CN207625292U - Power supply switching circuit and television power supply system - Google Patents
Power supply switching circuit and television power supply system Download PDFInfo
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- CN207625292U CN207625292U CN201721286753.9U CN201721286753U CN207625292U CN 207625292 U CN207625292 U CN 207625292U CN 201721286753 U CN201721286753 U CN 201721286753U CN 207625292 U CN207625292 U CN 207625292U
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Abstract
The utility model discloses a power supply switching circuit, which comprises a control module and a power supply switching module; the control module is provided with an AC voltage detection end, a DC voltage detection end and a switching control end; the power supply switching module is provided with an AC power supply input end, a DC power supply input end, a switching controlled end and a power supply output end; a television power supply system comprising: the television comprises a DC power supply module, an AC-DC conversion circuit, a power supply switching circuit and a television working module. The television power supply system is provided with the DC power supply module, the AC-DC conversion circuit and the power supply switching circuit, so that the television power supply system can be compatible with two power supply modes of AC power supply and DC power supply.
Description
Technical field
The utility model belongs to power supply system for electrical domain, and in particular to a kind of power supply switch circuit and TV power supply system
System.
Background technology
To the demand of uninterruptible power supply and power supply diversity, more stringent requirements are proposed at this stage, and traditional TV power supply
System can only be powered by AC, can not compatible battery or adapter power supply, TV is stopped at once when causing to power off suddenly；
Also it cannot achieve when AC and DC while while powering power to AC preferred, great inconvenience caused to user.
Utility model content
The purpose of this utility model is to provide a kind of power supply switch circuit and TV power supply system, realize when AC power supplies and
It is preferentially powered using AC power supplies by internal power supply switch circuit when DC power supply is simultaneously powered TV so that TV supplies
Both power supply modes that the compatible AC power supplies of electric system is powered and DC power supply is powered.
In order to solve the above technical problems, the utility model embodiment provides a kind of power supply switch circuit, including control module
With power supply handover module；Wherein, the control module has AC voltage detectings end, D/C voltage test side and switching control end；Institute
Power supply handover module is stated with AC power input, DC power supply input terminal, switching controlled end and power output end；
The AC voltage detectings end of the control module is connect with the AC power input of the power supply handover module, the control
The D/C voltage test side of molding block is connect with the DC power supply input terminal of the power supply handover module, the switching control of the control module
End processed is connect with the switching controlled end of the power supply handover module；The AC power input of the power supply handover module and the electricity
The power output end of source handover module connects.
Further, the control module includes：First resistor, second resistance, 3rd resistor, the 4th resistance, first open
Close pipe and second switch pipe；
The first end of the first resistor is connect with the AC voltage detectings end of the control module, and the of the first resistor
Two ends are connect with the first end of the second resistance；The first end of the second resistance and the control terminal of the first switch pipe connect
It connects, the second end ground connection of the second resistance；The output end of the first switch pipe is grounded；The first of the third current-limiting resistance
End is connect with the D/C voltage test side of the control module, the control of the second end of the 3rd resistor and the second switch pipe
End connection, the second end of the 3rd resistor are also connect with the input terminal of the first switch pipe；The first of 4th resistance
End is connect with the second end of the 3rd resistor, the second end ground connection of the 4th resistance；The input terminal of the second switch pipe
It is connect with the switching control end of the control module, the D/C voltage of the input terminal of the second switch pipe also with the control module
Test side connects, the output end ground connection of the second switch pipe.
Preferably, the control module further includes：First capacitance, the 5th resistance, the 6th resistance, the 7th resistance and the 8th electricity
Resistance；
5th resistance is connected between the second end of the first resistor and the control terminal of the first switch pipe；Institute
The 6th resistance is stated to be connected between the second end of the 3rd resistor and the control terminal of the second switch pipe；7th resistance
It is connected between the input terminal of the second switch pipe and the switching control end of the control module；8th resistance is connected to
Between the input terminal of the second switch pipe and the D/C voltage test side of the control module；The first end of first capacitance with
The first end of the second resistance connects, and the second end of first capacitance is connect with the second end of the second resistance.
Further, the power supply handover module includes：Switching switch and the first diode；
The control terminal of the switching switch is connect with the switching controlled end of the power supply handover module, the switching switch
Input terminal is connect with the DC power supply input terminal of the power supply handover module, and the output end of the switching switch switches with the power supply
The power output end of module connects；First diode be connected to the AC power input of the power supply handover module with it is described
Between the power output end of power supply handover module；Wherein, the AC of the anode and the power supply handover module of first diode
Power input connects, and the cathode of first diode is connect with the power output end of the power supply handover module.
