A current sharing circuit using a current sharing inductor

Abstract

The present invention provides a current sharing circuit using a current sharing inductor, including a converter. The DC positive pole output by the converter is connected to a first current sharing device, and the DC negative pole output by the converter is connected to a second current sharing device. One output terminal of the first current sharing device is sequentially connected to a first diode D1, a first load LED1, a sampling resistor RES, and one output terminal of the second current sharing device. The other output terminal of the first current sharing device is sequentially connected to a second diode D2, a second load LED2, and the other output terminal of the second current sharing device. It further includes a first filter capacitor EC1 and a second filter capacitor EC2. The first filter capacitor EC1 is connected in parallel with the second load LED2, and the second filter capacitor EC2 is connected in parallel with the first load LED1 and the sampling resistor RES. Through the present invention, the problems of low current sharing accuracy, high cost for multi-channel output expansion, and large system size existing in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of driving power supplies, and particularly to a current sharing circuit using a current sharing inductor. Background Art

[0002] Currently, the current sharing circuits applied to LED driving power supplies generally adopt the following methods:

[0003] 1. Passive current sharing scheme one: Current sharing is achieved by connecting capacitors in series in all branches. The structure is simple and easy to expand. Although this scheme has a simple structure and is convenient for expansion, it is only suitable for LLC topologies and requires the use of capacitors with better precision to achieve. It can be used when the requirement for current sharing effect is not high.

[0004] 2. Active current sharing scheme: Active devices such as switching transistors and certain control circuits are used to form a current regulator to achieve current control. Although this scheme has high current sharing accuracy, it also has disadvantages. For multi-output expansion, its cost is high and the system is large.

[0005] 3. Passive current sharing scheme two: It is a scheme that uses a current sharing transformer to achieve multi-path current sharing. It uses the connection between coupled inductors to couple the change of one circuit to another to achieve current sharing. However, the deviation of the inductor value of the transformer and the deviation of the output voltage will both affect the current sharing accuracy. Summary of the Invention

[0006] The present invention provides a current sharing circuit using a current sharing inductor to solve the problems of low current sharing accuracy and complex and large multi-output expansion structure in the prior art.

[0007] To solve the above technical problems, the present invention provides a current sharing circuit using a current sharing inductor, including a converter. The positive DC output of the converter is connected to a first current shunt, and the negative DC output of the converter is connected to a second current shunt. One output terminal of the first current shunt is sequentially connected to a first diode D1, a first load LED1, a sampling resistor RES, and one output terminal of the second current shunt. The other output terminal of the first current shunt is sequentially connected to a second diode D2, a second load LED2, and the other output terminal of the second current shunt. It also includes a first filter capacitor EC1 and a second filter capacitor EC2. The first filter capacitor EC1 is connected in parallel with the second load LED2, and the second filter capacitor EC2 is connected in parallel with the first load LED1 and the sampling resistor RES.

[0008] It also includes a controller, an isolation device, and a detection feedback circuit connected in series. The controller is connected to the converter, and the detection feedback circuit is connected between the first load LED1 and the sampling resistor RES.

[0009] The first current-sharing inductor and the second current-sharing inductor are respectively a first current-sharing inductor and a second current-sharing inductor. The different-named ends of the first winding of the first current-sharing inductor are sequentially connected to the different-named end of the second winding of the first diode D1, the first load LED1, the sampling resistor RES, and the second current-sharing inductor.

[0010] The same-named ends of the second winding of the first current-sharing inductor are sequentially connected to the same-named end of the first winding of the second diode D2, the second load LED2, and the second current-sharing inductor.

[0011] The same-named end of the first winding of the first current-sharing inductor and the different-named end of the second winding of the first current-sharing inductor are connected to the DC positive pole output by the converter; the different-named end of the first winding of the second current-sharing inductor and the same-named end of the second winding of the second current-sharing inductor are connected to the DC negative pole output by the converter.

[0012] The different-named end of the second winding of the second current-sharing inductor is grounded.

[0013] A sampling point IS is provided between the first load LED1 and the sampling resistor RES.

[0014] The beneficial effects brought by the present invention: The current-sharing circuit using current-sharing inductors in the present invention has high current-sharing accuracy, is convenient for multi-channel output expansion, has a small volume and low cost, and the use of two current-sharing inductors makes the layout more flexible. Description of the Drawings

[0015] Figure 1 is a system block diagram of the current-sharing circuit using current-sharing inductors according to the present invention;

[0016] Figure 2 is a hardware connection diagram of the current-sharing circuit using current-sharing inductors according to the present invention. Detailed Embodiments

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments.

[0018] As Figure 1-2As shown in the figure, an embodiment of the present invention provides a current sharing circuit using a current sharing inductor, including a converter. The positive pole of the DC output by the converter is connected to a first current shunt, and the negative pole of the DC output by the converter is connected to a second current shunt. One output terminal of the first current shunt is sequentially connected to a first diode D1, a first load LED1, a sampling resistor RES, and one output terminal of the second current shunt. The other output terminal of the first current shunt is sequentially connected to a second diode D2, a second load LED2, and the other output terminal of the second current shunt. It further includes a first filter capacitor EC1 and a second filter capacitor EC2. The first filter capacitor EC1 is connected in parallel with the second load LED2, and the second filter capacitor EC2 is connected in parallel with the first load LED1 and the sampling resistor RES.

[0019] Furthermore, it further includes a controller, an isolation device, and a detection feedback circuit connected in series in sequence. The controller is connected to the converter, and the detection feedback circuit is connected between the first load LED1 and the sampling resistor RES.

[0020] Furthermore, the first current shunt and the second current shunt are respectively a first current sharing inductor and a second current sharing inductor. The different-named ends of the first winding of the first current sharing inductor are sequentially connected to the different-named ends of the first diode D1, the first load LED1, the sampling resistor RES, and the second winding of the second current sharing inductor.

[0021] Furthermore, the same-named ends of the second winding of the first current sharing inductor are sequentially connected to the same-named ends of the second diode D2, the second load LED2, and the first winding of the second current sharing inductor.

[0022] Furthermore, the same-named end of the first winding of the first current sharing inductor and the different-named end of the second winding of the first current sharing inductor are connected to the positive pole of the DC output by the converter; the different-named end of the first winding of the second current sharing inductor and the same-named end of the second winding of the second current sharing inductor are connected to the negative pole of the DC output by the converter.

[0023] Furthermore, the different-named end of the second winding of the second current sharing inductor is grounded.

[0024] Furthermore, a sampling point IS is provided between the first load LED1 and the sampling resistor RES.

[0025] The first load LED1 and the second load LED2 represent two loads in the circuit. The first filter capacitor EC1 and the second filter capacitor EC2 are the filter capacitors for the two output paths. The sampling resistor RES serves as the sampling part of the output current. The first current-sharing inductor is placed on the positive line of the circuit and is divided into two branches through the first winding and the second winding, which are respectively connected to the first diode D1 and the second diode D2. After being rectified by the first diode D1 and the second diode D2, they are respectively connected to the energy storage filter capacitors, the first filter capacitor EC1 and the second filter capacitor EC2, and after electrolytic filtering, they are respectively connected to the loads, the first load LED1 and the second load LED2.

[0026] In summary, the current-sharing circuit using the current-sharing inductor of the present invention has high current-sharing accuracy, is convenient for multi-path output expansion, has a small volume and low cost, and the use of two current-sharing inductors makes the layout more flexible.

[0027] The above are only the embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A current-sharing circuit using a current-sharing inductor, characterized in that: It includes a converter. The DC positive pole output by the converter is connected to a first current-sharing device, and the DC negative pole output by the converter is connected to a second current-sharing device. One output terminal of the first current-sharing device is sequentially connected to a first diode D1, a first load LED1, a sampling resistor RES, and one output terminal of the second current-sharing device. The other output terminal of the first current-sharing device is sequentially connected to a second diode D2, a second load LED2, and the other output terminal of the second current-sharing device. It also includes a first filter capacitor EC1 and a second filter capacitor EC2. The first filter capacitor EC1 is connected in parallel with the second load LED2, and the second filter capacitor EC2 is connected in parallel with the first load LED1 and the sampling resistor RES; The first current-sharing device and the second current-sharing device are respectively a first current-sharing inductor and a second current-sharing inductor. The different-named ends of the first winding of the first current-sharing inductor are sequentially connected to the different-named ends of the first diode D1, the first load LED1, the sampling resistor RES, and the second winding of the second current-sharing inductor; The same-named ends of the second winding of the first current-sharing inductor are sequentially connected to the same-named ends of the second diode D2, the second load LED2, and the first winding of the second current-sharing inductor; The same-named end of the first winding of the first current-sharing inductor and the different-named end of the second winding of the first current-sharing inductor are connected to the DC positive pole output by the converter; the different-named end of the first winding of the second current-sharing inductor and the same-named end of the second winding of the second current-sharing inductor are connected to the DC negative pole output by the converter; It also includes a controller, an isolation device, and a detection feedback circuit connected in series in sequence. The controller is connected to the converter, and the detection feedback circuit is connected between the first load LED1 and the sampling resistor RES.

2. The current-sharing circuit using a current-sharing inductor according to claim 1, characterized in that, The different-named end of the second winding of the second current-sharing inductor is grounded.

3. The current-sharing circuit using a current-sharing inductor according to claim 1, characterized in that, A sampling point IS is provided between the first load LED1 and the sampling resistor RES.

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