CN103856060A - Flyback switching power supply with adjustable maximum output current - Google Patents
Flyback switching power supply with adjustable maximum output current Download PDFInfo
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- CN103856060A CN103856060A CN201410049002.XA CN201410049002A CN103856060A CN 103856060 A CN103856060 A CN 103856060A CN 201410049002 A CN201410049002 A CN 201410049002A CN 103856060 A CN103856060 A CN 103856060A
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Abstract
The invention discloses a flyback switching power supply with the adjustable maximum output current. The flyback switching power supply comprises a switching power supply input end, a switching power supply output end, a switching power supply main circuit, a voltage sampling circuit, an integrated control circuit and a current sampling circuit. An integrated op-amp circuit is connected between the current sampling circuit and the integrated control circuit. According to the flyback switching power supply with the adjustable maximum output current, the current sampling circuit transmits sampling signals to the current sampling end of the integrated control circuit after the sampling signals are amplified by the integrated op-amp circuit. Due to the fact that the magnification times of the integrated op-amp circuit are adjustable within the larger range, the maximum output current allowed by the switching power supply is better adjusted, the output current can be adjusted to be the upper limit when the output voltage of the switching power supply is stable, and universality of the single-ended flyback switching power supply is improved to a certain extent.
Description
Technical field
The present invention relates to a kind of inverse-excitation type switch power-supply, particularly the adjustable inverse-excitation type switch power-supply of a kind of maximum output current.
Background technology
Single-end flyback switching power supply, because it is simple in structure, needs the element of use few, and cost is low, and volume is little, can realize easily isolation and be easy to realize the many merits such as multichannel output, under the occasion below 200 watts, is widely used, and market is huge; Single-ended flyback power supply constant voltage output at present, the sampling of electric current obtains from the resistance of connecting with power switch pipe, because current sampling resistor resistance is fixed and can not be too little, generally be 1 ohm of left and right, less and the deficiency that can not set of this maximum output current that has just caused power supply to allow, has reduced the versatility of single-end flyback switching power supply product to a certain extent.
Summary of the invention
For the technical problem of above-mentioned existence, the object of the invention is: proposed the adjustable inverse-excitation type switch power-supply of a kind of maximum output current.
Technical solution of the present invention is achieved in that the inverse-excitation type switch power-supply that a kind of maximum output current is adjustable, comprises Switching Power Supply input, Switching Power Supply output, Switching Power Supply main circuit, voltage sample circuit, integral control circuit and current sampling circuit; Described Switching Power Supply input and Switching Power Supply output are arranged on Switching Power Supply main circuit; Described voltage sample circuit and current sampling circuit are electrically connected with integral control circuit respectively, are provided with current sense resistor in current sampling circuit; Described integral control circuit is electrically connected with Switching Power Supply main circuit; Between described current sampling circuit and integral control circuit, be connected with integrated operational amplifier circuit.
Preferably, in described current sampling circuit, current sense resistor is selected the resistance of resistance size between 0.2 milliohm to 6 milliohm.
Preferably, by integrated operational amplifier, the first integrated transporting discharging resistance, the second integrated transporting discharging resistance, integrated transporting discharging, input resistance and integrated transporting discharging regulating resistance form described integrated operational amplifier circuit in the same way; Described the first integrated transporting discharging resistance one end is connected on the reverse input end of integrated operational amplifier, other end ground connection; After described the second integrated transporting discharging resistance and the series connection of integrated transporting discharging regulating resistance, be connected across on the reverse input end and output of integrated operational amplifier; Described integrated transporting discharging in the same way input resistance is connected to the input in the same way of integrated operational amplifier.
Preferably, one end ground connection of described current sense resistor, the other end by integrated transporting discharging in the same way input resistance be connected to the input in the same way of integrated operational amplifier.
Due to the utilization of technique scheme, the present invention compared with prior art has following advantages:
The inverse-excitation type switch power-supply that maximum output current of the present invention is adjustable, the resistance of current sense resistor is milliohm level, and after sampled signal is amplified by integrated operational amplifier circuit, delivers to the current sampling end of integral control circuit again; Because the multiplication factor of integrated operational amplifier circuit is adjustable within a large range, therefore, can realize preferably the adjustability of the maximum output current that Switching Power Supply is allowed, when the output voltage stabilization of Switching Power Supply, output current is adjustable to the upper limit, simultaneously integrated manipulator also can normal response, has improved to a certain extent the versatility of single-end flyback switching power supply product.