Preferably, the power supply handover module further includes the second diode, the second capacitance and power supply ground capacity；
The power supply that second diode is connected to the output end and the power supply handover module of the switching switch exports
Between end；Wherein, the anode of second diode is connect with the output end of the switching switch, and second diode is born
Pole is connect with the power output end of the power supply handover module；The first end of second capacitance and the power supply handover module
Power output end connects, the second end ground connection of second capacitance；The first end of the power supply ground capacity and second electricity
The first end of appearance connects, the second end ground connection of the power supply ground capacity.
Preferably, the switching switch is P-channel metal-oxide-semiconductor；
The control terminal of the switching switch corresponds to the grid of the P-channel metal-oxide-semiconductor, the input terminal pair of the switching switch
The source electrode of the P-channel metal-oxide-semiconductor is should be, the output end of the switching switch corresponds to the drain electrode of the P-channel metal-oxide-semiconductor.
The utility model embodiment also provides a kind of TV power supply system, including：DC power module, AC-DC transformation electricity
Road, power supply switch circuit and television operations module；
The DC power module has DC power supply output end；The AD-DC translation circuits have DC power supply output end and use
In the AC power input of input AC alternating current；The television operations module has power input；
The DC power supply output end of the DC power module is connect with the DC power supply input terminal of the power supply switch circuit；It is described
The DC power supply output end of AC-DC translation circuits is connect with the AC power input of the power supply switch circuit；The power supply switching
The power output end of circuit is connect with the power input of the television operations module.
Further, the TV power supply system, further include be connected to the DC power supply output end of the DC power module with
Under-voltage overvoltage crowbar between the DC power supply input terminal of the power supply switch circuit；Wherein, the under-voltage overvoltage protection electricity
Road includes：Under-voltage detection unit, over-pressed detection unit and cut-off switch；
The cut-off switch has power input, switch control terminal and power output end；The overvoltage detection unit tool
There are over-pressed test side and over-pressed control terminal；The under-voltage detection unit has under-voltage test side and under-voltage control terminal；
The power input of the cut-off switch is connect with the DC power supply output end of the DC power module, and the power-off is opened
The power output end of pass is connect with the DC power supply input terminal of the power supply switch circuit；
The under-voltage test side of the under-voltage detection unit is connect with the power input of the cut-off switch, the under-voltage inspection
The under-voltage control terminal for surveying unit is connect with the switch control terminal of the cut-off switch；The over-pressed test side of the overvoltage detection unit
It is connect with the power input of the cut-off switch, the overvoltage over-pressed control terminal of detection unit and opening for the cut-off switch
Close control terminal connection.
Further, the under-voltage detection unit includes the first divider resistance, the second divider resistance and third switching tube；
The first end of first divider resistance is connect with the under-voltage test side of the under-voltage detection unit, described first point
The second end of piezoresistance is connect with the first end of second divider resistance；The first end of second divider resistance and described the
The control terminal of three switching tubes connects, the second end ground connection of second divider resistance；The input terminal of the third switching tube and institute
The under-voltage control terminal connection of under-voltage detection unit is stated, the input terminal of the third switching tube is also deficient with the under-voltage detection unit
Press test side connection, the output end ground connection of the third switching tube.
Further, the over-pressed detection unit includes：4th switching tube, third divider resistance and the 4th divider resistance；
The first end of the third divider resistance is connect with the over-pressed test side of the over-pressed detection unit, the third point
The second end of piezoresistance is connect with the control terminal of the 4th switching tube；The input terminal of 4th switching tube is examined with the overvoltage
The over-pressed test side connection of unit is surveyed, the output end of the 4th switching tube and the over-pressed control terminal of the over-pressed detection unit connect
It connects；The first end of 4th divider resistance is connect with the second end of the third divider resistance, the 4th divider resistance
Second end is grounded.
Compared with the prior art, a kind of power supply switch circuit of the utility model and the advantageous effect of TV power supply system exist
In：The power supply handover module in power supply switch circuit is controlled by the control module in power supply switch circuit, AC power supplies is worked as in realization
When being powered simultaneously to rear end with DC power supply, power supply handover module blocks the preferential selection AC power supplies of DC power supply power supply to supply rear end
Electricity meets and preferentially uses AC electricity by internal power supply switch circuit when AC power supplies and DC power supply are simultaneously powered TV
Source powers, and TV power supply system has DC power module, AC-DC translation circuits and power supply switch circuit so that TV power supply system
Both power supply modes that compatible AC power supplies of uniting is powered and DC power supply is powered.
