CN205430080U - Flyback circuit - Google Patents
Flyback circuit Download PDFInfo
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- CN205430080U CN205430080U CN201520905725.5U CN201520905725U CN205430080U CN 205430080 U CN205430080 U CN 205430080U CN 201520905725 U CN201520905725 U CN 201520905725U CN 205430080 U CN205430080 U CN 205430080U
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- output
- circuit
- outfan
- protection circuit
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Abstract
The utility model relates to an electronic circuit technical field, in particular to flyback circuit, including transformer, MOS pipe, protection circuit and filtering unit. The coiler part of transformer comprises primary, a secondary coil and the 2nd secondary coil. A secondary coil's the one end and the source connection of MOS pipe, not another termination output ground. The drain electrode of MOS pipe is connected with the one end of filtering unit, and ground is exported by another termination of filtering unit. The grid of MOS pipe is connected with the output of protection circuit, and the protection circuit still is not connected with input ground and output ground respectively. The 2nd secondary coil's one end is connected with the input of protection circuit, another termination input ground. The one end and the one end of voltage output port of filtering unit are connected, and the other end and the other end of voltage output port of filtering unit are connected. The embodiment of the utility model provides a flyback circuit, the signal of control MOS pipe switch is the same with the phase place of the PWM ripples of secondary coil output for flyback circuit's phase synchronization is and have stable voltage output.
Description
Technical field
This utility model relates to electronic circuit technology field, particularly to a kind of Flyback circuit.
Background technology
At present, Flyback structure is with extensively, and its reason has: from the point of view of circuit, and Flyback circuit has the feature of minimum element；From the point of view of design, the feature that Flyback circuit has simple in construction, reliability is high；From the point of view of economy, Flyback circuit cost is relatively low, is suitable for small-power power and uses.In prior art, Linear company is that the Flyback structure application of representative is relatively broad, this Flyback structure comprises 2 transformators (i.e. transformator one and transformator two), the secondary output of transformator one comprises 2 coils, one coil output uses MOSFET to substitute conventional diode and realizes halfwave rectifier function, output voltage after electric capacity after filtering, another coil regulates output stability as the feedback signal of output voltage, PWM (the Pulse-WidthModulation that Linear chip produces, pulsewidth modulation) ripple through transformator two isolate after, for controlling the switch of this MOSFET.Flyback structure with Linear company as representative, MOSFET opens or closing control signal is that extra PWM ripple provides, inconsistent with the PWM ripple signal source in secondary coil, the nonsynchronous problem of phase place existed, affect output and the power supply stability of rectified signal, stable voltage output will be reached, need to control phase place, add complexity and the cost of circuit, and be difficult to completely the same.Additionally, due to add second transformator, area occupied becomes big, and cost increases.
Utility model content
This utility model embodiment, by providing a kind of Flyback circuit, solves that Flyback current phase in prior art is asynchronous and the technical problem of the poor stability of signal output so that the Phase synchronization of Flyback circuit and have stable voltage output.
This utility model embodiment provides a kind of Flyback circuit, including: transformator, metal-oxide-semiconductor, protection circuit and filter unit.
The coiler part of described transformator is made up of primary coil, the first secondary coil and second subprime coil；The two ends of described primary coil are first input end and the second input, and described first input end and described second input are used for inputting PWM ripple signal.
The two ends of described first secondary coil are the first outfan and the second outfan, and described first outfan is connected with the source electrode of described metal-oxide-semiconductor, described second output termination output ground；The drain electrode of described metal-oxide-semiconductor is connected with one end of described filter unit, another termination described output ground of described filter unit；The grid of described metal-oxide-semiconductor is connected with the outfan of described protection circuit, and described protection circuit is connected with described the most respectively with inputting ground and described output.
The two ends of described second subprime coil are the 3rd outfan and the 4th outfan；Described 3rd outfan is connected with the input of described protection circuit, described 4th output termination input ground.
One end of described filter unit is connected with one end of voltage output end mouth, and the other end of described filter unit is connected with the other end of described voltage output end mouth, and described voltage output end mouth is total output interface of described Flyback circuit.
