CN103051218A - Flyback converter - Google Patents
Flyback converter Download PDFInfo
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- CN103051218A CN103051218A CN 201210568360 CN201210568360A CN103051218A CN 103051218 A CN103051218 A CN 103051218A CN 201210568360 CN201210568360 CN 201210568360 CN 201210568360 A CN201210568360 A CN 201210568360A CN 103051218 A CN103051218 A CN 103051218A
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Abstract
The invention provides a flyback converter which solves the problem that current ripples which flow through a primary power switch under the light load state of an existing flyback converter are large. The flyback converter comprises an input port, an output port, a rectifier unit, a primary power switch, a secondary diode, an output capacitor, a feedback component, a voltage comparator, a secondary connecting resistor, a primary connecting resistor, a Zener diode, a selection switch, a current comparator and a control and driving circuit. According to the flyback converter, the current ripples which flow through the primary power switch in the light load state of the flyback converter can be reduced.
Description
Technical field
The present invention relates to electronic technology field, particularly a kind of anti exciting converter.
Background technology
Anti exciting converter is called again single-ended flyback or buck-boost transducer, and the voltage of the comparable power supply of its output voltage is high or low.Typical case's anti exciting converter as shown in Figure 1, this anti exciting converter comprises: input port receives input voltage vin; Output port provides output voltage V o; Rectification unit Rec is coupled to input port and receives input voltage vin; Transformer comprises former limit winding T1 and secondary winding T2, and described former limit winding T1 is coupled to rectification unit Rec; Former limit power switch S is coupled in former limit winding T1 and former limit with reference between the ground; Secondary diode D is coupled between secondary winding T2 and the output port; Output capacitor Co is coupled in output port and with reference between the ground.Existing anti exciting converter adopts peak-current mode control usually, makes the current peak that flows through former limit power switch S be adjusted to a constant peak.Yet use this control mode, no matter anti exciting converter is in heavy condition or light condition, and the current peak that flows through former limit power switch S all is adjusted to same peak value.So that anti exciting converter flows through the current ripples of former limit power switch S under light condition very large.
Summary of the invention
The present invention proposes a kind of anti exciting converter, has solved existing anti exciting converter large problem of ripple under light condition.
Technical scheme of the present invention is achieved in that
A kind of anti exciting converter comprises: input port receives input voltage; Output port provides output voltage; Rectification unit is coupled to input port and receives input voltage, produces commutating voltage; Transformer comprises former limit winding and secondary winding, and its limit, Central Plains winding and secondary winding respectively have the first terminal and the second terminal, and the first terminal of former limit winding is coupled to rectification unit and receives commutating voltage, and the second terminal of secondary winding connects secondary with reference to ground; Former limit power switch is coupled in the second terminal of former limit winding and former limit with reference between the ground; The secondary diode is coupled between the first terminal and output port of secondary winding; Output capacitor is coupled in output port and secondary with reference between the ground; Feedback component comprises secondary part and former limit part; Secondary contact resistance, Zener diode and former limit contact resistance, secondary part, secondary contact resistance and the Zener diode that wherein feeds back winding is coupled in series in output port and secondary with reference between the ground, to produce feedback voltage in the former limit of feedback component part; Voltage comparator, have in-phase input end, inverting input and lead-out terminal, its in-phase input end receives reference voltage, its inverting input is coupled to former limit with reference to ground via former limit part and the former limit contact resistance of feedback component, to receive feedback voltage, its lead-out terminal produces voltage comparison signal; Selector switch, have the first terminal, the second terminal, the 3rd terminal and control terminal, its the first terminal couples the first current peak, and its second terminal couples the second current peak, and its control terminal is coupled to the lead-out terminal receiver voltage comparison signal of voltage comparator; Current comparator, have in-phase input end, inverting input and lead-out terminal, the coupled in series node that its in-phase input end is coupled to former limit power switch and former limit winding characterizes the current sampling signal that flows through former limit power switch to receive, its inverting input is coupled to the 3rd terminal of selector switch, its lead-out terminal generation current comparison signal; Control and drive circuit are coupled to the lead-out terminal received current comparison signal of current comparator, and based on the electric current comparison signal, produce switching drive signal, to control the break-make of former limit power switch.
Alternatively, described rectification unit comprises the rectifier circuit that is comprised of four diodes.
Alternatively, when voltage comparison signal was high level, the 3rd terminal of selector switch was connected to its first terminal, so that the inverting input of current comparator receives the first current peak; When voltage comparison signal was low level, the 3rd terminal of selector switch was connected to its second terminal, so that the inverting input of current comparator receives the second current peak.
Alternatively, described the first current peak is greater than the second current peak.
Alternatively, described feedback component comprises photoelectrical coupler.
The invention has the beneficial effects as follows: can reduce the current ripples that flow through former limit power switch of anti exciting converter under light condition.
Description of drawings
In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, the below will do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art, apparently, accompanying drawing in the following describes only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is the typical circuit structural representation of existing anti exciting converter;
Fig. 2 is the electrical block diagram of a kind of anti exciting converter 100 of the present invention.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not paying the every other embodiment that obtains under the creative work prerequisite.
As shown in Figure 2, anti exciting converter 100 of the present invention comprises: input port 101 receives input voltage vin; Output port 102 provides output voltage V o; Rectification unit 103 is coupled to input port 101 and receives input voltage vin, produces commutating voltage; Transformer, comprise former limit winding 104-1 and secondary winding 104-2, its limit, Central Plains winding 104-1 and secondary winding 104-2 respectively have the first terminal and the second terminal, the first terminal of former limit winding 104-1 is coupled to rectification unit 103 and receives commutating voltage, and the second terminal of secondary winding 104-2 connects secondary with reference to ground; Former limit power switch 105 is coupled in the second terminal of former limit winding 104-1 and former limit with reference between the ground; Secondary diode 106 is coupled between the first terminal and output port 102 of secondary winding 104-2; Output capacitor 107 is coupled in output port 102 and secondary with reference between the ground; Feedback component comprises secondary part 108-1 and former limit part 108-2; Secondary contact resistance 109, Zener diode 110 and former limit contact resistance 111, wherein the secondary part 108-1 of feedback component, secondary contact resistance 109 and Zener diode 110 are coupled in series in output port 102 and secondary with reference between the ground, produce feedback voltage Vfb with the former limit part 108-1 in feedback component; Voltage comparator 112, have in-phase input end, inverting input and lead-out terminal, its in-phase input end receives reference voltage Vref, its inverting input is coupled to former limit with reference to ground via former limit part 108-2 and the former limit contact resistance 111 of feedback component, to receive feedback voltage Vfb, its lead-out terminal produces voltage comparison signal; Selector switch 113, have the first terminal, the second terminal, the 3rd terminal and control terminal, its the first terminal couples the first current peak Ilim1, and its second terminal couples the second current peak Ilim2, and its control terminal is coupled to the lead-out terminal receiver voltage comparison signal of voltage comparator 112; Current comparator 114, have in-phase input end, inverting input and lead-out terminal, the coupled in series node that its in-phase input end is coupled to former limit power switch 105 and former limit winding 104-1 characterizes the current sampling signal Isen that flows through former limit power switch to receive, its inverting input is coupled to the 3rd terminal of selector switch 113, its lead-out terminal generation current comparison signal; Control and drive circuit 115 are coupled to the lead-out terminal received current comparison signal of current comparator 114, and based on the electric current comparison signal, produce switching drive signal, to control the break-make of former limit power switch 105.
Preferably, described rectification unit 103 comprises the rectifier circuit that is comprised of four diodes.
Preferably, described feedback component comprises photoelectrical coupler.
Preferably, when voltage comparison signal is high level, the 3rd terminal of selector switch 113 is connected to its first terminal, so that the inverting input of current comparator 114 receives the first current peak Ilim1 when voltage comparison signal is low level, the 3rd terminal of selector switch 113 is connected to its second terminal, so that the inverting input of current comparator 114 receives the second current peak Ilim2.
Preferably, the first current peak Ilim1 is greater than the second current peak Ilim2.