Description of the drawings
Fig. 1 is the structural schematic diagram of one embodiment of power supply switch circuit provided by the utility model；
Fig. 2 is the circuit diagram of another embodiment of power supply switch circuit provided by the utility model；
Fig. 3 is the structural schematic diagram of TV power supply system provided by the utility model；
Fig. 4 is the electricity of one embodiment of the under-voltage overvoltage crowbar in TV power supply system provided by the utility model
Road schematic diagram.
Specific implementation mode
The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model
Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole
Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without creative efforts
The every other embodiment obtained, shall fall within the protection scope of the present invention.
It is the structural schematic diagram of one embodiment of power supply switch circuit provided by the utility model, the power supply referring to Fig. 1
Switching circuit includes：Control module 10 and power supply handover module 20；Wherein, the control module 10 have AC voltage detectings end,
D/C voltage test side and switching control end；The power supply handover module 20 has AC power input, DC power supply input terminal, switching
Controlled end and power output end；
The AC voltage detectings end of the control module 10 is connect with the AC power input of the power supply handover module 20, institute
The D/C voltage test side for stating control module 10 is connect with the DC power supply input terminal of the power supply handover module 20, the control module
10 switching control end is connect with the switching controlled end of the power supply handover module 20；The AC power supplies of the power supply handover module 20
Input terminal is connect with the power output end of the power supply handover module 20.
It should be noted that a kind of power supply switch circuit provided by the utility model, passes through the control in power supply switch circuit
Molding block controls the power supply handover module in power supply switch circuit, realizes when AC power supplies and DC power supply are simultaneously powered rear end
When, power supply handover module blocks the preferential selection AC power supplies of DC power supply power supply to power rear end, meets when AC power supplies and DC power supply are same
When preferentially powered using AC power supplies by internal power supply switch circuit when being powered to TV.
As shown in Fig. 2, being the circuit diagram of another embodiment of power supply switch circuit provided by the utility model.
Power supply switch circuit provided in this embodiment on the basis of the above embodiments, has advanced optimized partial function electricity
The structure on road, it is specific as follows：
The control module 10 includes：First resistor R1, second resistance R2,3rd resistor R3, the 4th resistance R4, first open
Close pipe Q1 and second switch pipe Q2；
The first end of the first resistor R1 is connect with the AC voltage detectings end of the control module 10, the first resistor
The second end of R1 is connect with the first end of the second resistance R2；The first end of the second resistance R2 and the first switch pipe
The control terminal of Q1 connects, the second end ground connection of the second resistance R2；The output end of the first switch pipe Q1 is grounded；Described
The first end of three current-limiting resistance R3 is connect with the D/C voltage test side of the control module 10, the second end of the 3rd resistor R3
It is connect with the control terminal of the second switch pipe Q2, the second end of the 3rd resistor R3 is also defeated with the first switch pipe Q1
Enter end connection；The first end of the 4th resistance R4 is connect with the second end of the 3rd resistor R3, the 4th resistance R4's
Second end is grounded；The input terminal of the second switch pipe Q2 is connect with the switching control end of the control module 10, and described second
The input terminal of switching tube Q2 is also connect with the D/C voltage test side of the control module 10, the output end of the second switch pipe Q2
Ground connection.
Preferably, the first resistor R1 and the second resistance R2 form bleeder circuit in the control module 10,
It act as adjusting the threshold value that the voltage of the AC voltage detectings end input of the control module 10 makes the first switch pipe Q1 be connected
Voltage, threshold voltage=0.6 × (R1+R2)/R2, i.e., when TV is inserted into AC power supplies, the AC voltage detectings of the control module 10
The voltage of end input is begun to ramp up by 0V, and when voltage rises to threshold voltage, the voltage at the both ends the second resistance R2 is at this time
0.6V is just connected the first switch pipe Q1.Similarly, the 3rd resistor R3 and the 4th resistance R4 are also in the control
Form bleeder circuit in molding block 10, act as adjusting the D/C voltage test side input of the control module 10 voltage make it is described
The threshold voltage of second switch pipe Q2 conductings.
Preferably, the control module 10 further includes：First capacitance C1, the 5th resistance R5, the 6th resistance R6, the 7th resistance
R7 and the 8th resistance R8；
The 5th resistance R5 is connected to the control terminal of the second end and the first switch pipe Q1 of the first resistor R1
Between；The 6th resistance R6 be connected to the second end of the 3rd resistor R3 and the second switch pipe Q2 control terminal it
Between；The 7th resistance R7 be connected to the input terminal of the second switch pipe Q2 and the control module 10 switching control end it
Between；The 8th resistance R8 is connected to the D/C voltage test side of the input terminal and the control module 10 of the second switch pipe Q2
Between；The first end of the first capacitance C1 is connect with the first end of the second resistance R2, and the second of the first capacitance C1
End is connect with the second end of the second resistance R2.
