CN205489449U - Power supply circuit - Google Patents
Power supply circuit Download PDFInfo
- Publication number
- CN205489449U CN205489449U CN201620018859.XU CN201620018859U CN205489449U CN 205489449 U CN205489449 U CN 205489449U CN 201620018859 U CN201620018859 U CN 201620018859U CN 205489449 U CN205489449 U CN 205489449U
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- circuit
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- resistance
- power supply
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Abstract
The utility model discloses a power supply circuit, include switching power supply and fall the circuit fast, switching power supply includes source transformation circuit and power control chip, the output of source transformation circuit is connected power control chip's power input end, it includes discharge circuit and detection circuitry to fall the circuit fast, the discharge circuit includes the discharge end and puts the electrical signal input end, detection circuitry includes the sense terminal and puts electrical signal output terminal, the sense terminal with the input of source transformation circuit all is connected to the alternating -current power supply, it connects to put electrical signal output terminal put the electrical signal input end, the discharge end is connected the output of source transformation circuit. The utility model provides a detection circuitry is detecting alternating -current power supply outage back, sends the signal that discharges and gives the discharge circuit, makes the discharge circuit discharge to the source transformation circuit to guarantee the power rapid stop work of switching power supply shutdown back, and it is this circuit structure is simple, with low costs.
Description
Technical field
This utility model relates to electronic technology field, particularly relates to a kind of power circuit.
Background technology
In all kinds of switching power circuits, owing to big electrochemical capacitor exists, after Switching Power Supply shutdown, power supply meeting
Work on a period of time, output band carry compared with light or the most unloaded time the output voltage retention time oversize.This meeting
Cause power supply output LED light or the equipment (example television set, display, audio amplifier etc.) being connected with power supply
Display lamp is delay-action after Switching Power Supply is shut down.
In order to after making Switching Power Supply shutdown, power supply quickly quits work, a kind of input undervoltage is the most generally used to protect
Protecting chip, this chip can make electricity by the output of deenergization control chip after Switching Power Supply is shut down
Source quickly quits work, but said chip is relatively costly.
Utility model content
Technical problem to be solved in the utility model is, it is provided that a kind of power circuit, is ensureing switch electricity
In the case of power supply quickly quits work after the shutdown of source, reduce cost.
In order to solve above-mentioned technical problem, this utility model provides a kind of power circuit, including Switching Power Supply
With quick down circuit；
Described Switching Power Supply includes power converting circuit and power supply control chip, described power converting circuit defeated
Entering end and connect alternating-current power supply, the outfan of described power converting circuit connects the electricity of described power supply control chip
Source input；
Described quick down circuit includes discharge circuit and testing circuit；
Described discharge circuit includes discharge end and discharge signal input；
Described testing circuit includes test side and discharge signal outfan；
Described test side connects alternating-current power supply, and described discharge signal outfan connects the input of described discharge signal
End, described discharge end connects the outfan of described power converting circuit.
Further, described testing circuit also include the first resistance, the second resistance, the 3rd resistance, electric capacity and
Diode；
The test side that first end is described testing circuit of described first resistance, the second end of described first resistance
Connect the first end of described second resistance, the second end ground connection of described second resistance, the first end of described electric capacity
Connect the first end of described second resistance, the second end ground connection of described electric capacity, the first end of described 3rd resistance
Connecting the first end of described electric capacity, the second end of described 3rd resistance connects the positive pole of described diode, described
The discharge signal outfan of the most described testing circuit of diode, the negative pole of described diode connects described
First end of the 3rd resistance.
Further, described discharge circuit also includes switching tube and the 4th resistance；
The end that controls of described switching tube is the discharge signal input of described discharge circuit, the of described switching tube
Second end of described 4th resistance of one end connection, the second end ground connection of described switching tube, described 4th resistance
First end is the discharge end of described discharge circuit.
Preferably, described switching tube is PNP type triode, and the transmitting of described PNP type triode is extremely described
First end of switching tube, the second end of the most described switching tube of current collection of described PNP type triode, described PNP
The base stage of type audion is the control end of described switching tube.
The power circuit that this utility model provides, detects alternating current input signal by testing circuit, works as detection
During to alternating-current power supply power-off, testing circuit sends discharge signal and receives this put to discharge circuit, discharge circuit
After the signal of telecommunication discharging power converting circuit, in discharge process, the electricity of power converting circuit output is fast
Prompt drop is low, falls below the closedown voltage of power supply control chip, and power supply control chip quits work, thus
After ensure that Switching Power Supply shutdown, power supply quickly quits work, and this circuit structure is simple, low cost.
