CN209963956U - Flyback switching power supply - Google Patents
Flyback switching power supply Download PDFInfo
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- CN209963956U CN209963956U CN201920544722.1U CN201920544722U CN209963956U CN 209963956 U CN209963956 U CN 209963956U CN 201920544722 U CN201920544722 U CN 201920544722U CN 209963956 U CN209963956 U CN 209963956U
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- inductor
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- resistor
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- power supply
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Abstract
The utility model belongs to the technical field of the switching power supply technique and specifically relates to a flyback switching power supply, including rectifier filter circuit, a transformer, output filter circuit and voltage feedback circuit, the transformer includes elementary inductance and secondary inductance, the one end of elementary inductance is got the electricity from rectifier filter circuit's output, the other termination of elementary inductance has the built-in control chip who has switch tube and self-power module, the input and the other end of elementary inductance of switch tube are connected, be equipped with leakage inductance absorption circuit between the elementary inductance both ends, the one end and the output filter circuit of secondary inductance are connected, voltage feedback circuit includes the opto-coupler, voltage acquisition branch road and static operating point branch road are all got the electricity from output filter circuit's output. The utility model discloses an optimize voltage feedback circuit and improve power output stability to further reduce the whole volume of power, reduce the power distribution and the wiring degree of difficulty.
Description
Technical Field
The utility model belongs to the technical field of switching power supply technique and specifically relates to a flyback switching power supply.
Background
Switching power supply wide application is in modern society, flyback switching power supply because of its have simple structure and components and parts advantage few, especially be fit for using in the occasion that the miniwatt just has the restriction to the space size, especially in application fields such as some security protections and thing networking, the product in this type of field is designed the size less and needs work for a long time usually, the core component is comparatively sensitive, current flyback switching power supply work efficiency is on the low side, output current pulsation is great, influence the work of equipment core component, moreover, from the perspective of manufacturing cost, current flyback switching power supply's structure still can be simplified, the size still can further reduce.
SUMMERY OF THE UTILITY MODEL
The utility model aims at overcoming current flyback switching power supply structure and being difficult to further simplify and the undulant great defect of output current.
In order to achieve the purpose, the utility model discloses a flyback switching power supply, including rectifier filter circuit, a transformer, output filter circuit and voltage feedback circuit, the transformer includes primary inductance and secondary inductance, the one end of primary inductance is got from rectifier filter circuit's output, the other termination of primary inductance has built-in switch tube and self-power module's control chip, the input of switch tube is connected with the other end of primary inductance, be equipped with leakage inductance absorption circuit between the primary inductance both ends, the one end of secondary inductance is connected with output filter circuit, the power pin of control chip is through the first electric capacity and the second electric capacity ground connection that each other is parallelly connected; the voltage feedback circuit comprises an optical coupler, a voltage acquisition branch and a static working point branch, the voltage acquisition branch and the static working point branch all take power from the output end of the output filter circuit, the voltage acquisition branch comprises a first resistor and a second resistor which are connected in sequence, the static working point branch comprises a third resistor which is connected in sequence, a fourth resistor and a voltage stabilizing chip, the cathode of the voltage stabilizing chip is connected with the fourth resistor, a luminous body of the optical coupler is bridged at the side of the fourth resistor, one end of the luminous body of the optical coupler is connected with the voltage feedback end of the control chip, a third capacitor is bridged between the static working point branch and the first resistor, and the input end of the voltage stabilizing chip is connected between the first resistor and the second resistor.
Preferably, the rectification filter circuit comprises a common-mode inductor and a bridge rectifier which are connected in sequence, the front side and the rear side of the common-mode inductor are respectively connected with a fourth capacitor and a fifth capacitor in a cross mode, and a thermistor for suppressing surge current is arranged on one of connection paths of the common-mode inductor and the bridge rectifier.
Preferably, the output filter circuit comprises a rectifier diode, a sixth capacitor, a seventh capacitor and a differential mode output inductor, a cathode of the rectifier diode is connected with one end of a secondary inductor of the transformer, the differential mode output inductor is arranged behind a power taking point of the voltage feedback circuit, an anode of the rectifier diode is connected with an input end of the differential mode output inductor, and the fifth capacitor and the sixth capacitor are connected to an anode of the rectifier diode and an output end of the differential mode output inductor in a bypass mode.
Furthermore, the output end of the secondary inductor is divided into two parts, and the type of the rectifier diode is PDS 560-13.
Preferably, the leakage inductance absorption circuit includes a clamping diode, a fifth resistor and an eighth capacitor, the fifth resistor and the eighth capacitor are respectively connected to a connection path between the primary inductor and the rectifying and filtering circuit in a bypass manner, a cathode of the clamping diode is connected to the other end of the fifth resistor and the other end of the eighth capacitor, and an anode of the clamping diode is connected to the other end of the primary inductor.
Preferably, the signal of the control chip is an NCP1115AP100G chip.
Preferably, the model of the voltage stabilizing chip is TLV431A type chip.