Further, the power supply handover module 20 includes：Switch switch QM1 and the first diode D1；
The control terminal of the switching switch QM1 is connect with the switching controlled end of the power supply handover module 20, the switching
The input terminal of switch QM1 is connect with the DC power supply input terminal of the power supply handover module 20, the output end of the switching switch QM1
It is connect with the power output end of the power supply handover module 20；The first diode D1 is connected to the power supply handover module 20
AC power input and the power output end of the power supply handover module 20 between；Wherein, the first diode D1 is being just
Pole is connect with the AC power input of the power supply handover module 20, and cathode and the power supply of the first diode D1 switch
The power output end of module 20 connects.
Preferably, the switching switch QM1 is P-channel metal-oxide-semiconductor；
The control terminal of the switching switch QM1 corresponds to the grid of the P-channel metal-oxide-semiconductor, and the switching switch QM1's is defeated
Enter the source electrode that end corresponds to the P-channel metal-oxide-semiconductor, the output end of the switching switch QM1 corresponds to the P-channel metal-oxide-semiconductor
Drain electrode.
When the DC power supply input terminal of the power supply handover module 20 accesses the AC electricity of power supply and the power supply handover module 20
When source input terminal is without access power supply, the controlled system conductings of the switching switch QM1 are made described due to the presence of the first diode D1
The electric current of the DC power supply input terminal access of power supply handover module 20 is output to the power output end of the power supply handover module 20
Load, and can not reverse irrigated current to the power supply handover module 20 AC power input.
When the AC power input of the power supply handover module 20 accesses power supply, the switching switch QM1 is cut by control
Only, since the switching switch QM1 is P-channel metal-oxide-semiconductor, cut-off state can form body diode between hourglass source electrode, wherein
Drain electrode is the cathode of body diode, then the AC power input of the power supply handover module 20 will not pour in down a chimney electricity by body diode
The DC power supply input terminal of the power supply handover module 20 is flowed to, and is switching to the mains-supplied of AC power input access
Moment, due to its brownout, DC power supply input terminal can still supply electricity to the load of power output end by body diode.
Preferably, the power supply handover module 20 further includes the second diode D2, the second capacitance C2 and power supply ground capacity
E1；It is described that the second diode D2 can prevent from having when the power output end external load of power supply handover module electric current to pour in down a chimney back
Power supply handover module 20.
The second diode D2 is connected to the electricity of the output end and the power supply handover module 20 of the switching switch QM1
Between source output terminal；Wherein, the anode of the second diode D2 is connect with the output end for switching switch QM1, and described the
The cathode of two diode D2 is connect with the power output end of the power supply handover module 20；The first end of the second capacitance C2 with
The power output end of the power supply handover module 20 connects, the second end ground connection of the second capacitance C2；It is described electric for electrical ground
The first end for holding E1 is connect with the first end of the second capacitance C2, the second end ground connection of the power supply ground capacity E1.
Below using the external load of the power output end of power supply handover module as TV, using " power supply as AC power supplies, example
Such as alternating current；For DC power supply, such as battery ", the operation principle of the present embodiment is described：
When TV is powered using DC power supply powers without connecing AC power supplies, the AC voltage detectings end of the control module 10
No-voltage signal inputs, since the second end ground connection of second resistance R2 is supplied to the control terminal low level of the first switch pipe Q1
Signal, then the first switch pipe Q1 cut-offs；The D/C voltage test side of the control module 10 detects voltage signal input simultaneously
Give one high level signal of control terminal of the second switch pipe Q2 so that the second switch pipe Q2 conductings, described second
The input terminal of switching tube Q2 is connect with the D/C voltage test side of the control module 10, due to the output of the second switch pipe Q2
End ground connection makes the input terminal high level of second switch pipe Q2 be pulled low, and the switching control end of the control module 10 is caused to export
Low level；The switching controlled end of the power supply handover module 20 receives low level signal so that the switching switch QM1 is led
Logical, the DC power supply input terminal of the power supply handover module 20 is connected with power output end, and DC power supply is powered rear end.