Accompanying drawing explanation
Fig. 1 is the circuit block diagram of a kind of power circuit that this utility model provides；
Fig. 2 is the circuit theory diagrams of an embodiment of a kind of power circuit that this utility model provides.
Detailed description of the invention
Below in conjunction with the accompanying drawing in this utility model embodiment, to the technical side in this utility model embodiment
Case is clearly and completely described, it is clear that described embodiment is only that this utility model part is real
Execute example rather than whole embodiments.Based on the embodiment in this utility model, ordinary skill people
The every other embodiment that member is obtained under not making creative work premise, broadly falls into this utility model
The scope of protection.
See Fig. 1, be the circuit block diagram of a kind of power circuit that this utility model provides.
This utility model embodiment provides a kind of power circuit, including Switching Power Supply 1 and quick down circuit 2；
Described Switching Power Supply 1 includes power converting circuit 4 and power supply control chip 3, described power converting circuit
The input a of 4 connects alternating-current power supply, and the outfan b of described power converting circuit 4 connects described power supply control
The power input VCC of coremaking sheet 3；
Described quick down circuit 2 includes discharge circuit 6 and testing circuit 5；
Described discharge circuit 6 includes discharge end g and discharge signal input f；
Described testing circuit 5 includes test side d and discharge signal outfan e；
Described test side d connects alternating-current power supply, and described discharge signal outfan e connects described discharge signal
Input f, described discharge end g connect the outfan b of described power converting circuit 4.
In the specific implementation, alternating current input signal is detected by testing circuit 5, when testing circuit 5 is examined
When measuring alternating-current power supply power-off, testing circuit 5 sends discharge signal and receives to discharge circuit 6, discharge circuit 6
After this discharge signal, power converting circuit 4 is discharged, in discharge process, power converting circuit 4
Output electricity quickly reduces, and when falling below the closedown voltage of power supply control chip 3, power supply controls core
Sheet 3 quits work, thus after ensure that Switching Power Supply 1 shutdown, power supply quickly quits work.
See Fig. 2, be the circuit theory diagrams of an embodiment of a kind of power circuit that this utility model provides.
As in figure 2 it is shown, testing circuit 5 also includes the first resistance R1, the second resistance R2, the 3rd resistance R3, electricity
Hold C and diode D；
The test side d that first end is testing circuit 5 of described first resistance R1, described first resistance R1's
Second end connects first end of the second resistance R2, the second end ground connection of described second resistance R2, described electric capacity
First end of C connects first end of the second resistance R2, the second end ground connection of described electric capacity C, described 3rd electricity
First end of resistance R3 connects first end of electric capacity C, and second end of described 3rd resistance R3 connects diode D
Positive pole, the discharge signal outfan e of the most extremely testing circuit 5 of described diode D, described diode D
Negative pole connect the 3rd resistance R3 the first end.
Wherein, the work process of testing circuit 5 is as follows: when the test side d of testing circuit 5 detects exchange
When electricity power supply normally works, the first resistance R1 and the second resistance R2 is right after AC-input voltage is carried out dividing potential drop
Electric capacity C is charged, and forms a DC voltage at the two ends of electric capacity C；Test side when testing circuit 5
When d detects alternating-current power supply power-off, electric capacity C is discharged by the second resistance R2, in discharge process,
The voltage at electric capacity C two ends is gradually lowered, and then provides an electric discharge by the 3rd resistance R3 for discharge circuit 6
Voltage signal.The characteristic that diode forward pressure drop is less and is basically unchanged, diode D is utilized to play herein
Accelerate the effect of discharge voltage signal output；Utilizing electric capacity to lead to the characteristic of exchange stopping direct current, electric capacity C is herein
Play the effect of filtering.
Further, discharge circuit 6 also includes switching tube Q and the 4th resistance R4；
Described switching tube Q controls the discharge signal input f, described switching tube Q that end is discharge circuit 6
First end connect the 4th resistance R4 the second end, the second end ground connection of described switching tube Q, described 4th electricity
The discharge end g that first end is discharge circuit 6 of resistance R4.