Brief description of the drawings
Below in conjunction with accompanying drawing, technical solution of the present invention is described further:
Accompanying drawing 1 is the block diagram of the adjustable inverse-excitation type switch power-supply of a kind of maximum output current of the present invention;
Accompanying drawing 2 is the circuit diagram of the adjustable inverse-excitation type switch power-supply of a kind of maximum output current of the present invention.
Embodiment
Below in conjunction with accompanying drawing, the present invention is described.
As shown in Figure 1-2, the adjustable inverse-excitation type switch power-supply of a kind of maximum output current of the present invention, comprises Switching Power Supply input, Switching Power Supply output, Switching Power Supply main circuit, voltage sample circuit, integral control circuit and current sampling circuit; Described Switching Power Supply input IN+ and IN-and Switching Power Supply output OUT+ and OUT-are all arranged on Switching Power Supply main circuit, and Switching Power Supply main circuit comprises high frequency transformer T1, power switch pipe Q1, diode D1 and capacitor C 2; Described voltage sample circuit and current sampling circuit are electrically connected with integral control circuit respectively; Described voltage sample circuit comprises the first voltage sampling resistor R1, second voltage sample resistance R6 and voltage sampling regulating resistance RV; Described current sampling circuit comprises current sense resistor RS, and the resistance of current sense resistor RS is 2 milliohms, the primary edge series connection of current sense resistor RS and power switch pipe Q1 and high frequency transformer T1; Described integral control circuit is electrically connected with Switching Power Supply main circuit, and integral control circuit adopts the integrated manipulator that model is UC3843, or has the integrated manipulator of other model of similar functions; Between described current sampling circuit and integral control circuit, be connected with integrated operational amplifier circuit; By integrated operational amplifier, the first integrated transporting discharging resistance R 8, the second integrated transporting discharging resistance R 9, integrated transporting discharging, input resistance R7 and integrated transporting discharging regulating resistance RA form described integrated operational amplifier circuit in the same way; Described the first integrated transporting discharging resistance R 8 one ends are connected on the reverse input end of integrated operational amplifier, other end ground connection; After described the second integrated transporting discharging resistance R 9 and integrated transporting discharging regulating resistance RA series connection, be connected across on the reverse input end and output of integrated operational amplifier; One end ground connection of described current sense resistor RS, the other end by integrated transporting discharging in the same way input resistance R7 be connected to the input in the same way of integrated operational amplifier, wherein integrated operational amplifier employing model is LM358, or has the integrated operational amplifier of other model of similar functions; In other condition all under identical condition, in Fig. 2, single-ended flyback source current sample resistance RS is less, and power switch pipe Q1 ON time is just longer, in the power bracket allowing in main circuit design, when output voltage stabilization, the maximum output current allowing is just larger; Because current sampling resistor RS resistance is milliohm level, and what integrated transporting discharging regulating resistance RA adopted is can fine tuning in a big way in resistance potentiometer, the multiplication factor of integrated operational amplifier circuit is in very large range adjustable, the maximum output current that single-end flyback switching power supply is allowed is adjustable, and electric power output voltage is stablized its output current can be adjusted to its upper limit, for example, in the time that single-end flyback switching power supply output voltage is designed to 36V, output current can reach the maximum current 3A of permission.
Due to the utilization of technique scheme, the present invention compared with prior art has following advantages:
The inverse-excitation type switch power-supply that maximum output current of the present invention is adjustable, the resistance of current sense resistor is milliohm level, and after sampled signal is amplified by integrated operational amplifier circuit, delivers to the current sampling end of integral control circuit again; Because the multiplication factor of integrated operational amplifier circuit is adjustable within a large range, therefore, can realize preferably the adjustability of the maximum output current that Switching Power Supply is allowed, when the output voltage stabilization of Switching Power Supply, output current is adjustable to the upper limit, simultaneously integrated manipulator also can normal response, has improved to a certain extent the versatility of single-end flyback switching power supply product.
Above-described embodiment is only explanation technical conceive of the present invention and feature; its object is to allow person skilled in the art can understand content of the present invention and be implemented; can not limit the scope of the invention with this; all equivalences that Spirit Essence is done according to the present invention change or modify, and all should be encompassed in protection scope of the present invention.
Claims (4)
1. the adjustable inverse-excitation type switch power-supply of maximum output current, comprises Switching Power Supply input, Switching Power Supply output, Switching Power Supply main circuit, voltage sample circuit, integral control circuit and current sampling circuit; Described Switching Power Supply input and Switching Power Supply output are arranged on Switching Power Supply main circuit; Described voltage sample circuit and current sampling circuit are electrically connected with integral control circuit respectively, are provided with current sense resistor in current sampling circuit; Described integral control circuit is electrically connected with Switching Power Supply main circuit; It is characterized in that: between described current sampling circuit and integral control circuit, be connected with integrated operational amplifier circuit.
2. the adjustable inverse-excitation type switch power-supply of maximum output current according to claim 1, is characterized in that: in described current sampling circuit, current sense resistor is selected the resistance of resistance size between 0.2 milliohm to 6 milliohm.
3. the adjustable inverse-excitation type switch power-supply of maximum output current according to claim 1, is characterized in that: by integrated operational amplifier, the first integrated transporting discharging resistance, the second integrated transporting discharging resistance, integrated transporting discharging, input resistance and integrated transporting discharging regulating resistance form described integrated operational amplifier circuit in the same way; Described the first integrated transporting discharging resistance one end is connected on the reverse input end of integrated operational amplifier, other end ground connection; After described the second integrated transporting discharging resistance and the series connection of integrated transporting discharging regulating resistance, be connected across on the reverse input end and output of integrated operational amplifier; Described integrated transporting discharging in the same way input resistance is connected to the input in the same way of integrated operational amplifier.
4. the adjustable inverse-excitation type switch power-supply of maximum output current according to claim 3, is characterized in that: one end ground connection of described current sense resistor, the other end by integrated transporting discharging in the same way input resistance be connected to the input in the same way of integrated operational amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410049002.XA CN103856060A (en) | 2014-02-13 | 2014-02-13 | Flyback switching power supply with adjustable maximum output current |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410049002.XA CN103856060A (en) | 2014-02-13 | 2014-02-13 | Flyback switching power supply with adjustable maximum output current |
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| Publication Number | Publication Date |
|---|---|
| CN103856060A true CN103856060A (en) | 2014-06-11 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410049002.XA Pending CN103856060A (en) | 2014-02-13 | 2014-02-13 | Flyback switching power supply with adjustable maximum output current |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106936423A (en) * | 2015-12-29 | 2017-07-07 | 柳州桂通科技股份有限公司 | Operational amplifier, driving interface, measuring and controlling equipment, drive circuit and driver |
| CN107750425A (en) * | 2016-02-05 | 2018-03-02 | 广东欧珀移动通信有限公司 | For the charging system of terminal, charging method and power supply adaptor, Switching Power Supply |
| US10651677B2 (en) | 2016-02-05 | 2020-05-12 | Guangdong Oppo Mobile Telecommunications Corp., Ltd. | Charging system and charging method, and power adapter and switching-mode power supply |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1165992A (en) * | 1996-03-26 | 1997-11-26 | 雷西昂公司 | Constant on-time architecture for switching regulators |
| US20020057125A1 (en) * | 2000-10-02 | 2002-05-16 | Hironobu Demizu | Switching power supply device |
| CN103199686A (en) * | 2013-03-29 | 2013-07-10 | 朱汝庆 | Switching power supply protective circuit |
| CN203788151U (en) * | 2014-02-13 | 2014-08-20 | 苏州市职业大学 | Fly-back switching power supply with adjustable maximal output current |
-
2014
- 2014-02-13 CN CN201410049002.XA patent/CN103856060A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1165992A (en) * | 1996-03-26 | 1997-11-26 | 雷西昂公司 | Constant on-time architecture for switching regulators |
| US20020057125A1 (en) * | 2000-10-02 | 2002-05-16 | Hironobu Demizu | Switching power supply device |
| CN103199686A (en) * | 2013-03-29 | 2013-07-10 | 朱汝庆 | Switching power supply protective circuit |
| CN203788151U (en) * | 2014-02-13 | 2014-08-20 | 苏州市职业大学 | Fly-back switching power supply with adjustable maximal output current |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106936423A (en) * | 2015-12-29 | 2017-07-07 | 柳州桂通科技股份有限公司 | Operational amplifier, driving interface, measuring and controlling equipment, drive circuit and driver |
| CN107750425A (en) * | 2016-02-05 | 2018-03-02 | 广东欧珀移动通信有限公司 | For the charging system of terminal, charging method and power supply adaptor, Switching Power Supply |
| US10651677B2 (en) | 2016-02-05 | 2020-05-12 | Guangdong Oppo Mobile Telecommunications Corp., Ltd. | Charging system and charging method, and power adapter and switching-mode power supply |
| CN107750425B (en) * | 2016-02-05 | 2020-08-21 | Oppo广东移动通信有限公司 | Charging system and charging method for terminal, power adapter and switching power supply |
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Application publication date: 20140611 |