When TV has DC power supply power supply to be inserted into AC power supplies again, the AC voltage detectings end of the control module 10 detects electricity
Pressure signal inputs and gives one high level signal of control terminal of the first switch pipe Q1 so that the first switch pipe Q1 is led
It is logical, the level for the control terminal for inputting the second switch pipe Q2 is dragged down since the output end of the first switch pipe Q1 is grounded,
So that the second switch pipe Q2 cut-offs, due to the D/C voltage of the input terminal and the control module 10 of the second switch pipe Q2
Test side connects so that the switching control end of the control module 10 exports high level signal to the power supply handover module 20
Switch controlled end, the switching switch QM1 is caused to end, DC power supply input terminal and the power supply of the power supply handover module 20 export
End is not turned on, and DC power supply is not powered rear end；AC power input due to the power supply handover module 20 and the electricity
The power output end of source handover module 20 connects, then AC power supplies is powered rear end by the first diode D1, i.e., when AC electricity
When source and DC power supply are simultaneously powered rear end, control module 10 controls power supply handover module 20 and blocks DC power supply power supply preferential
AC power supplies is selected to power rear end.
As shown in figure 3, the utility model embodiment also provides a kind of TV power supply system, including：DC power module 301,
AC-DC translation circuits 302, power supply switch circuit 303 and television operations module 304；
The DC power module 301 has DC power supply output end；The AD-DC translation circuits 302 are exported with DC power supply
End and for input AC alternating current AC power input；The television operations module 304 has power input；
The DC power supply output end of the DC power module 301 connects with the DC power supply input terminal of the power supply switch circuit 303
It connects；The DC power supply output end of the AC-DC translation circuits 302 connects with the AC power input of the power supply switch circuit 303
It connects；The power output end of the power supply switch circuit 303 is connect with the power input of the television operations module 304.
Preferably, the television operations module 304 includes：The constant-current circuit of backlight, that is, inside television lamp bar power supply, with
TV master chips are audio and video processing circuit and the port of core and its periphery；The AD-DC translation circuits 302 are by electric main
AC power supplies be converted into the 12V power supplys exported from DC power supply output end.
Further, the TV power supply system further includes the DC power supply output end for being connected to the DC power module 301
Under-voltage overvoltage crowbar 305 between the DC power supply input terminal of the power supply switch circuit 303；
As shown in figure 4, being one of the under-voltage overvoltage crowbar 305 in TV power supply system provided by the utility model
The circuit diagram of embodiment；Wherein, the under-voltage overvoltage crowbar 305 includes：Under-voltage detection unit 30, overvoltage detection are single
40 and cut-off switch Q5 of member；
The cut-off switch Q5 has power input, switch control terminal and power output end；The overvoltage detection unit
40 have over-pressed test side and over-pressed control terminal；The under-voltage detection unit 30 has under-voltage test side and under-voltage control terminal；
The power input of the cut-off switch Q5 is connect with the DC power supply output end of the DC power module 301, described
The power output end of cut-off switch Q5 is connect with the DC power supply input terminal of the power supply switch circuit 303；
The under-voltage test side of the under-voltage detection unit 30 is connect with the power input of the cut-off switch Q5, described to owe
The under-voltage control terminal of pressure detection unit 30 is connect with the switch control terminal of the cut-off switch Q5；The overvoltage detection unit 40
Over-pressed test side is connect with the power input of the cut-off switch Q5, the over-pressed control terminal of the overvoltage detection unit 40 and institute
State the switch control terminal connection of cut-off switch Q5.
Further, the under-voltage detection unit 30 includes the first divider resistance RD1, the second divider resistance RD2 and third
Switching tube Q3, zener diode D3, resistance R9 and resistance R10；
The first end of the first divider resistance RD1 is connect with the under-voltage test side of the under-voltage detection unit 30, described
The second end of first divider resistance RD1 is connect with the cathode of the zener diode D3；The zener diode D3 anode with
The first end of the second divider resistance RD2 connects；The first end of the second divider resistance RD2 and the third switching tube Q3
Control terminal connection, the second divider resistance RD2 second end ground connection；The input terminal of the third switching tube Q3 passes through resistance
R10 is connect with the under-voltage control terminal of the under-voltage detection unit 30, the input terminal of the third switching tube Q3 by resistance R9 also
It is connect with the under-voltage test side of the under-voltage detection unit 30, the output end ground connection of the third switching tube Q3.
Further, the over-pressed detection unit 40 includes：4th switching tube Q4, third divider resistance RD3 and the 4th point
Piezoresistance RD4；
The first end of the third divider resistance RD3 is connect with the over-pressed test side of the over-pressed detection unit 40, described
The second end of third divider resistance RD3 is connect with the control terminal of the 4th switching tube Q4；The input of the 4th switching tube Q4
The over-pressed test side with the over-pressed detection unit 40 is held to connect, the output end of the 4th switching tube Q4 is detected with the overvoltage
The over-pressed control terminal of unit 40 connects；The first end of the 4th divider resistance RD4 and the second of the third divider resistance RD3
End connection, the second end ground connection of the 4th divider resistance.