The utility model has the advantages that: the power supply has a simple circuit structure, the output stability of the power supply is improved by optimizing a voltage feedback circuit, and meanwhile, the whole volume of the power supply is further reduced and the power supply layout and wiring difficulty is reduced by adopting a control chip with a built-in switching tube and a self-powered module.
Drawings
FIG. 1: the principle schematic diagram of the flyback switching power supply.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the present invention will be further described with reference to the following embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Fig. 1 is a schematic structural diagram of a flyback switching power supply in this embodiment. As shown in fig. 1, the flyback switching power supply includes a rectifying filter circuit 10, a transformer 20, an output filter circuit 30, and a voltage feedback circuit 40.
The transformer 20 includes a primary inductor L2 and a secondary inductor L3, one end of the primary inductor L2 gets power from the output end of the rectifying and filtering circuit 10, the other end of the primary inductor L2 is connected to a control chip U1 with a switch tube and a self-powered module built in, the input end of the switch tube is connected to the other end of the primary inductor L2, a leakage inductance absorption circuit 50 is arranged between the two ends of the primary inductor L2, one end of the secondary inductor L3 is connected to the output filtering circuit 30, in this embodiment, the turn ratio of the primary inductor L2 to the secondary inductor L3 is 100:5, a power supply pin VCC of the control chip U1 is grounded through a first capacitor C4 and a second capacitor C5 which are connected in parallel, the model of the control chip U1 is NCP1115AP100G, the first capacitor C4 is an energy storage capacitor, the second capacitor C5 is a filter capacitor, the self-powered module supplies working electric energy to the control chip U1, and the control chip U1 does not need to be powered from the outside, so that elements such as a current-limiting resistor and a starting resistor are omitted, and a circuit is simplified.
The voltage feedback circuit 40 comprises an optical coupler U2, a voltage acquisition branch 41 and a static operating point branch 42, the voltage acquisition branch 41 and the static operating point branch 42 all take power from the output end of the output filter circuit 30, the voltage acquisition branch 41 comprises a first resistor R4 and a second resistor R6 which are sequentially connected, the static operating point branch 42 comprises a third resistor R2, a fourth resistor R3 and a voltage stabilizing chip U3 which are sequentially connected, the model of the voltage stabilizing chip U3 is a TLV431A type chip, the cathode of the voltage stabilizing chip U3 is connected with the fourth resistor R3, the luminous body of the optical coupler U3 is bridged at the side of the fourth resistor R3, one end of the luminous body of the optical coupler U3 is connected with the voltage feedback end FB of the control chip U1, a third capacitor C10 is bridged between the static operating point branch 42 and the first resistor R4, and the input end of the voltage stabilizing chip U3 is connected between the first resistor R4 and the second resistor R6.
The voltage feedback means of prior art realization is that opto-coupler U3 gathers voltage signal from the output, and opto-coupler U3 photoreceptor one end is connected with secondary winding, and the other end is connected with chip voltage feedback end, and this kind of feedback structure has higher feedback precision, but feedback information receives secondary winding's impurity signal interference easily, influences feedback precision. The voltage feedback circuit 40 information source is at the direct current output end of output filter circuit 30, and the photic body one end of opto-coupler U2 is connected with the voltage feedback end FB of control chip U1, and the other end is directly ground connection, can feed back output voltage signal to control chip U1 more directly perceivedly, reduces the operation load of control chip U1, improves the holistic output signal of power and adjusts efficiency.
In this embodiment, the rectifying and filtering circuit 10 further includes a common-mode inductor L1 and a bridge rectifier BD1 that are connected in sequence, a fourth capacitor C1 and a fifth capacitor C2 are respectively connected across the front side and the rear side of the common-mode inductor L1, where the common-mode inductor L1 is used to remove common-mode interference, the fourth capacitor C1 and the fifth capacitor C2 are both X capacitors and are used to remove differential-mode interference, and a thermistor RV2 for suppressing surge current is disposed on one of connection paths of the common-mode inductor L1 and the bridge rectifier BD 1.
Specifically, the output filter circuit 30 includes a rectifier diode D2, a sixth capacitor C8, a seventh capacitor C9, and a differential mode output inductor L4, a cathode of the rectifier diode D2 is connected to one end of the secondary inductor L3, a differential mode output inductor L4 is disposed behind a power-taking point of the voltage feedback circuit 40, an anode of the rectifier diode D2 is connected to an input terminal of the differential mode output inductor L4, and the fifth capacitor C2 and the sixth capacitor C8 are connected to an anode of the rectifier diode D2 and an output terminal of the differential mode output inductor L4. To further reduce the leakage inductance of the secondary inductor L3, the output of the secondary inductor L3 is divided into two sets of line outputs and a diode of the PDS560-13 type with two sets of inputs is used as the rectifier diode D2.
Specifically, the leakage inductance absorption circuit 50 includes a clamping diode D1, a fifth resistor R1, and an eighth capacitor C7, the fifth resistor R1 and the eighth capacitor C7 are respectively connected by the bypass of the primary inductor L2 and the connection path of the rectifier filter circuit 10, the cathode of the clamping diode D1 is connected to the other end of the fifth resistor R1 and the other end of the eighth capacitor C7, and the anode of the clamping diode D1 is connected to the other end of the primary inductor L2.