Further, described iron core is bar-shaped iron core.
Further, described primary coil and described second subprime coil are arranged on the same side of described iron core, and described first secondary coil is arranged on the opposite side of described iron core；Described second subprime coil is arranged on the lower section of described primary coil.
Further, described metal-oxide-semiconductor is NMOS tube or PMOS.
Further, described protection circuit is light-coupled isolation protection circuit.
Further, described filter unit is filter capacitor.
One or more technical schemes that this utility model embodiment provides, at least possess following beneficial effect or advantage:
1, the Flyback circuit that this utility model embodiment provides, the phase place of the PWM ripple controlling signal and the first secondary coil output of metal-oxide-semiconductor switch is identical so that the Phase synchronization of Flyback circuit and have stable voltage and export.The Flyback circuit that this utility model embodiment provides, the feedback signal utilizing transformator second subprime coil controls the switch of metal-oxide-semiconductor, circuit structure design is ingenious, and the secondary output of transformator only needs two coils, without customizing special transformator, it is not take up more area, reduces production cost.
2, the Flyback circuit that this utility model embodiment provides, utilizes metal-oxide-semiconductor to carry out rectification, and conversion efficiency is high, it is possible to provide bigger electric current and support bigger power output.
3, the Flyback circuit that this utility model embodiment provides, metal-oxide-semiconductor can use NMOS tube or PMOS, and the selection range of metal-oxide-semiconductor is wide.
4, the Flyback circuit that this utility model embodiment provides, protection circuit uses light-coupled isolation protection circuit, and isolation effect is good, can be prevented effectively from the crosstalk between signal.
5, the Flyback circuit that this utility model embodiment provides, filter unit uses filter capacitor, and the simple in construction of filter capacitor, cost are relatively low, are provided simultaneously with preferable filter effect, on the premise of ensureing Flyback circuit filtering effect, reduces production cost.
Accompanying drawing explanation
The Flyback electrical block diagram that Fig. 1 provides for this utility model embodiment；
Fig. 2 for the input voltage that this utility model embodiment provides be 54V, output voltage be the transformer device structure schematic diagram of 12V；
Fig. 3 for the input voltage that this utility model embodiment provides be 90～265V, output voltage be the transformer device structure schematic diagram of 55V.
Detailed description of the invention
This utility model embodiment, by providing a kind of Flyback circuit, solves that Flyback current phase in prior art is asynchronous and the technical problem of the poor stability of signal output so that the Phase synchronization of Flyback circuit and have stable voltage output.
Seeing Fig. 1, this utility model embodiment provides a kind of Flyback circuit, including: transformator, metal-oxide-semiconductor, protection circuit and filter unit.In this utility model embodiment, metal-oxide-semiconductor is NMOS tube or PMOS, and protection circuit is light-coupled isolation protection circuit, and filter unit is filter capacitor.
Seeing Fig. 1, the coiler part of transformator is made up of iron core, primary coil L1, the first secondary coil L2 and second subprime coil L3, and in this utility model embodiment, iron core is bar-shaped iron core.Primary coil L1 and second subprime coil L3 is arranged on the same side of iron core, and the first secondary coil L2 is arranged on the opposite side of iron core, and second subprime coil L3 is arranged on the lower section of primary coil L1.The two ends of primary coil L1 are respectively first input end 1 and the second input 2, and first input end 1 and the second input 2 are used for inputting PWM (Pulse-WidthModulation, pulsewidth modulation) ripple signal.
Seeing Fig. 1, the two ends of the first secondary coil L2 are respectively first outfan the 3, second outfan 4, and the first outfan 3 is connected with the source electrode of metal-oxide-semiconductor Q, and the second outfan 4 meets output ground GND2.The drain electrode of metal-oxide-semiconductor Q is connected with one end of filter capacitor C, another termination output ground GND2 of filter capacitor C.The grid of metal-oxide-semiconductor Q is connected with the outfan of light-coupled isolation protection circuit 9, and light-coupled isolation protection circuit 9 is connected with input ground GND1 and output ground GND2 the most respectively.Light-coupled isolation protection circuit 9 plays insulation blocking and pulses switch effect.