When the normal operation of anti exciting converter 100, when former limit power switch 105 is switched on, input voltage vin via the former limit winding 104-1 of rectification unit 103, transformer and former limit power switch 105 to former limit with reference to ground.Former limit winding 104-1 begins stored energy, and the electric current that flows through simultaneously former limit power switch 105 begins to increase.When it increases to signal greater than current comparator 114 inverting inputs, the electric current comparison signal trigging signal of current comparator 114 outputs.Accordingly, the switching drive signal trigging signal of control and drive circuit 115 outputs, so that former limit power switch 105 is disconnected, secondary diode 106 is switched on.The energy that is stored in subsequently former limit winding 104-1 is transmitted and is converted into output voltage V o via secondary winding 104-2, secondary diode 106 and output capacitor 107.
When the load of anti exciting converter 100 is relatively heavier, output voltage V o less, then also less of feedback voltage Vfb.Feedback voltage Vfb is less than reference voltage Vref at this moment, and the voltage comparison signal of voltage comparator 112 outputs is high level.Then the 3rd terminal of selector switch 113 is connected to its first terminal, so that the inverting input of current comparator 114 receives the first current peak Ilim1.Namely under heavy condition, when current sampling signal reaches the first current peak Ilim1, the electric current comparison signal trigging signal of current comparator 114 outputs, and then via behind control and the drive circuit 115 former limit power switch 105 being disconnected.
When the load of anti exciting converter 100 was relatively light, output voltage V o was relatively large, and then feedback voltage Vfb is also relatively large.Feedback voltage Vfb is greater than reference voltage Vref at this moment, and the voltage comparison signal of voltage comparator 112 outputs is low level.Then the 3rd terminal of selector switch 113 is connected to its second terminal, so that the inverting input of current comparator 114 receives the second current peak Ilim2.Namely under light condition, when current sampling signal reaches the second current peak Ilim2, the electric current comparison signal trigging signal of current comparator 114 outputs, and then via behind control and the drive circuit 115 former limit power switch 105 being disconnected.
As previously mentioned, the first current peak Ilim1 is greater than the second current peak Ilim2, so that anti exciting converter 100 flows through the current peak of former limit power switch under light condition, the current peak that namely flows through the transformer primary side winding is less than flowing through the current peak of former limit power switch under its heavy condition, thereby reduced to flow through under its light condition the current ripples of former limit power switch.
The above only is preferred embodiment of the present invention, and is in order to limit the present invention, within the spirit and principles in the present invention not all, any modification of doing, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (5)
1. an anti exciting converter is characterized in that, comprising:
Input port receives input voltage;
Output port provides output voltage;
Rectification unit is coupled to input port and receives input voltage, produces commutating voltage;
Transformer comprises former limit winding and secondary winding, and its limit, Central Plains winding and secondary winding respectively have the first terminal and the second terminal, and the first terminal of former limit winding is coupled to rectification unit and receives commutating voltage, and the second terminal of secondary winding connects secondary with reference to ground;
Former limit power switch is coupled in the second terminal of former limit winding and former limit with reference between the ground;
The secondary diode is coupled between the first terminal and output port of secondary winding;
Output capacitor is coupled in output port and secondary with reference between the ground;
Feedback component comprises secondary part and former limit part;
Secondary contact resistance, Zener diode and former limit contact resistance, wherein the secondary part of feedback component, secondary contact resistance and Zener diode are coupled in series in output port and secondary with reference between the ground, to produce feedback voltage in the former limit of feedback component part;
Voltage comparator, have in-phase input end, inverting input and lead-out terminal, its in-phase input end receives reference voltage, its inverting input is coupled to former limit with reference to ground via former limit part and the former limit contact resistance of feedback component, to receive feedback voltage, its lead-out terminal produces voltage comparison signal;
Selector switch, have the first terminal, the second terminal, the 3rd terminal and control terminal, its the first terminal couples the first current peak, and its second terminal couples the second current peak, and its control terminal is coupled to the lead-out terminal receiver voltage comparison signal of voltage comparator;
Current comparator, have in-phase input end, inverting input and lead-out terminal, the coupled in series node that its in-phase input end is coupled to former limit power switch and former limit winding characterizes the current sampling signal that flows through former limit power switch to receive, its inverting input is coupled to the 3rd terminal of selector switch, its lead-out terminal generation current comparison signal;
Control and drive circuit are coupled to the lead-out terminal received current comparison signal of current comparator, and based on the electric current comparison signal, produce switching drive signal, to control the break-make of former limit power switch.