When the under-voltage overvoltage crowbar 305 works, when the voltage of the power input of the cut-off switch Q5 reduces,
Voltage detected by the under-voltage test side of the under-voltage detection module 30 becomes smaller, then flows through in the under-voltage detection unit 30
The electric current of second divider resistance RD2 reduces, the voltage U at the both ends the second divider resistance RD2RD2Also can reduce therewith；Due to mistake
Piezoelectricity pressure point be more than brownout voltage point, it is described overvoltage detection unit 40 when cut-off switch Q5 power input voltage drop down to
When below brownout voltage point, the voltage U at the both ends third divider resistance RD3 of the overvoltage detection unit 40RD3Less than the described 4th
The conduction threshold of switching tube Q4, the 4th switching tube Q4 cut-offs, therefore the over-pressed detection unit 40 is not involved in described in control
Cut-off switch Q5；
When the voltage drop of the power input of the cut-off switch Q5 is down to below brownout voltage point, the under-voltage detection
The voltage U at the second both ends divider resistance RD2 of unit 30RD2Less than the conduction threshold of the third switching tube Q3, the third is opened
Pipe Q3 cut-off is closed, the under-voltage detection unit is drawn high by resistance R10 in the under-voltage detection unit 30 and resistance R9 at this time
The level of 30 under-voltage control terminal so that the input terminal of the third switching tube Q3 gives the under-voltage of the under-voltage detection unit 40
Control terminal high level signal；After the switch control terminal of the cut-off switch Q5 receives high level signal, the cut-off switch Q5
Become ending from conducting so that the power output end of cut-off switch Q5 is not powered rear end, by under-voltage detection unit 30,
Mutual cooperation between over-pressed detection unit 40 and cut-off switch Q5, to realize the under-voltage protection function of power circuit.
When the under-voltage overvoltage crowbar 305 works normally, i.e., when the voltage of the power input of cut-off switch Q5 is big
In brownout voltage point and when less than over-pressed electrical voltage point, the voltage at the both ends third divider resistance RD3 of the overvoltage detection unit 40
URD3Less than the conduction threshold of the 4th switching tube Q4, the 4th switching tube Q4 cut-offs, the overvoltage detection unit 40 is not joined
With control the cut-off switch Q5, the voltage U at the second both ends divider resistance RD2 of the under-voltage detection unit 30RD2More than described
The conduction threshold of third switching tube Q3, the third switching tube Q3 conductings, since the output end of the third switching tube Q3 is grounded
So that the input terminal high level of the third switching tube Q3 is pulled low, cause the under-voltage control terminal of the under-voltage detection unit 30 defeated
Go out low level, so that the cut-off switch Q5 is connected, the power output end of the cut-off switch Q5 is to rear end normal power supply.
When the under-voltage overvoltage crowbar 305 works, when the voltage of the power input of the cut-off switch Q5 increases,
Voltage detected by the over-pressed test side of the overvoltage detection module 40 becomes larger, then flows through in the over-pressed detection module 40
The electric current of third divider resistance RD3 increases；When the voltage of the power input of the cut-off switch Q5 is increased to over-pressed electrical voltage point
When above, the voltage U at the both ends third divider resistance RD3 of the overvoltage detection unit 40RD3More than the 4th switching tube Q4's
It is single to give the overvoltage detection by the input terminal of the 4th switching tube Q4 for conduction threshold, the 4th switching tube Q4 conductings
The over-pressed control terminal high level signal of member 40；Since over-pressed electrical voltage point is more than brownout voltage point, the under-voltage detection unit 30 is worked as
When the voltage of the power input of cut-off switch Q5 is increased to over-pressed electrical voltage point or more, second point of the under-voltage detection unit 30
The voltage U at the both ends piezoresistance RD2RD2More than the conduction threshold of the third switching tube Q3, the third switching tube Q3 conductings, institute
It is all pull-up resistor to state resistance R10 and resistance R9 in under-voltage detection unit 30 so that the switch control of final cut-off switch Q5
Termination receives high level signal, and the cut-off switch Q5 becomes ending from being connected so that the power output end of cut-off switch Q5 is not
Rear end is powered, by the mutual cooperation between under-voltage detection unit 30, over-pressed detection unit 40 and cut-off switch Q5 from
And realize the over-voltage protecting function of power circuit.