In the present embodiment, described switching tube Q is PNP type triode, the emitter stage of described PNP type triode
For first end of switching tube Q, second end of the current collection of described PNP type triode extremely switching tube Q, described
The base stage of PNP type triode is the control end of switching tube Q.Discharge circuit operation principle is: discharge circuit 6
Discharge signal input f receive discharge signal after, switching tube Q turns on, and discharge circuit 6 is by the 4th electricity
Power converting circuit 4 is discharged by resistance R4.
It should be noted that in the power circuit of above-described embodiment offer, switching tube Q is PNP type triode,
Being only a kind of embodiment therein, in other embodiments, switching tube Q may be replaced by NPN
Type audion or other three ports for control switching device or its derive from device, in different application scenarios, regard reality
The power consumption of border circuit, cost, driving power and the driving with switching tube control the requirements such as component parameter matching
Reasonable selection and setting, select and arrange the conventional design process that switching tube is prior art, not carrying out at this
Repeat.
The power circuit that this utility model provides, detects alternating current input signal by testing circuit, works as detection
During to alternating-current power supply power-off, testing circuit sends discharge signal and receives this put to discharge circuit, discharge circuit
After the signal of telecommunication discharging power converting circuit, in discharge process, the electricity of power converting circuit output is fast
Prompt drop is low, falls below the closedown voltage of power supply control chip, and power supply control chip quits work, thus
After ensure that Switching Power Supply shutdown, power supply quickly quits work, and this circuit structure is simple, low cost.
The above is the preferred embodiment of the present invention, it is noted that for the common skill of the art
For art personnel, under the premise without departing from the principles of the invention, it is also possible to make some improvement and deformation, this
A little improvement and deformation are also considered as protection scope of the present invention.
Claims (2)
1. a power circuit, it is characterised in that include Switching Power Supply and quick down circuit；
Described Switching Power Supply includes power converting circuit and power supply control chip, and the input of described power converting circuit connects alternating-current power supply, and the outfan of described power converting circuit connects the power input of described power supply control chip；
Described quick down circuit includes discharge circuit and testing circuit；
Described discharge circuit includes discharge end and discharge signal input；
Described testing circuit includes test side and discharge signal outfan；
Described test side connects alternating-current power supply, and described discharge signal outfan connects described discharge signal input, and described discharge end connects the outfan of described power converting circuit；
Described testing circuit also includes the first resistance, the second resistance, the 3rd resistance, electric capacity and diode；
The test side that first end is described testing circuit of described first resistance, second end of described first resistance connects the first end of described second resistance, second end ground connection of described second resistance, first end of described electric capacity connects the first end of described second resistance, second end ground connection of described electric capacity, first end of described 3rd resistance connects the first end of described electric capacity, second end of described 3rd resistance connects the positive pole of described diode, the discharge signal outfan of the most described testing circuit of described diode, the negative pole of described diode connects the first end of described 3rd resistance；
Described discharge circuit also includes switching tube and the 4th resistance；
The discharge signal input that control end is described discharge circuit of described switching tube, the first end of described switching tube connects the second end of described 4th resistance, the second end ground connection of described switching tube, the discharge end that the first end is described discharge circuit of described 4th resistance.
2. power circuit as claimed in claim 1, it is characterized in that, described switching tube is PNP type triode, first end of the most described switching tube of transmitting of described PNP type triode, second end of the most described switching tube of current collection of described PNP type triode, the base stage of described PNP type triode is the control end of described switching tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620018859.XU CN205489449U (en) | 2016-01-07 | 2016-01-07 | Power supply circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620018859.XU CN205489449U (en) | 2016-01-07 | 2016-01-07 | Power supply circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205489449U true CN205489449U (en) | 2016-08-17 |
Family
ID=56665286
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201620018859.XU Active CN205489449U (en) | 2016-01-07 | 2016-01-07 | Power supply circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205489449U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106655724A (en) * | 2016-11-03 | 2017-05-10 | 广州视源电子科技股份有限公司 | Power switch circuit |
-
2016
- 2016-01-07 CN CN201620018859.XU patent/CN205489449U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106655724A (en) * | 2016-11-03 | 2017-05-10 | 广州视源电子科技股份有限公司 | Power switch circuit |
| CN106655724B (en) * | 2016-11-03 | 2018-12-07 | 广州视源电子科技股份有限公司 | A kind of power switch circuit |
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| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |