Constant-current constant-power LED power supply control circuit

Abstract

The utility model discloses a kind of LED power supply control circuit of constant current constant power, including AC input terminal, with the rectifier filter circuit being connected with AC input terminal, with the constant current circuit being connected with rectifier filter circuit, with the transformer circuit being connected with constant current circuit and with the LED power supply output circuit being connected with transformer circuit, still including with the constant power control circuit being connected with the constant current circuit;The constant power control circuit includes first unidirectional diode, first resistance, second unidirectional diode, third resistance, second resistance and first capacitor.The utility model's structure setting is reasonable, it can achieve constant current purpose by constant current circuit, and also can achieve the purpose of constant power by constant power control circuit, improve its applicability stability and effectiveness to a certain extent, guarantee the reliability of luminaire control, and applicability is strong.

Description

Technical Field

[0001] This utility model belongs to the field of LED power supply circuit technology, specifically relating to a constant current and constant power LED power supply control circuit. Background Technology

[0002] In the lighting industry, constant current power supplies are a common electrical structure in lamps. Existing constant current power supplies include an AC input terminal, a rectifier and filter circuit connected to the AC input terminal, and a constant current circuit and a transformer circuit connected to the rectifier and filter circuit. Although they can meet the general usage requirements, they cannot achieve constant current and constant power functions, which to some extent affects their applicability, stability, and effectiveness, making it difficult to meet market demands. Utility Model Content

[0003] The purpose of this invention is to provide a constant current and constant power LED power supply control circuit with a reasonable structure that can achieve constant power effect.

[0004] The technical solution to achieve the purpose of this utility model is a constant current and constant power LED power supply control circuit, including an AC input terminal, a rectifier and filter circuit connected to the AC input terminal, a constant current circuit connected to the rectifier and filter circuit, a transformer circuit connected to the constant current circuit, and an LED power supply output circuit connected to the transformer circuit, and also includes a constant power control circuit connected to the constant current circuit.

[0005] The constant power control circuit includes a first unidirectional diode, a first resistor, a second unidirectional diode, a third resistor, a second resistor, and a first capacitor;

[0006] The first unidirectional diode, the first resistor, the second unidirectional diode, and the third resistor are connected in series, and the third resistor is connected to the CS pin of the constant current chip in the constant current circuit. The positive terminal of the first unidirectional diode is connected to the VCC terminal of the constant current chip in the constant current circuit.

[0007] The first resistor is connected to the negative terminal of the first unidirectional diode, and the positive terminal of the second unidirectional diode is connected to the first resistor;

[0008] The first capacitor and the second resistor are connected in parallel. One end of the first capacitor and the second resistor are connected to the connection between the first resistor and the second unidirectional diode, and the other end of the first capacitor and the second resistor are grounded.

[0009] When in use, the secondary winding of the transformer is input to the constant power control circuit, rectified into DC by the first unidirectional diode D1, then rectified and filtered by the first resistor R1 and the first capacitor C1, then divided by the second resistor R2, isolated by the second unidirectional diode D2, and then current-limited by the third resistor R3 and output to the CS current detection pin of the original constant current circuit chip, automatically adjusting the output current to achieve constant current and constant power function.

[0010] The control logic works because the secondary winding and the secondary output winding are on the same transformer. Therefore, when the output voltage rises and the power rises, the voltage of the secondary winding also rises. After being shaped by the constant power control circuit, it is output to the CS current detection pin of the constant current chip, causing the voltage of the CS current detection pin to rise as well, thereby reducing the output current. In other words, when the output voltage rises, the output current decreases, and the power is equal to the product of voltage and current, thus achieving constant power.

[0011] This utility model has positive effects: its structure is reasonably designed, and it can achieve constant current through a constant current circuit and constant power through a constant power control circuit, which improves its applicability, stability and effectiveness to a certain extent, ensures the reliability of lamp control, and has strong applicability. Attached Figure Description

[0012] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0013] Figure 1 This is a schematic diagram of the circuit structure of this utility model.

[0014] Figure label: AC input terminal 1, rectifier and filter circuit 2, constant current circuit 3, transformer circuit 4, LED power output circuit 5, constant power control circuit 6. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] Example

[0017] See Figure 1As shown, a constant current and constant power LED power supply control circuit includes an AC input terminal 1, a rectifier and filter circuit 2 connected to the AC input terminal, a constant current circuit 3 connected to the rectifier and filter circuit, a transformer circuit 4 connected to the constant current circuit, and an LED power output circuit 5 connected to the transformer circuit. It also includes a constant power control circuit 6 connected to the constant current circuit. In this embodiment, the AC input terminal is connected to the mains power supply. The rectifier and filter circuit, the constant current circuit, and the transformer circuit are all conventional circuits of the prior art, simply applied. The constant current circuit is mainly implemented using a constant current chip, and the model of the constant current chip is a common model, therefore not described in detail.

[0018] In this embodiment, the constant power control circuit includes a first unidirectional diode D1, a first resistor R1, a second unidirectional diode D2, a third resistor R3, a second resistor R2, and a first capacitor C1. During connection, the first unidirectional diode D1, the first resistor R1, the second unidirectional diode D2, and the third resistor R3 are connected in series, and the third resistor R3 is connected to the CS pin of the constant current chip in the constant current circuit 3. The anode of the first unidirectional diode D1 is connected to the VCC terminal of the constant current chip in the constant current circuit 3. The first resistor R1 is connected to the cathode of the first unidirectional diode D1, and the anode of the second unidirectional diode D2 is connected to the first resistor R1. Furthermore, the first capacitor C1 and the second resistor R2 are connected in parallel, with one end of the first capacitor C1 and the second resistor R2 connected at the junction of the first resistor R1 and the second unidirectional diode D2, and the other end of the first capacitor C1 and the second resistor R2 grounded.

[0019] When in use, the secondary winding of the transformer is input to the constant power control circuit, rectified into DC by the first unidirectional diode D1, then rectified and filtered by the first resistor R1 and the first capacitor C1, then divided by the second resistor R2, isolated by the second unidirectional diode D2, and then current-limited by the third resistor R3 and output to the CS current detection pin of the original constant current circuit chip, automatically adjusting the output current to achieve constant current and constant power function.

[0020] The control logic works because the secondary winding and the secondary output winding are on the same transformer. Therefore, when the output voltage rises and the power rises, the voltage of the secondary winding also rises. After being shaped by the constant power control circuit, it is output to the CS current detection pin of the constant current chip, causing the voltage of the CS current detection pin to rise as well, thereby reducing the output current. In other words, when the output voltage rises, the output current decreases, and the power is equal to the product of voltage and current, thus achieving constant power.

[0021] This utility model has positive effects: its structure is reasonably designed, and it can achieve constant current through a constant current circuit and constant power through a constant power control circuit, which improves its applicability, stability and effectiveness to a certain extent, ensures the reliability of lamp control, and has strong applicability.

[0022] The standard parts used in this embodiment can be purchased directly from the market, and the non-standard structural parts described in the instruction manual can also be processed without any doubt based on existing technical common sense. At the same time, the connection methods of each component adopt mature conventional methods in the existing technology, and the machinery, parts and equipment all adopt conventional models in the existing technology, so they will not be described in detail here.

[0023] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. However, these obvious variations or modifications derived from the essential spirit of this utility model still fall within the protection scope of this utility model.

Claims

1. A constant current constant power LED power supply control circuit comprising AC input terminals, a rectification filter circuit connected to the AC input terminals, a constant current circuit connected to the rectification filter circuit, a transformer circuit connected to the constant current circuit and an LED power supply output circuit connected to the transformer circuit, characterized in that: It also includes a constant power control circuit connected to the constant current circuit; The constant power control circuit includes a first unidirectional diode, a first resistor, a second unidirectional diode, a third resistor, a second resistor, and a first capacitor; The first unidirectional diode, the first resistor, the second unidirectional diode, and the third resistor are connected in series, and the third resistor is connected to the CS pin of the constant current chip in the constant current circuit. The positive terminal of the first unidirectional diode is connected to the VCC terminal of the constant current chip in the constant current circuit. The first resistor is connected to the negative terminal of the first unidirectional diode, and the positive terminal of the second unidirectional diode is connected to the first resistor; The first capacitor and the second resistor are connected in parallel. One end of the first capacitor and the second resistor are connected to the connection between the first resistor and the second unidirectional diode, and the other end of the first capacitor and the second resistor are grounded.

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