The flyback switching power supply adopts the control chip U1 with the built-in switching tube, and the self-powered module is arranged in the control chip U1, so that the number of elements of the power supply is reduced, the wiring difficulty of the power supply is reduced, and the circuit structure of the flyback switching power supply is simpler than that of the existing flyback switching power supply; in other aspects, the rectifier diode D2 with higher reverse withstand voltage and forward current parameters is selected, a diode absorption circuit is omitted, and in the embodiment, the model of the rectifier diode D2 is PDS 560-13.
To sum up, the utility model discloses a flyback switching power supply has succinct circuit structure, improves power output stability through optimizing voltage feedback circuit, adopts built-in switch tube and self-power module's control chip simultaneously, further reduces the whole volume of power, reduces the power overall arrangement and the wiring degree of difficulty, has progressive meaning.
Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (7)
1. A flyback switching power supply is characterized in that: the transformer comprises a primary inductor and a secondary inductor, wherein one end of the primary inductor gets electricity from the output end of the rectification filter circuit, the other end of the primary inductor is connected with a control chip internally provided with a switching tube and a self-powered module, the input end of the switching tube is connected with the other end of the primary inductor, a leakage inductance absorption circuit is arranged between the two ends of the primary inductor, one end of the secondary inductor is connected with the output filter circuit, and a power supply pin of the control chip is grounded through a first capacitor and a second capacitor which are mutually connected in parallel; the voltage feedback circuit comprises an optical coupler, a voltage acquisition branch and a static working point branch, the voltage acquisition branch and the static working point branch all take power from the output end of the output filter circuit, the voltage acquisition branch comprises a first resistor and a second resistor which are connected in sequence, the static working point branch comprises a third resistor, a fourth resistor and a voltage stabilizing chip which are connected in sequence, the cathode of the voltage stabilizing chip is connected with the fourth resistor, a luminous body of the optical coupler is bridged at the side of the fourth resistor, one end of the luminous body of the optical coupler is connected with the voltage feedback end of the control chip, a third capacitor is bridged between the static working point branch and the first resistor, and the input end of the voltage stabilizing chip is connected between the first resistor and the second resistor.
2. The flyback switching power supply of claim 1, wherein: the rectification filter circuit comprises a common-mode inductor and a bridge rectifier which are connected in sequence, a fourth capacitor and a fifth capacitor are respectively connected to the front side and the rear side of the common-mode inductor in a cross mode, and a thermistor used for suppressing surge current is arranged on one of connecting passages of the common-mode inductor and the bridge rectifier.
3. The flyback switching power supply of claim 1, wherein: the output filter circuit comprises a rectifier diode, a sixth capacitor, a seventh capacitor and a differential mode output inductor, wherein the cathode of the rectifier diode is connected with one end of a secondary inductor of the transformer, the differential mode output inductor is arranged behind a power taking point of the voltage feedback circuit, the anode of the rectifier diode is connected with the input end of the differential mode output inductor, and the fifth capacitor and the sixth capacitor are respectively connected with the anode of the rectifier diode and the output end of the differential mode output inductor in a bypass mode.
4. The flyback switching power supply of claim 3, wherein: the output end of the secondary inductor is divided into two parts, and the type of the rectifier diode is PDS 560-13.
5. The flyback switching power supply of claim 1, wherein: the leakage inductance absorption circuit comprises a clamping diode, a fifth resistor and an eighth capacitor, the fifth resistor and the eighth capacitor are respectively connected to a connection circuit of the primary inductor and the rectification filter circuit in a bypass mode, the cathode of the clamping diode is connected with the other ends of the fifth resistor and the eighth capacitor, and the anode of the clamping diode is connected with the other end of the primary inductor.
6. The flyback switching power supply of claim 1, wherein: the signal of the control chip is an NCP1115AP100G chip.
7. The flyback switching power supply of claim 1, wherein: the model of the voltage stabilizing chip is a TLV431A type chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920544722.1U CN209963956U (en) | 2019-04-19 | 2019-04-19 | Flyback switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920544722.1U CN209963956U (en) | 2019-04-19 | 2019-04-19 | Flyback switching power supply |
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| Publication Number | Publication Date |
|---|---|
| CN209963956U true CN209963956U (en) | 2020-01-17 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201920544722.1U Expired - Fee Related CN209963956U (en) | 2019-04-19 | 2019-04-19 | Flyback switching power supply |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112383234A (en) * | 2020-10-31 | 2021-02-19 | 青岛鼎信通讯股份有限公司 | Circuit and method for reducing switching power supply ripple for power industry product |
-
2019
- 2019-04-19 CN CN201920544722.1U patent/CN209963956U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112383234A (en) * | 2020-10-31 | 2021-02-19 | 青岛鼎信通讯股份有限公司 | Circuit and method for reducing switching power supply ripple for power industry product |
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| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20200117 Termination date: 20200419 |