Seeing Fig. 1, the two ends of second subprime coil L3 are respectively the 3rd outfan the 5, the 4th outfan 6.3rd outfan 5 is connected with the input of light-coupled isolation protection circuit 9, and the 4th outfan 6 meets input ground GND1.
See Fig. 1, one end of filter capacitor C is connected with one end (i.e. port 7) of voltage output end mouth, the other end of filter capacitor C is connected with the other end (i.e. port 8) of voltage output end mouth, voltage output end mouth is total output interface of Flyback circuit, for external miscellaneous equipment.
See Fig. 1, in actual applications, primary coil L1, the first secondary coil L2 and the turn ratio of second subprime coil L3 can be set according to the input of transformator, being actually needed of output voltage.As: seeing Fig. 2, the input voltage of transformator is 54V, output voltage is 12V, and arranging turn ratio (primary coil the L1: the first secondary coil L2: second subprime coil L3) is 1:0.35:0.35.Seeing Fig. 3, the input voltage of transformator is 90～265V, output voltage is 55V, and arranging turn ratio (primary coil the L1: the first secondary coil L2: second subprime coil L3) is 2:1:0.4.
The operation principle of the Flyback circuit that this utility model embodiment provides is as follows:
As a example by NMOS tube, see Fig. 1, PWM ripple as the first input end 1 of primary coil L1 and the input signal of second input 2 of primary coil L1.Second outfan 4 of the first secondary coil L2 connects output ground GND2, first outfan 3 of the first secondary coil L2 connects the source electrode of NMOS tube Q, certainly the source electrode of NMOS tube Q can also be connected to second outfan 4 of the first secondary coil L2, the first outfan 3 by the first secondary coil L2 is introduced as a example by connecting the source electrode of NMOS tube Q below: see Fig. 1, the drain electrode of NMOS tube Q is as the outfan of halfwave rectifier, connect filter capacitor C, between port 7 and port 8, export DC voltage.4th outfan 6 of second subprime coil L3 connects input ground GND1; the feedback signal that 3rd outfan 5 of second subprime coil L3 exports as the first secondary coil L2; for regulating and control the stability of output voltage; and through light-coupled isolation protection circuit 9, be used for driving NMOS tube Q to open or close.Seeing Fig. 1, when first outfan 3 of the first secondary coil L2 is output as positive pulse, the 3rd outfan 5 of second subprime coil L3 exports positive pulse, after light-coupled isolation protection circuit 9, exports negative pulse, and now NMOS tube exists VGS<Vth, NMOS tube Q disconnects, and secondary positive pulse signal cannot pass through NMOS tube Q.When first outfan 3 of the first secondary coil L2 is output as negative pulse, the 3rd outfan 5 of second subprime coil L3 is negative pulse, after isolation protective circuit 9, exports positive pulse, and now NMOS tube exists VGS>Vth, NMOS tube Q turns on, and i.e. secondary undersuing is by NMOS tube Q, it is achieved halfwave rectifier, more after filtering after electric capacity C, at port and the DC voltage that needs with port 8 output.
The Flyback circuit that this utility model embodiment provides, at least possesses following beneficial effect:
The Flyback circuit that this utility model embodiment provides, the phase place of the PWM ripple controlling signal and the first secondary coil output of metal-oxide-semiconductor switch is identical so that the Phase synchronization of Flyback circuit and have stable voltage and export.The Flyback circuit that this utility model embodiment provides, the feedback signal utilizing transformator second subprime coil controls the switch of metal-oxide-semiconductor, circuit structure design is ingenious, and the secondary output of transformator only needs two coils, without customizing special transformator, it is not take up more area, reduces production cost.
The Flyback circuit that this utility model embodiment provides, utilizes metal-oxide-semiconductor to carry out rectification, and conversion efficiency is high, it is possible to provide bigger electric current and support bigger power output.
The Flyback circuit that this utility model embodiment provides, metal-oxide-semiconductor can use NMOS tube or PMOS, and the selection range of metal-oxide-semiconductor is wide.
The Flyback circuit that this utility model embodiment provides, protection circuit uses light-coupled isolation protection circuit, and isolation effect is good, can be prevented effectively from the crosstalk between signal.