In conclusion a kind of power supply switch circuit of the utility model and the advantageous effect of TV power supply system are：It is logical
The power supply handover module in the control module control power supply switch circuit in power supply switch circuit is crossed, is realized when AC power supplies and DC electricity
When source is simultaneously powered rear end, power supply handover module blocks the preferential selection AC power supplies of DC power supply power supply to power rear end, full
It is preferentially supplied enough using AC power supplies by internal power supply switch circuit when AC power supplies and DC power supply are simultaneously powered TV
Electricity, TV power supply system have DC power module, AC-DC translation circuits and power supply switch circuit so that TV power supply system can
Compatible AC-3 power supply power supply and DC power supply are powered both power supply modes.
The above is preferred embodiments of the present invention, it is noted that for the ordinary skill of the art
For personnel, without departing from the principle of this utility model, several improvements and modifications can also be made, these are improved and profit
Decorations are also considered as the scope of protection of the utility model.
Claims (10)
1. a kind of power supply switch circuit, which is characterized in that including control module and power supply handover module；Wherein, the control mould
Block has AC voltage detectings end, D/C voltage test side and switching control end；The power supply handover module have AC power input,
DC power supply input terminal, switching controlled end and power output end；
The AC voltage detectings end of the control module is connect with the AC power input of the power supply handover module, the control mould
The D/C voltage test side of block is connect with the DC power supply input terminal of the power supply handover module, the switching control end of the control module
It is connect with the switching controlled end of the power supply handover module；The AC power input of the power supply handover module is cut with the power supply
Change the mold the power output end connection of block.
2. power supply switch circuit as described in claim 1, which is characterized in that the control module includes：First resistor, second
Resistance, 3rd resistor, the 4th resistance, first switch pipe and second switch pipe；
The first end of the first resistor is connect with the AC voltage detectings end of the control module, the second end of the first resistor
It is connect with the first end of the second resistance；The first end of the second resistance is connect with the control terminal of the first switch pipe,
The second end of the second resistance is grounded；The output end of the first switch pipe is grounded；The first end of the 3rd resistor and institute
The D/C voltage test side connection of control module is stated, the second end of the 3rd resistor and the control terminal of the second switch pipe connect
It connects, the second end of the 3rd resistor is also connect with the input terminal of the first switch pipe；The first end of 4th resistance with
The second end of the 3rd resistor connects, the second end ground connection of the 4th resistance；The input terminal of the second switch pipe and institute
The switching control end connection of control module is stated, the input terminal of the second switch pipe is also detected with the D/C voltage of the control module
End connection, the output end ground connection of the second switch pipe.
3. power supply switch circuit as claimed in claim 2, which is characterized in that the control module further includes：First capacitance,
Five resistance, the 6th resistance, the 7th resistance and the 8th resistance；
5th resistance is connected between the second end of the first resistor and the control terminal of the first switch pipe；Described
Six resistance are connected between the second end of the 3rd resistor and the control terminal of the second switch pipe；The 7th resistance connection
Between the input terminal of the second switch pipe and the switching control end of the control module；8th resistance is connected to described
Between the input terminal of second switch pipe and the D/C voltage test side of the control module；The first end of first capacitance with it is described
The first end of second resistance connects, and the second end of first capacitance is connect with the second end of the second resistance.
4. power supply switch circuit as described in claim 1, which is characterized in that the power supply handover module includes：Switching switch
With the first diode；
The control terminal of the switching switch is connect with the switching controlled end of the power supply handover module, the input of the switching switch
End is connect with the DC power supply input terminal of the power supply handover module, the output end and the power supply handover module of the switching switch
Power output end connection；First diode is connected to the AC power input of the power supply handover module and the power supply
Between the power output end of handover module；Wherein, the AC power supplies of the anode and the power supply handover module of first diode
Input terminal connects, and the cathode of first diode is connect with the power output end of the power supply handover module.
5. power supply switch circuit as claimed in claim 4, which is characterized in that the power supply handover module further includes the two or two pole
Pipe, the second capacitance and power supply ground capacity；
Second diode be connected to output end and the power supply handover module of the switching switch power output end it
Between；Wherein, second diode anode with it is described switching switch output end connect, the cathode of second diode and
The power output end of the power supply handover module connects；The power supply of the first end of second capacitance and the power supply handover module
Output end connects, the second end ground connection of second capacitance；The first end of the power supply ground capacity and second capacitance
First end connects, the second end ground connection of the power supply ground capacity.
6. power supply switch circuit as described in claim 4 or 5, which is characterized in that the switching switch is P-channel metal-oxide-semiconductor；
The control terminal of the switching switch corresponds to the grid of the P-channel metal-oxide-semiconductor, and the input terminal of the switching switch corresponds to
The output end of the source electrode of the P-channel metal-oxide-semiconductor, the switching switch corresponds to the drain electrode of the P-channel metal-oxide-semiconductor.
