CN209134132U - Dual power supply switching circuit and device - Google Patents
Dual power supply switching circuit and device Download PDFInfo
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- CN209134132U CN209134132U CN201821981078.6U CN201821981078U CN209134132U CN 209134132 U CN209134132 U CN 209134132U CN 201821981078 U CN201821981078 U CN 201821981078U CN 209134132 U CN209134132 U CN 209134132U
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Abstract
A kind of dual power supply switching circuit, by the way that first switch module, second switch module, third switch module, the first current limliting module and the second current limliting module is added, it realizes when dual power supply inputs simultaneously, no matter a certain moment disconnects one of input power, circuit can work normally, and diode is replaced by using switch module, enable dual power supply switching circuit almost nil by larger current and voltage drop, solves the problems, such as that response speed present in traditional technical solution is slow, voltage drop is big and small by electric current.
Description
Technical field
The utility model belongs to electronic technology field more particularly to a kind of dual power supply switching circuit and device.
Background technique
Currently, traditional dual power supply switching circuit generally uses two diodes, using the one-way conduction of diode come
Realize the switching power supply of dual power supply, but this traditional dual power supply switching circuit response speed is slow, and due to diode sheet
Body there are the problem of, this traditional dual power supply switching circuit can have biggish pressure drop after voltage passes through and cannot be by too
High current.
Therefore, there is a problem of that response speed is slow, voltage drop is big, small by electric current in traditional technical solution.
Utility model content
In view of this, the utility model embodiment provides a kind of dual power supply switching circuit, it is intended to solve traditional technology
Voltage drop present in scheme is big, passes through electric current is small and response speed is slow problem.
The first aspect of the utility model embodiment provides a kind of dual power supply switching circuit, with the first power supply,
Two power supplys and load connection, first supply voltage are greater than the second source voltage, the dual power supply switching circuit packet
It includes:
First switch module, the first end of the first switch module are connected to first power supply, the first switch mould
Second end of block is connected to the second source, and the third of the first switch module is terminated at the defeated of the dual power supply switching circuit
Outlet, the output of the dual power supply switching circuit are terminated at the load, and the first switch module is configured as described in control
Second source arrives the on-off of the load supplying circuit and the voltage reverse irrigation for the output end for preventing the dual power supply switching circuit
The second source；
Second switch module, the first end of the second switch module are connected to first power supply, the second switch mould
The second end of block is grounded, and the second switch module, which is configured as controlling first power supply and second source, supplies the load
The on-off of circuit；
Third switch module, the first end of the third switch module are connected to the third end of the second switch module, institute
The second end for stating third switch module is connected to first power supply, and the third of the third switch module is terminated at the dual power supply
The output end of switching circuit, the third switch module are configured as controlling first power supply to the load supplying circuit
On-off and the voltage for the output end for preventing the dual power supply switching circuit flow backward to first power supply；
First current limliting module, the first end of the first current limliting module and the third end of the first switch module are connected to altogether
The output end of the dual power supply switching circuit, the third end of the second end of the first current limliting module and the second switch module
It is connected with the first end of the third switch module, the first current limliting module is configured as limiting the second switch module
The electric current of the control terminal of output end and the third switch module is to guarantee the second switch module and the third switching molding
Block works normally；
Second current limliting module, the first end of the first end of the second current limliting module and the first switch module and described
The second end of the connection of first power supply, the first end of the second current limliting module and the second switch module is connected to ground altogether, described
Second current limliting module is configured to limit the electric current of the control terminal of the first switch module to guarantee the first switch module just
Often work and avoid ground short circuit.
In one embodiment, the first switch module includes first switch tube, first diode and the two or two pole
Pipe, second diode are two-way transient supression diode, and the control terminal of the first switch tube is the first switch mould
The first end of block, the input terminal of the first switch tube are the second end of the first switch module, the first switch tube
Output end is the third end of the first switch module, the input terminal of the anode of the first diode and the first switch tube
Connection, the cathode of the first diode are connect with the output end of the first switch tube, and second diode is connected on
Between the output end and control terminal of the first switch tube.
In one embodiment, the second switch module includes second switch, the control terminal of the second switch
For the first end of the second switch module, the input terminal of the second switch is the second end of the second switch module,
The output end of the second switch is the third end of the second switch module.