The Flyback circuit that this utility model embodiment provides, filter unit uses filter capacitor, and the simple in construction of filter capacitor, cost are relatively low, are provided simultaneously with preferable filter effect, on the premise of ensureing Flyback circuit filtering effect, reduces production cost.
This utility model embodiment provide Flyback circuit, can at 125 DEG C, the highest at a temperature of work.
It should be noted last that, above detailed description of the invention is only in order to illustrate the technical solution of the utility model and unrestricted, although this utility model being described in detail with reference to example, it will be understood by those within the art that, the technical solution of the utility model can be modified or equivalent, without deviating from the spirit and scope of technical solutions of the utility model, it all should be contained in the middle of right of the present utility model.
Claims (6)
1. a Flyback circuit, it is characterised in that including: transformator, metal-oxide-semiconductor, protection circuit and filter unit；
The coiler part of described transformator is made up of iron core, primary coil, the first secondary coil and second subprime coil；The two ends of described primary coil are first input end and the second input, and described first input end and described second input are used for inputting PWM ripple signal；
The two ends of described first secondary coil are the first outfan and the second outfan, and described first outfan is connected with the source electrode of described metal-oxide-semiconductor, described second output termination output ground；The drain electrode of described metal-oxide-semiconductor is connected with one end of described filter unit, another termination described output ground of described filter unit；The grid of described metal-oxide-semiconductor is connected with the outfan of described protection circuit, and described protection circuit is connected with described the most respectively with inputting ground and described output；
The two ends of described second subprime coil are the 3rd outfan and the 4th outfan；Described 3rd outfan is connected with the input of described protection circuit, described 4th output termination input ground；
One end of described filter unit is connected with one end of voltage output end mouth, and the other end of described filter unit is connected with the other end of described voltage output end mouth, and described voltage output end mouth is total output interface of described Flyback circuit.
2. Flyback circuit as claimed in claim 1, it is characterised in that described iron core is bar-shaped iron core.
3. Flyback circuit as claimed in claim 2, it is characterised in that described primary coil and described second subprime coil are arranged on the same side of described iron core, and described first secondary coil is arranged on the opposite side of described iron core；
Described second subprime coil is arranged on the lower section of described primary coil.
4. the Flyback circuit as described in any one of claims 1 to 3, it is characterised in that described metal-oxide-semiconductor is NMOS tube or PMOS.
5. the Flyback circuit as described in any one of claims 1 to 3, it is characterised in that described protection circuit is light-coupled isolation protection circuit.
6. the Flyback circuit as described in any one of claims 1 to 3, it is characterised in that described filter unit is filter capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520905725.5U CN205430080U (en) | 2015-11-13 | 2015-11-13 | Flyback circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520905725.5U CN205430080U (en) | 2015-11-13 | 2015-11-13 | Flyback circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205430080U true CN205430080U (en) | 2016-08-03 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520905725.5U Expired - Fee Related CN205430080U (en) | 2015-11-13 | 2015-11-13 | Flyback circuit |
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| Country | Link |
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| CN (1) | CN205430080U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105337517A (en) * | 2015-11-13 | 2016-02-17 | 张艳艳 | Flyback circuit |
-
2015
- 2015-11-13 CN CN201520905725.5U patent/CN205430080U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105337517A (en) * | 2015-11-13 | 2016-02-17 | 张艳艳 | Flyback circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CB03 | Change of inventor or designer information |
Inventor after: Zhang Yanyan Inventor after: Cai Mingze Inventor before: Zhang Yanyan Inventor before: Chen Xiaocai |
|
| CB03 | Change of inventor or designer information | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20170809 Address after: 201620 Shanghai city Songjiang District Guangfulin road 1518 Lane 587, room 801 Co-patentee after: Cai Mingze Patentee after: Zhang Yanyan Address before: 201620 Shanghai city Songjiang District Fulin road 1518 Lane No. 587 room 801 Co-patentee before: Chen Xiaocai Patentee before: Zhang Yanyan |
|
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20160803 Termination date: 20201113 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |