fourth switching device, an output terminal of the fourth switching device being grounded;
the second switching device comprises a second optical coupler, a first input end and a second input end of the second optical coupler receive the second power supply signal, a first output end of the second optical coupler is connected with an input end of the third switching device, and a second output end of the second optical coupler is configured to output the second power supply signal;
and on the basis of the condition that the first input end of the second optical coupler is communicated with the first output end of the second optical coupler, the second input end of the second optical coupler is communicated with the second output end of the second optical coupler.
5. The power switching circuit of claim 4, wherein the first control circuit further comprises:
a first resistor, a first end of which receives a first power supply signal;
a first end of the second resistor is connected with a second end of the first resistor, and a second end of the second resistor is grounded;
the first end of the second resistor is connected with the control end of the third switching device;
the control end of the third switching device controls the on-off states of the input end of the third switching device and the output end of the third switching device according to the voltage signal of the first end of the second resistor.
6. The power switching circuit of claim 5, further comprising:
the negative electrode of the first diode is connected with the first output end of the first optocoupler, and the positive electrode of the first diode is connected with the first input end of the second optocoupler;
the second control circuit further comprises:
a third resistor, a first end of the third resistor receiving a second power supply signal;
a first end of the fourth resistor is connected with a second end of the third resistor and a first input end of the second optocoupler, and a second end of the fourth resistor is grounded;
a first end of the fourth resistor is connected with a control end of the fourth switching device;
the control end of the fourth switching device controls the on-off state of the input end of the fourth switching device and the output end of the fourth switching device according to the voltage signal of the anode of the first diode.
7. The power switching circuit of claim 6, further comprising:
the second diode is connected between the first end of the fourth resistor and the control end of the fourth switching device in series, the anode of the second diode is connected with the first end of the fourth resistor, and the cathode of the second diode is connected with the control end of the fourth switching device.
8. The power switching circuit according to any one of claims 4 to 7, further comprising:
a fifth resistor, a first end of the fifth resistor being connected with a first input end of the first optocoupler, a second end of the fifth resistor being configured to receive the first supply signal.
9. The power switching circuit of claim 8,
the fifth resistor is an adjustable resistor.
10. The power switching circuit according to any one of claims 1 to 7, further comprising:
and the input end of the voltage conversion circuit is connected with the output end of the first switching device.
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| CN114665584A (en) * | 2019-12-19 | 2022-06-24 | 华为数字能源技术有限公司 | Power supply device and power supply system |
| CN112615419B (en) * | 2020-12-18 | 2024-02-27 | 上海微阱电子科技有限公司 | Dual-power automatic switching circuit |
| CN113572256A (en) * | 2021-07-30 | 2021-10-29 | 杭州海兴电力科技股份有限公司 | Low-voltage drop dual-power supply circuit |
| CN113467335A (en) * | 2021-07-30 | 2021-10-01 | 苏州浪潮智能科技有限公司 | Power supply control circuit, power supply control device and server |
| CN117578387B (en) * | 2023-10-27 | 2024-08-09 | 深圳市安保医疗科技股份有限公司 | Control circuit of multiple input power supply and switching power supply equipment |
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| DE102014107019A1 (en) * | 2014-05-19 | 2015-11-19 | Fujitsu Technology Solutions Intellectual Property Gmbh | Power supply arrangement for an electronic device |
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