In one embodiment, the third switch module includes third switching tube, third diode and the four or two pole
Pipe, the 4th diode are two-way transient supression diode, and the control terminal of the third switching tube is the third switching molding
The first end of block, the input terminal of the third switching tube are the second end of the third switch module, the third switching tube
Output end is the third end of the third switch module, the input terminal of the anode of the third diode and the third switching tube
Connection, the cathode of the third diode are connect with the output end of the third switching tube, and the 4th diode is connected on
Between the output end and control terminal of the third switching tube.
In one embodiment, the first current limliting module includes first resistor, and the first end of the first resistor is institute
The first end of the first current limliting module is stated, the second end of the first resistor is the second end of the first current limliting module.
In one embodiment, the second current limliting module includes second resistance, and the first end of the second resistance is institute
The first end of the second current limliting module is stated, the second end of the second resistance is the second end of the second current limliting module.
The second aspect of the utility model embodiment provides a kind of double-power supply switching device, with the first power supply, the second electricity
Source and load connection, first supply voltage be greater than the second source voltage, including above-mentioned dual power supply switching circuit,
First power interface circuit and second source interface circuit, the dual power supply switching circuit is through first power interface circuit
It is connected to first power supply, the dual power supply switching circuit is connected to the second source through the second source interface circuit.
In one embodiment, first power interface circuit includes round end interface or contact pin interface.
In one embodiment, the second source interface circuit includes USB interface.
In one embodiment, the double-power supply switching device further includes capacitor, and the first end of the capacitor is born with described
Carry connection, the second end ground connection of the capacitor.
Above-mentioned dual power supply switching circuit, by be added first switch module, second switch module, third switch module,
First current limliting module and the second current limliting module realize when dual power supply inputs simultaneously no matter to disconnect one of them defeated a certain moment
Enter power supply, circuit can work normally, and replace diode by using switch module, and dual power supply switching circuit is led to
It crosses larger current and voltage drop is almost nil, solve that response speed present in traditional technical solution is slow, voltage pressure
Drop is big, passes through the small problem of electric current.
Detailed description of the invention
It, below will be to embodiment or the prior art in order to illustrate more clearly of the technical scheme in the embodiment of the utility model
Attached drawing needed in description is briefly described, it should be apparent that, the accompanying drawings in the following description is only that this is practical new
Some embodiments of type for those of ordinary skill in the art without any creative labor, can be with
It obtains other drawings based on these drawings.
Fig. 1 is the circuit diagram for the dual power supply switching circuit that an embodiment of the present invention provides；
Fig. 2 is the exemplary circuit schematic diagram of first switch module in dual power supply switching circuit shown in FIG. 1；
Fig. 3 is the exemplary circuit schematic diagram of second switch module in dual power supply switching circuit shown in FIG. 1；
Fig. 4 is the exemplary circuit schematic diagram of third switch module in dual power supply switching circuit shown in FIG. 1；
Fig. 5 is the exemplary circuit schematic diagram of the first current limliting module in dual power supply switching circuit shown in FIG. 1；
Fig. 6 is the exemplary circuit schematic diagram of the second current limliting module in dual power supply switching circuit shown in FIG. 1；
Fig. 7 is the detailed circuit schematic for the dual power supply switching circuit that an embodiment of the present invention provides；
Fig. 8 is the circuit diagram for the double-power supply switching device that an embodiment of the present invention provides；
Fig. 9 is the circuit diagram for the double-power supply switching device that another embodiment of the utility model provides.
Specific embodiment
In order to make the purpose of the utility model, technical solutions and advantages more clearly understood, below in conjunction with attached drawing and implementation
Example, the present invention will be further described in detail.It should be appreciated that specific embodiment described herein is only used to explain
The utility model is not used to limit the utility model.
Referring to Fig. 1, the circuit diagram for the dual power supply switching circuit that the utility model first embodiment provides, in order to just
In explanation, only the parts related to this embodiment are shown, and details are as follows:
In one embodiment, dual power supply switching circuit and the first power supply 100, second source 200 and load 300 connect
It connects, 100 voltage of the first power supply is greater than 200 voltage of second source, it should be appreciated that in order to guarantee that circuit works normally, the first power supply 100
Voltage and 200 voltage difference of second source are at least in 1.2V or more.
Dual power supply switching circuit includes first switch module 410, second switch module 420, third switch module 430,
One current limliting module 440 and the second current limliting module 450, wherein first switch module 410 is configured as control second source 200
The on-off of 300 power supply circuits of load and the voltage for the output end for preventing dual power supply switching circuit are flowed backward to first switch module
410, first switch module 410 can by have on-off function, pass through after do not have it is voltage drop, fast response time and
The switching tube or integrated circuit of reverse-filling function are constituted, such as LP2301ELT1G series metal-oxide-semiconductor；420 quilt of second switch module
It is configured to the on-off of the first power supply 100 of control and 200 pairs of second source 300 power supply circuits of load, second switch module 420 can be with
By have on-off function, pass through after there is no voltage drop and fast response time switching tube or integrated circuit to constitute,
Such as LN2306LT1G series metal-oxide-semiconductor；Third switch module 430 is configured as 100 pairs of the first power supply loads of control, 300 power supply electricity
The on-off on road and the voltage for the output end for preventing dual power supply switching circuit flow backward to the first power supply 100, and third switch module 430 can
With by have on-off function, pass through after do not have voltage drop, fast response time and reverse-filling function switching tube or
Person's integrated circuit is constituted, such as LP2301ELT1G series metal-oxide-semiconductor；First current limliting module 440 is configured as limitation second switch mould
The electric current of the control terminal of the output end and third switch module 430 of block 420 is to guarantee second switch module 420 and third switching molding
Block 430 works normally the second current limliting module 450 and is configured to limit the electric current of the control terminal of first switch module 410 to guarantee first
Switch module 410 works normally and avoids ground short circuit, and the first current limliting module 440 and the second current limliting module 450 can be by having
The component of standby metering function forms, such as resistance.
First end of first switch module 410 is connected to the first power supply 100, and the second end of first switch module 410 is connected to
The third of two power supplys 200, first switch module 410 is terminated at the output end of dual power supply switching circuit, dual power supply switching circuit
Output is terminated at load 300, second switch module 420, and the first end of second switch module 420 is connected to the first power supply 100, and second
The second end of switch module 420 is grounded, and the first end of third switch module 430, third switch module 430 is connected to second switch mould
The third end of block 420, the second end of third switch module 430 are connected to the first power supply 100, the third end of third switch module 430
It is connected to the output end of dual power supply switching circuit, the first current limliting module 440, the first end and first switch of the first current limliting module 440
The third end of module 410 is connected to the output end of dual power supply switching circuit, the second end and second switch of the first current limliting module 440 altogether
The third end of module 420 is connected with the first end of third switch module 430, the second current limliting module 450, the second current limliting module 450
First end connect with the first end of first switch module 410 and the first power supply 100, the first end of the second current limliting module 450 with
The second end of second switch module 420 is connected to ground altogether.
Dual power supply switching circuit in the present embodiment, by be added first switch module 410, second switch module 420,
Third switch module 430, the first current limliting module 440 and the second current limliting module 450, realize when dual power supply simultaneously input when no matter
The a certain moment disconnects one of input power, and circuit can work normally, and replaces diode by using switch module,
Enable dual power supply switching circuit almost nil by larger current and voltage drop, solves and deposited in traditional technical solution
Response speed is slow, voltage drop is big, passes through the small problem of electric current.
In one embodiment, referring to Fig. 2, first switch module 410 includes switching tube Q1, diode D1 and two-way
The control terminal of transient supression diode D2, switching tube Q1 are the first end of first switch module 410, and the input terminal of switching tube Q1 is
The second end of first switch module 410, the output end of switching tube Q1 are the third end of first switch module 410, diode D1's
Anode is connect with the input terminal of switching tube Q1, and the cathode of diode D1 is connect with the output end of switching tube Q1, two-way transient supression
Diode D2's is connected between the output end and control terminal of switching tube Q1.
Referring to Fig. 3, second switch module 420 includes switching tube Q2, the control terminal of switching tube Q2 is second switch module
420 first end, the input terminal of switching tube Q2 are the second end of second switch module 420, and the output end of switching tube Q2 is second
The third end of switch module 420.
Referring to Fig. 4, third switch module 430 includes switching tube Q3, diode D3 and two-way transient supression diode
The control terminal of D4, switching tube Q3 are the first end of third switch module 430, and the input terminal of switching tube Q3 is third switch module
430 second end, the output end of switching tube Q3 are the third end of third switch module 430, the anode and switching tube of diode D3
The input terminal of Q3 connects, and the cathode of diode D3 is connect with the output end of switching tube Q3, two-way transient supression diode D4 series connection
Between the output end and control terminal of switching tube Q3.
Switching tube specifically can be the three terminal type transistor with control terminal, input terminal and output end, for example, positive-negative-positive
Triode, NPN type triode, metal-oxide-semiconductor or IGBT thyristor etc., the control terminal of switching tube are triode/metal-oxide-semiconductor/IGBT brilliant
Base stage/grid of brake tube, the input terminal of switching tube are triode/metal-oxide-semiconductor/IGBT thyristor collector, switching tube
Output end is triode/metal-oxide-semiconductor/IGBT thyristor emitter/source electrode.
Referring to Fig. 5, the first current limliting module 440 includes resistance R1, the first end of resistance R1 is the first current limliting module 440
First end, the second end of resistance R1 are the second end of the first current limliting module 440.
Referring to Fig. 6, the second current limliting module 450 includes resistance R2, the first end of resistance R2 is the second current limliting module 450
First end, the second end of resistance R2 are the second end of the second current limliting module 450.
Referring to Fig. 7, in order to make it easy to understand, in one embodiment, with one of them specific dual power supply switching circuit
For, sketch the working method of dual power supply switching circuit, wherein the first supply voltage is 9V, second voltage 5V, switching tube Q1
It is PMOS tube with switching tube Q3, switching tube Q2 is NMOS tube.
When only VDD_5V has input power, the G of switching tube Q1 extremely low level at this time, switching tube Q1 is fully on, this
When, VDD_IN=VDD_5V, and Q2 and Q3 cut-off, VDD_IN voltage cannot flow backward to VDD_9V.
When only VDD_9V has input power, switching tube Q2 is connected at this time, and then the G of switching tube Q3 extremely low level,
To which switching tube Q3 is in fully on state, last VDD_IN=VDD_9V, and switching tube Q1 is in off state, VDD_IN
Voltage can not be filled to VDD_5V.
When VDD_5V and VDD_9V are inputted simultaneously, switching tube Q1 cut-off, switching tube Q2 and switching tube Q3 are in the conductive state,
And the S pole tension of switching tube Q1 is higher than D pole tension, simultaneously as the presence of diode D1, therefore last VDD_IN=VDD_9V,
And VDD_IN voltage can not also flow backward to VDD_5V, to ensure the safety of circuit, VDD_5V and VDD_9V are inputted simultaneously, nothing
One of input power is disconnected by a certain moment, system can work normally, and when disconnecting VDD_5V input power, output is then
For VDD_9V, and when disconnecting VDD_9V input power, output is then VDD_5V.
It is defeated that dual power supply switching circuit in the present embodiment is able to satisfy high current, voltage while realizing dual power supply seamless switching
Enter the demand for exporting no pressure drop, high conversion efficiency and fast response time.
Referring to Fig. 8, the second embodiment of the utility model provides a kind of double-power supply switching device, with the first power supply
100, second source 200 and load connection, 100 voltage of the first power supply are greater than 200 voltage of second source, including above-mentioned double electricity
Source switching circuit 400, the first power interface circuit 500 and second source interface circuit 600, the first power interface circuit 500
Round end interface or contact pin interface can be used, second source interface circuit 600 can use USB interface, dual power supply switching circuit
400 are connected to the first power supply 100 through the first power interface circuit 500, and dual power supply switching circuit connects through second source interface circuit 600
In second source 200.
Referring to Fig. 9, in one embodiment, double-power supply switching device further includes capacitor C1, the first end of capacitor C1 with
300 connection of load, the second end ground connection of capacitor C1, it is to be understood that the characteristic of voltage jump can not be carried out according to capacitor C1,
Power switch switching is completed before its load capacitance C1 completion has been discharged, and is realized in dual power supply handoff procedure, after not causing
End system power-off.
The only preferred embodiment for the utility model above, is not intended to limit the utility model, all at this
Made any modifications, equivalent replacements, and improvements etc., should be included in the utility model within the spirit and principle of utility model
Protection scope within.
Claims (10)
1. a kind of dual power supply switching circuit, which is characterized in that connected with the first power supply, second source and load, described first
Supply voltage is greater than the second source voltage, and the dual power supply switching circuit includes:
First switch module, the first end of the first switch module are connected to first power supply, the first switch module
Second end is connected to the second source, and the third of the first switch module is terminated at the output of the dual power supply switching circuit
End, the output of the dual power supply switching circuit are terminated at the load, and the first switch module is configured as controlling described the
Two power supplys flow backward to institute the on-off of the load supplying circuit and the voltage for the output end for preventing the dual power supply switching circuit
State second source；
Second switch module, the first end of the second switch module are connected to first power supply, the second switch module
Second end ground connection, the second switch module are configured as controlling first power supply and second source to the load supplying electricity
The on-off on road；
Third switch module, the first end of the third switch module are connected to the third end of the second switch module, and described
Second end of three switch modules is connected to first power supply, and the third of the third switch module is terminated at the dual power supply switching
The output end of circuit, the third switch module are configured as controlling first power supply to the on-off of the load supplying circuit
Flow backward with the voltage for the output end for preventing the dual power supply switching circuit to first power supply；
The third end of first current limliting module, the first end of the first current limliting module and the first switch module is connected to described altogether
The third end of the output end of dual power supply switching circuit, the second end of the first current limliting module and the second switch module and institute
The first end connection of third switch module is stated, the first current limliting module is configured as limiting the output of the second switch module
The electric current of the control terminal of end and the third switch module is to guarantee the second switch module and the third switch module just
Often work；
Second current limliting module, the first end and described first of the first end of the second current limliting module and the first switch module
Power supply connection, the second end of the first end of the second current limliting module and the second switch module are connected to ground altogether, and described second
Current limliting module is configured to limit the electric current of the control terminal of the first switch module to guarantee the normal work of first switch module
Make and avoid ground short circuit.
2. dual power supply switching circuit as described in claim 1, which is characterized in that the first switch module includes first switch
Pipe, first diode and the second diode, second diode are two-way transient supression diode, the first switch tube
Control terminal be the first switch module first end, the input terminal of the first switch tube is the first switch module
Second end, the output end of the first switch tube are the third end of the first switch module, the anode of the first diode
It is connect with the input terminal of the first switch tube, the output end of the cathode of the first diode and the first switch tube connects
It connects, second diode is connected between the output end and control terminal of the first switch tube.
3. dual power supply switching circuit as described in claim 1, which is characterized in that the second switch module includes second switch
Pipe, the control terminal of the second switch are the first end of the second switch module, and the input terminal of the second switch is
The second end of the second switch module, the output end of the second switch are the third end of the second switch module.
4. dual power supply switching circuit as described in claim 1, which is characterized in that the third switch module includes third switch
Pipe, third diode and the 4th diode, the 4th diode are two-way transient supression diode, the third switching tube
Control terminal be the third switch module first end, the input terminal of the third switching tube is the third switch module
Second end, the output end of the third switching tube are the third end of the third switch module, the anode of the third diode
It is connect with the input terminal of the third switching tube, the output end of the cathode of the third diode and the third switching tube connects
It connects, the 4th diode is connected between the output end and control terminal of the third switching tube.
5. dual power supply switching circuit as described in claim 1, which is characterized in that the first current limliting module includes the first electricity
Resistance, the first end of the first resistor are the first end of the first current limliting module, and the second end of the first resistor is described
The second end of first current limliting module.
6. dual power supply switching circuit as described in claim 1, which is characterized in that the second current limliting module includes the second electricity
Resistance, the first end of the second resistance are the first end of the second current limliting module, and the second end of the second resistance is described
The second end of second current limliting module.
7. a kind of double-power supply switching device, which is characterized in that connected with the first power supply, second source and load, described first
Supply voltage is greater than the second source voltage, including dual power supply switching circuit as claimed in any one of claims 1 to 6, first
Power interface circuit and second source interface circuit, the dual power supply switching circuit are connected to through first power interface circuit
First power supply, the dual power supply switching circuit are connected to the second source through the second source interface circuit.
8. double-power supply switching device as claimed in claim 7, which is characterized in that first power interface circuit includes round end
Interface or contact pin interface.
9. double-power supply switching device as claimed in claim 7, which is characterized in that the second source interface circuit includes USB
Interface.
10. double-power supply switching device as claimed in claim 7, which is characterized in that it further include capacitor, the first end of the capacitor
It is connected to the load, the second end ground connection of the capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821981078.6U CN209134132U (en) | 2018-11-28 | 2018-11-28 | Dual power supply switching circuit and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821981078.6U CN209134132U (en) | 2018-11-28 | 2018-11-28 | Dual power supply switching circuit and device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209134132U true CN209134132U (en) | 2019-07-19 |
Family
ID=67247214
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201821981078.6U Active CN209134132U (en) | 2018-11-28 | 2018-11-28 | Dual power supply switching circuit and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209134132U (en) |
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2018
- 2018-11-28 CN CN201821981078.6U patent/CN209134132U/en active Active
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