7. a kind of TV power supply system, which is characterized in that including DC power module, AC-DC translation circuits, power supply switch circuit
With television operations module；
The power supply switch circuit is claim 1 to 6 any one of them power supply switch circuit；
The DC power module has DC power supply output end；The AC-DC translation circuits have DC power supply output end and for defeated
Enter the AC power input of electric main；The television operations module has power input；
The DC power supply output end of the DC power module is connect with the DC power supply input terminal of the power supply switch circuit；The AC-
The DC power supply output end of DC translation circuits is connect with the AC power input of the power supply switch circuit；The power supply switch circuit
Power output end connect with the power input of the television operations module.
8. TV power supply system as claimed in claim 7, which is characterized in that further include the DC for being connected to the DC power module
Under-voltage overvoltage crowbar between power output end and the DC power supply input terminal of the power supply switch circuit；Wherein, described to owe
Pressing through voltage protection circuit includes：Under-voltage detection unit, over-pressed detection unit and cut-off switch；
The cut-off switch has power input, switch control terminal and power output end；The overvoltage detection unit had
Press test side and over-pressed control terminal；The under-voltage detection unit has under-voltage test side and under-voltage control terminal；
The power input of the cut-off switch is connect with the DC power supply output end of the DC power module, the cut-off switch
Power output end is connect with the DC power supply input terminal of the power supply switch circuit；
The under-voltage test side of the under-voltage detection unit is connect with the power input of the cut-off switch, and the under-voltage detection is single
The under-voltage control terminal of member is connect with the switch control terminal of the cut-off switch；The over-pressed test side of the overvoltage detection unit and institute
State the power input connection of cut-off switch, the switch control of the over-pressed control terminal and the cut-off switch of the overvoltage detection unit
End connection processed.
9. TV power supply system as claimed in claim 8, which is characterized in that the under-voltage detection unit includes the first partial pressure electricity
Resistance, the second divider resistance and third switching tube；
The first end of first divider resistance is connect with the under-voltage test side of the under-voltage detection unit, the first partial pressure electricity
The second end of resistance is connect with the first end of second divider resistance；The first end of second divider resistance is opened with the third
Close the control terminal connection of pipe, the second end ground connection of second divider resistance；The input terminal of the third switching tube is owed with described
Press the under-voltage control terminal connection of detection unit, the under-voltage inspection of the input terminal of the third switching tube also with the under-voltage detection unit
Survey end connection, the output end ground connection of the third switching tube.
10. TV power supply system as claimed in claim 8, which is characterized in that it is described overvoltage detection unit include：4th switch
Pipe, third divider resistance and the 4th divider resistance；
The first end of the third divider resistance is connect with the over-pressed test side of the over-pressed detection unit, the third partial pressure electricity
The second end of resistance is connect with the control terminal of the 4th switching tube；The input terminal of 4th switching tube and the overvoltage detection are single
The over-pressed test side connection of member, the output end of the 4th switching tube are connect with the over-pressed control terminal of the over-pressed detection unit；
The first end of 4th divider resistance is connect with the second end of the third divider resistance, and the second of the 4th divider resistance
End ground connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721286753.9U CN207625292U (en) | 2017-09-29 | 2017-09-29 | Power supply switching circuit and television power supply system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721286753.9U CN207625292U (en) | 2017-09-29 | 2017-09-29 | Power supply switching circuit and television power supply system |
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| Publication Number | Publication Date |
|---|---|
| CN207625292U true CN207625292U (en) | 2018-07-17 |
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ID=62826227
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| Application Number | Title | Priority Date | Filing Date |
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| CN201721286753.9U Active CN207625292U (en) | 2017-09-29 | 2017-09-29 | Power supply switching circuit and television power supply system |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109572597A (en) * | 2018-12-27 | 2019-04-05 | 广州亚美信息科技有限公司 | A kind of intelligent switch method and power supply circuit of the power supply of OBD equipment |
-
2017
- 2017-09-29 CN CN201721286753.9U patent/CN207625292U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109572597A (en) * | 2018-12-27 | 2019-04-05 | 广州亚美信息科技有限公司 | A kind of intelligent switch method and power supply circuit of the power supply of OBD equipment |
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Effective date of registration: 20190429 Address after: 510530 3/F 310, 192 Kezhu Road, Guangzhou High-tech Industrial Development Zone, Guangdong Province Patentee after: GUANGZHOU SHIKUN ELECTRONICS Co.,Ltd. Address before: 510530 No. 6, Yun Po four road, Whampoa District, Guangzhou, Guangdong. Patentee before: Guangzhou Shiyuan Electronic Technology Company Limited |
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| TR01 | Transfer of patent right |