2. anti exciting converter as claimed in claim 1 is characterized in that, described rectification unit comprises the rectifier circuit that is comprised of four diodes.
3. anti exciting converter as claimed in claim 1 is characterized in that, wherein
When voltage comparison signal was high level, the 3rd terminal of selector switch was connected to its first terminal, so that the inverting input of current comparator receives the first current peak;
When voltage comparison signal was low level, the 3rd terminal of selector switch was connected to its second terminal, so that the inverting input of current comparator receives the second current peak.
4. anti exciting converter as claimed in claim 1 is characterized in that, described the first current peak is greater than the second current peak.
5. anti exciting converter as claimed in claim 1 is characterized in that, described feedback component comprises photoelectrical coupler.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201210568360 CN103051218A (en) | 2012-12-12 | 2012-12-12 | Flyback converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201210568360 CN103051218A (en) | 2012-12-12 | 2012-12-12 | Flyback converter |
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| Publication Number | Publication Date |
|---|---|
| CN103051218A true CN103051218A (en) | 2013-04-17 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201210568360 Pending CN103051218A (en) | 2012-12-12 | 2012-12-12 | Flyback converter |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105472520A (en) * | 2015-12-25 | 2016-04-06 | 青岛北斗星云通信科技有限公司 | Electronic hearing aid device |
| CN105472521A (en) * | 2015-12-25 | 2016-04-06 | 青岛北斗星云通信科技有限公司 | Ear barrier electronic auxiliary device |
| CN105471066A (en) * | 2015-12-25 | 2016-04-06 | 青岛海特新蓝生物科技有限公司 | Power generation base station |
| CN105491498A (en) * | 2015-12-28 | 2016-04-13 | 青岛玻莱莫斯新材料技术有限公司 | Hearing assistance instrument |
| CN105490340A (en) * | 2015-12-25 | 2016-04-13 | 青岛朝阳华泰管理咨询服务有限公司 | Power generation base station |
| CN105491499A (en) * | 2015-12-28 | 2016-04-13 | 青岛玻莱莫斯新材料技术有限公司 | Elderly hearing aid |
| CN105635923A (en) * | 2015-12-25 | 2016-06-01 | 青岛北斗星云通信科技有限公司 | Electronic hearing aid |
| CN105628165A (en) * | 2015-12-20 | 2016-06-01 | 青岛海特新蓝生物科技有限公司 | Measuring scale |
-
2012
- 2012-12-12 CN CN 201210568360 patent/CN103051218A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105628165A (en) * | 2015-12-20 | 2016-06-01 | 青岛海特新蓝生物科技有限公司 | Measuring scale |
| CN105472520A (en) * | 2015-12-25 | 2016-04-06 | 青岛北斗星云通信科技有限公司 | Electronic hearing aid device |
| CN105472521A (en) * | 2015-12-25 | 2016-04-06 | 青岛北斗星云通信科技有限公司 | Ear barrier electronic auxiliary device |
| CN105471066A (en) * | 2015-12-25 | 2016-04-06 | 青岛海特新蓝生物科技有限公司 | Power generation base station |
| CN105490340A (en) * | 2015-12-25 | 2016-04-13 | 青岛朝阳华泰管理咨询服务有限公司 | Power generation base station |
| CN105635923A (en) * | 2015-12-25 | 2016-06-01 | 青岛北斗星云通信科技有限公司 | Electronic hearing aid |
| CN105491498A (en) * | 2015-12-28 | 2016-04-13 | 青岛玻莱莫斯新材料技术有限公司 | Hearing assistance instrument |
| CN105491499A (en) * | 2015-12-28 | 2016-04-13 | 青岛玻莱莫斯新材料技术有限公司 | Elderly hearing aid |
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| Date | Code | Title | Description |
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| C06 | Publication | ||
| PB01 | Publication | ||
| DD01 | Delivery of document by public notice |
Addressee: Lianmeng Electronic Instrument Co., Ltd. Document name: Notification that Application Deemed to be Withdrawn |
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| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20130417 |