CN204408206U - A kind of self-powered circuit of Switching Power Supply - Google Patents

A kind of self-powered circuit of Switching Power Supply Download PDF

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Publication number
CN204408206U
CN204408206U CN201520094974.0U CN201520094974U CN204408206U CN 204408206 U CN204408206 U CN 204408206U CN 201520094974 U CN201520094974 U CN 201520094974U CN 204408206 U CN204408206 U CN 204408206U
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Prior art keywords
voltage
circuit
power supply
switching power
stabilizing
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CN201520094974.0U
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李绍兵
蓝东升
王宗意
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Mornsun Guangzhou Science and Technology Ltd
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Mornsun Guangzhou Science and Technology Ltd
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Abstract

The utility model discloses a kind of self-powered circuit of Switching Power Supply, comprise high frequency transformer 1, boost rectifying circuit 2, linear voltage-stabilizing circuit 3.Described high frequency transformer 1 exports one and the synchronous high-frequency pulse voltage of Switching Power Supply, described boost rectifying circuit 2 receives high-frequency pulse voltage, after boosting rectifying and wave-filtering, form higher direct voltage Vcc, described linear voltage-stabilizing circuit outputs to control chip after this High Level DC Voltage is carried out reduction and voltage stabilizing.The Vcc that the utility model provides is stable, accurate, does not change, do not change with the adjustment of output voltage with the change of output load current.Can be applied in AC-DC, DC-DC Switching Power Supply of band output voltage regulatory function.

Description

A kind of self-powered circuit of Switching Power Supply
Technical field
The utility model relates to a kind of switching power circuit, particularly a kind of self-powered circuit of Switching Power Supply.
Background technology
In Switching Power Supply product, former limit control chip or relevant protective circuit chip need a stable supply power voltage continued, and this voltage is generally at about 12V.In the many application of Switching Power Supply, the input voltage of Switching Power Supply is general all far above this voltage, if Gather and input voltage does this supply power voltage can cause very large step-down loss.Fig. 1 is the most general a kind of supply power mode of currently available technology, start-up circuit Gather and input voltage is that Switching Power Supply does startup use, just start-up circuit is disconnected after Switching Power Supply normally works, by self-powered circuit continued power, self-powered circuit increases an auxiliary winding on main power transformer, the pulse voltage waveform that auxiliary winding produces, by the formation direct current Vcc voltage after rectifying and wave-filtering, uses for control chip.
Following defect is there is in prior art;
1, Switching Power Supply output loading is under heavy duty and no-load condition, because the problem of cross regulation rate, cause Vcc voltage fluctuation amplitude large, it is no problem to be applied in the control chip of the Vcc voltage with wide region or driving chip, but when being applied in the narrow control chip of Vcc voltage range and driving chip, the situation of overvoltage/under-voltage can be caused.
2, in modular power source, output voltage generally has regulatory function, 10% output voltage can be raised and lower 10% output voltage, this Vcc voltage is because coupling output voltage, so when output voltage is raised or turns down, cause self-powered voltage vcc also follow the change of output voltage and change, cause Vcc overvoltage or under-voltage too.
3, the Vcc voltage that above two kinds of situations cause reduces, capital causes self-powered power all to be provided by start-up circuit, the power consumption of start-up circuit is caused to strengthen, the efficiency of power module reduces, and in order to not damage by this large power consumption, the device in start-up circuit, particularly Voltage Cortrol triode need to select larger volume, so just cause power module cost, volume to increase, power density is lowered.
Utility model content
The purpose of this utility model is, provides a kind of self-powered circuit of Switching Power Supply, and described confession circuit possesses Vcc voltage stabilization, does not change with the change of output load current.Need at output voltage, in the modular power source application regulated, not change with the change of output voltage.Transformation can be reduced and assist winding in Switching Power Supply design, the power consumption of start-up circuit can be reduced, reduce the volume of start-up circuit, reach the effect realizing modular power source high power density.Particularly in the application that the VCC voltage range of control chip or driving chip is narrow, there is good effect.The utility model is the Vcc self-powered circuit to prior art, and the general character point in mode of operation carries out innovation improvement, overcomes the shortcoming of self-powered spread of voltage in prior art.
The self-powered circuit of a kind of Switching Power Supply described in the utility model is achieved through the following technical solutions: comprise high frequency transformer, boost rectifying circuit, linear voltage-stabilizing circuit.The pulse voltage of the auxiliary winding coupled transformer primary side winding of high frequency transformer, output to the input of boost rectifying circuit, after this pulse voltage is boosted by boost rectifying circuit, form the input of higher direct voltage output to linear voltage-stabilizing circuit, direct voltage by forming stable Vcc voltage after reduction, voltage stabilizing, is supplied to control chip and the use of other chips by linear voltage-stabilizing circuit.
Preferably, high frequency transformer comprises transformer primary side winding, vice-side winding, auxiliary winding, the former limit winding of transformer and master power switch series connection, and vice-side winding and the series connection of secondary rectifier switch, auxiliary winding is connected with the utility model circuit.
Preferably, boost rectifying circuit comprises the first boost capacitor, the first diode, the second diode, the first filter capacitor.One end of first boost capacitor is connected with one end of the auxiliary winding of transformer, the other end of the first boost capacitor is connected with the anode of the first diode and the second diode cathode respectively, the negative electrode of the first diode is connected with one end of the first filter capacitor, for the output of boost rectifying circuit, the other end of the anode of the second diode, the other end of the first filter capacitor and auxiliary winding N1 is connected to the reference ground of circuit.
Preferably, linear voltage-stabilizing circuit comprises the first divider resistance, the first current-limiting resistance, the first voltage stabilizing didoe, the first Voltage Cortrol triode.One end of first divider resistance is connected to the output of boost rectifying circuit, the other end of the first divider resistance is connected to the collector electrode of the first Voltage Cortrol triode and one end of the first current-limiting resistance, and the other end of the first current-limiting resistance is connected to the base stage of the first Voltage Cortrol triode and the negative electrode of the first voltage stabilizing didoe.The anode of the first voltage stabilizing didoe is connected to the reference ground of circuit.The emitter of the first Voltage Cortrol triode is connected to Vcc end, powers to IC.
The principle that the utility model realizes stable Vcc voltage is as follows;
Adopt the prior art Switching Power Supply of powering at unloaded or output voltage by lower timing, Vcc self-powered voltage can be caused to reduce, when the voltage that self-powered Vcc voltage provides lower than start-up circuit, the supply current that control chip and other chip need all is provided by start-up circuit, the loss that start-up circuit produces is P=(Vin-Vcc) × Icc, and generally Vin voltage is far above Vcc voltage.So just cause on start-up circuit and create very large dividing potential drop loss, particularly in the Switching Power Supply application of superelevation input voltage.Even if therefore need one when output voltage is turned down, the Vcc that self-powered provides also is higher than start-up circuit output voltage.And Switching Power Supply enter fully loaded work or output voltage when being raised, this voltage can not be raised too much, because Vcc voltage raises easily cause control chip excessive pressure damages.So the solution thought of the utility model technology is, first improve the direct voltage after winding rectifying and wave-filtering by boost rectifying circuit, then by step-down-linear voltage-stabilizing circuit by Vcc voltage stabilization on desirable voltage.
The utility model circuit as shown in Figure 2, comprises high frequency transformer 1, boost rectifying circuit 2, linear voltage-stabilizing circuit 3, after the start-up circuit of Switching Power Supply normally starts, enters normal mode of operation.
The former limit winding of high frequency transformer 1 is connected with a switch, switch continuous firing in work is in conducting and cut-off state, former limit winding Ns creates one have and just have negative pulse voltage, auxiliary winding N1 is coupled former limit winding, also produce one and have the voltage just having negative pulse, this voltage outputs to boost rectifying circuit.
The operation principle of boost rectifying circuit for: when the pulse voltage that boost rectifying circuit receives is negative sense, negative voltage gives the first boost capacitor C1 charging by the second diode D2 of boost rectifying circuit 2, form the positive right negative voltage in a left side at its two ends, amplitude approximates negative voltage.When the pulse voltage of auxiliary winding N1 is switched to forward voltage time, by forming direct voltage after the first boost capacitor C1 and the first diode D1 rectification, the first filter capacitor C2 filtering, because the voltage on the first boost capacitor C1 is without Releasing loop, left positive right negative voltage will keep, so the direct impulse voltage that the direct voltage on filter capacitor C2 equals auxiliary winding N1 adds the voltage on the first boost capacitor C1, so the direct voltage after rectifying and wave-filtering is the direct impulse voltage that auxiliary winding N1 exports add negative-going pulse voltage.
The operation principle of linear voltage-stabilizing circuit 3 is: upborne direct voltage, by the first divider resistance R1, is added in the series loop of the first current-limiting resistance R2 and the first voltage stabilizing didoe ZD1.Coating-forming voltage on the first voltage stabilizing didoe ZD1, the electric current of the first voltage stabilizing didoe ZD1 is flow through in the first current-limiting resistance R2 restriction, ensures voltage-stabiliser tube voltage stabilization and prevents the first voltage stabilizing didoe ZD1 by circuit damage.Stable voltage is supplied to the base stage of the first Voltage Cortrol triode Q1, and the output of linear voltage-stabilizing circuit 3 is also stablized base voltage institute clamper with regard to the voltage of the first Voltage Cortrol triode, forms the stable Vcc voltage exported.
The power consumption that first adjustment triode is formed is Pq1=(V1max-VR1-Vcc) × Icc, V1max is the voltage that boost rectifying circuit exports, VR1 is the voltage on the first divider resistance, because can accomplish that upborne V1max voltage is far below input voltage vin from design, so the loss of adjustment triode will much smaller than the working loss starting triode.
When output voltage is raised, when output loading is heavier again, the direct voltage that boost rectifying circuit exports is raised, and at this moment the first divider resistance R1 can share the power consumption of the first Voltage Cortrol triode Q1.
The principle that described the utility model realizes Vcc self-powered voltage stabilization is, the direct voltage after auxiliary winding rectification post filtering is raised by boost rectifying circuit, Vcc output voltage is stablized again, so more stable self-powered voltage can realized by linear voltage-stabilizing circuit.
Compared with prior art, the utility model has following outstanding advantage:
1, Vcc self-powered voltage does not change with the change of load;
2, Vcc self-powered voltage does not regulate with output voltage and changes;
3, output voltage can be improved and lower the efficiency in applying;
4, the volume of start-up circuit device can be reduced, increase the power density of Switching Power Supply.
Accompanying drawing explanation
Fig. 1 is the self-powered circuit schematic diagram of prior art;
Fig. 2 is the circuit diagram of the utility model embodiment one;
Fig. 3 is the circuit diagram of the utility model in Switching Power Supply application;
Embodiment
Embodiment one
Fig. 2 is circuit diagram of the present utility model, and it comprises high frequency transformer 1, boost rectifying circuit 2, linear voltage-stabilizing circuit 3.
The high-frequency pulse voltage that described high frequency transformer exports and Switching Power Supply is synchronous, the high-frequency pulse voltage of reception is formed higher direct voltage Vcc by described boost rectifying circuit 2 after boosting rectifying and wave-filtering, and the direct voltage after this rising reduces and outputs to control chip after voltage stabilizing by described electric current of voltage regulation.The Vcc that the utility model provides is stable, accurate, does not change, do not change with the change of output voltage with the change of output load current.Can be applied in AC-DC, DC-DC Switching Power Supply of band output voltage regulatory function.
Described high frequency transformer comprises transformer primary side winding Np, vice-side winding Ns, auxiliary winding N1.The former limit winding Np of high frequency transformer and master power switch series connection, vice-side winding Ns and the series connection of secondary rectifier switch, auxiliary winding N1 is connected with the utility model circuit.
Described boost rectifying circuit comprises the firstth boost capacitor C1, first diode D1, second diode D2, first filter capacitor C2, one end of first boost capacitor C1 is connected with one end of the auxiliary winding N1 of transformer, the other end of the first boost capacitor C1 is connected with the anode of the first diode D1 and the second diode D2 negative electrode, the negative electrode of the first diode D1 is connected with one end of the first filter capacitor C2, for the output of boost rectifying circuit, the anode of the second diode D2, the other end of the first filter capacitor C2 and the other end of auxiliary winding N1 are connected to the reference ground of circuit.
Described linear voltage-stabilizing circuit comprises the first divider resistance R1, the first current-limiting resistance R2, the first voltage stabilizing didoe ZD1, the first Voltage Cortrol triode Q1.One end of first divider resistance R1 is connected to the output of boost rectifying circuit, the other end of the first divider resistance R1 is connected to the collector electrode of the first Voltage Cortrol triode Q1 and one end of the first current-limiting resistance R2, and the other end of the first current-limiting resistance R2 is connected to the base stage of the first Voltage Cortrol triode Q1 and the negative electrode of the first voltage stabilizing didoe ZD1.The anode of the first voltage stabilizing didoe ZD1 is connected to the reference ground of circuit.The emitter of the first Voltage Cortrol triode Q1 is connected to IC and powers and export VCC end.
Its operation principle is described in detail in utility model content, does not repeat them here.
Above embodiment just understands method of the present utility model and core concept for helping; for those skilled in the art; under the prerequisite not departing from the utility model principle; by above describe with illustrate can naturally associate other be equal to application scheme; and some improvement that the utility model carried out and modification, all fall into the protection range of claims of the present utility model.

Claims (3)

1. a self-powered circuit for Switching Power Supply, is characterized in that: comprise high frequency transformer, boost rectifying circuit, linear voltage-stabilizing circuit; The auxiliary winding of described high frequency transformer provides a high-frequency pulse voltage to described boost rectifying circuit, after high-frequency pulse voltage described in described boost rectifying circuit receives, carry out boosting and rectification, export a direct voltage to described linear voltage-stabilizing circuit, described linear voltage-stabilizing circuit carries out step-down and voltage stabilizing process to described direct voltage, export one not by the stable Vcc voltage that output loading and switch power source output voltage up-down adjustment affect, be supplied to control chip and use.
2. the self-powered circuit of a kind of Switching Power Supply according to claim 1, is characterized in that: described boost rectifying circuit comprises the first boost capacitor, the first diode, the second diode, the first filter capacitor; One end of the first described boost capacitor is connected with one end of the auxiliary winding of described high frequency transformer, the other end of the first described boost capacitor is connected with the anode of the first described diode and the second described diode cathode respectively, the negative electrode of the first described diode is connected with one end of the first described filter capacitor, for the output of boost rectifying circuit, the other end of the anode of the second described diode, the other end of the first described filter capacitor and the auxiliary winding of described high frequency transformer is connected to the reference ground of circuit.
3. the self-powered circuit of a kind of Switching Power Supply according to claim 1, is characterized in that: described linear voltage-stabilizing circuit comprises the first divider resistance, the first current-limiting resistance, the first voltage stabilizing didoe, the first Voltage Cortrol triode; One end of the first described divider resistance is connected to the output of described boost rectifying circuit, the other end of the first described divider resistance is connected to the collector electrode of the first described Voltage Cortrol triode and one end of the first described current-limiting resistance, and the other end of the first described current-limiting resistance is connected to the base stage of the first described Voltage Cortrol triode and the negative electrode of the first described voltage stabilizing didoe; The anode of the first described voltage stabilizing didoe is connected to the reference ground of circuit; The emitter of the first described Voltage Cortrol triode is connected to Vcc end, powers to IC.
CN201520094974.0U 2015-02-10 2015-02-10 A kind of self-powered circuit of Switching Power Supply Active CN204408206U (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105932890A (en) * 2016-07-06 2016-09-07 电子科技大学 Self-powered circuit applied to switching circuit
WO2018188132A1 (en) * 2017-04-11 2018-10-18 深圳市华星光电技术有限公司 Transformer circuit and method for decreasing no-load power consumption
CN108695995A (en) * 2018-06-15 2018-10-23 哈尔滨工业大学深圳研究生院 A kind of high efficiency resonance type radio energy transmission system
CN109039028A (en) * 2018-07-09 2018-12-18 华为技术有限公司 Control circuit and power supply adaptor applied to power supply adaptor
CN109995252A (en) * 2019-04-22 2019-07-09 合肥惠科金扬科技有限公司 A kind of voltage regulator circuit and switching power circuit

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105932890A (en) * 2016-07-06 2016-09-07 电子科技大学 Self-powered circuit applied to switching circuit
CN105932890B (en) * 2016-07-06 2018-06-19 电子科技大学 A kind of self-powered circuit for switching circuit
WO2018188132A1 (en) * 2017-04-11 2018-10-18 深圳市华星光电技术有限公司 Transformer circuit and method for decreasing no-load power consumption
CN108695995A (en) * 2018-06-15 2018-10-23 哈尔滨工业大学深圳研究生院 A kind of high efficiency resonance type radio energy transmission system
CN108695995B (en) * 2018-06-15 2021-09-10 哈尔滨工业大学深圳研究生院 High-efficiency resonant wireless power transmission system
CN109039028A (en) * 2018-07-09 2018-12-18 华为技术有限公司 Control circuit and power supply adaptor applied to power supply adaptor
CN111884513A (en) * 2018-07-09 2020-11-03 华为技术有限公司 Control circuit applied to power adapter and power adapter
CN111884513B (en) * 2018-07-09 2021-12-03 华为数字能源技术有限公司 Control circuit applied to power adapter and power adapter
CN109995252A (en) * 2019-04-22 2019-07-09 合肥惠科金扬科技有限公司 A kind of voltage regulator circuit and switching power circuit

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