CN111818701A - A dimmable high-power LED drive power supply - Google Patents

Abstract

The invention discloses a dimmable high-power LED driving power supply, comprising an input circuit, a main circuit, a control circuit, an optocoupler isolation unit, a Hall current sensor CHB, a single-cycle control unit, a main circuit flyback conversion unit, a constant current Source control unit and PWM dimming unit. The invention can enhance the anti-interference ability of the driving power supply, the output stability, the high output precision and the high power utilization rate.

Description

A dimmable high-power LED drive power supply

【Technical field】

The invention relates to the technical field of LED lamp power supplies, in particular to the technical field of a dimmable high-power LED driving power supply.

【Background technique】

At present, high-power LEDs mainly use AC power supply, and a constant voltage and current are obtained through the converter to supply power to high-power LEDs. However, this method not only has a low power factor, but also cannot effectively suppress the disturbance caused by the input terminal; and dimming is mainly By changing the current flowing through the high-power LED, under different current conditions, the wavelength of light is different, which affects the luminous efficiency. Therefore, this type of circuit has shortcomings such as weak anti-interference ability, poor output stability, low output accuracy, and low power factor. .

[Content of the invention]

The purpose of the present invention is to solve the problems in the prior art, and propose a dimmable high-power LED driving power supply, which can enhance the anti-interference ability of the driving power supply, output stability, high output precision, and high power utilization rate.

In order to achieve the above purpose, the present invention proposes a dimmable high-power LED driving power supply, which includes an input circuit, a main circuit, a control circuit, an optocoupler isolation unit, a Hall current sensor CHB, a single-cycle control unit, and a main circuit flyback. A conversion unit, a constant current source control unit and a PWM dimming unit, the input circuit is provided with a main circuit and a control circuit in parallel, the main circuit is provided with a main circuit flyback conversion unit, the main circuit flyback conversion unit Connected to the single-cycle control unit, the main circuit is provided with an optocoupler isolation unit, the optocoupler isolation unit and the single-cycle control unit, the main circuit is provided with a Hall current sensor CHB, the Hall current sensor The CHB is connected to the single-cycle control unit, the control circuit is provided with a constant-current source control unit, the constant-current source control unit is connected to the single-cycle control unit, and the constant current source control unit and the main circuit flyback conversion unit are connected between A PWM dimming unit is connected.

Preferably, the constant current source control unit adopts an Anti-windup controller, and the constant current source control unit applies the conditional action technology Anti-windup algorithm.

Preferably, the optional models of the Hall current sensor CHB are CHB-25NP and CHB-SP5.

Preferably, the output end of the constant current source control unit is provided with an output switch tube, and the output switch tube is connected to the single-cycle control unit.

Preferably, the optocoupler isolation unit is arranged on the front side of the flyback conversion unit of the main circuit, and the optocoupler isolation unit is not in direct contact with the main circuit.

Preferably, the Hall current sensor CHB is arranged on the front side of the flyback conversion unit of the main circuit, and the Hall current sensor CHB is not in direct contact with the main circuit.

Preferably, the number of the optocoupler isolation unit and the Hall current sensor CHB is at least two.

Beneficial effects of the present invention: The present invention combines the input circuit, the main circuit, the control circuit, the optocoupler isolation unit, the Hall current sensor CHB, the single-cycle control unit, the main circuit flyback conversion unit, the constant current source control unit and the PWM adjustment unit. The optical units are combined together and optimized through experiments. The output voltage is controlled in a single cycle, and the voltage accuracy can be controlled within 1%. When the input voltage is disturbed, the output voltage can be made equal to the voltage reference value within one switching cycle. Effectively suppress the influence of input voltage disturbance, and at the same time, in the single-cycle control process, the subsequent circuit is regarded as a pure resistance, which improves the power factor of the entire circuit. After the output voltage is sampled, it is input to the single-cycle control unit through the optocoupler isolation unit, so that the main The circuit is effectively isolated from the control circuit. The output current detection adopts the Hall current sensor CHB, the optional model is CHB-25NP/SP5, which improves the detection accuracy, effectively avoids the detection error caused by the resistance value change due to the temperature rise, and realizes the main circuit and Isolation of the control circuit, in the constant current control unit strategy, the conditional technology Anti-windup algorithm is applied to maintain the linear continuity of the current at the output end of the constant current source, reduce overshoot, improve control accuracy, and make the system have better dynamic quality And steady-state accuracy, improve the accuracy of the output current, the use of PWM dimming, can achieve smooth adjustment of LED brightness, will not cause color shift phenomenon due to changes in current size, while improving the utilization of electricity.

The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings.

【Description of drawings】

FIG. 1 is a schematic structural diagram of a dimmable high-power LED driving power supply according to the present invention.

【Detailed ways】

Referring to FIG. 1, a dimmable high-power LED driving power supply of the present invention includes an input circuit, a main circuit, a control circuit, an optocoupler isolation unit, a Hall current sensor CHB, a single-cycle control unit, a main circuit flyback conversion unit, A constant current source control unit and a PWM dimming unit, the input circuit is provided with a main circuit and a control circuit in parallel, the main circuit is provided with a main circuit flyback conversion unit, and the main circuit flyback conversion unit is connected to a single cycle The control unit is connected, the main circuit is provided with an optocoupler isolation unit, the optocoupler isolation unit is connected to the single-cycle control unit, the main circuit is provided with a Hall current sensor CHB, and the Hall current sensor CHB is connected to the single-cycle control unit. The cycle control unit is connected, the control circuit is provided with a constant current source control unit, the constant current source control unit is connected with the single cycle control unit, and a PWM is connected between the constant current source control unit and the main circuit flyback conversion unit The dimming unit, the constant current source control unit adopts an Anti-windup controller, the constant current source control unit applies the conditional action technology Anti-windup algorithm, and the Hall current sensor CHB can be selected as CHB-25NP and CHB -SP5, the output end of the constant current source control unit is provided with an output switch tube, the output switch tube is connected to the single-cycle control unit, and the optocoupler isolation unit is arranged on the front side of the flyback conversion unit of the main circuit, so The optocoupler isolation unit is not in direct contact with the main circuit, the Hall current sensor CHB is arranged on the front side of the flyback conversion unit of the main circuit, the Hall current sensor CHB is not in direct contact with the main circuit, and the optocoupler is isolated The number of cells and Hall current sensor CHB is at least two.

The present invention combines the input circuit, the main circuit, the control circuit, the optocoupler isolation unit, the Hall current sensor CHB, the single-cycle control unit, the main circuit flyback conversion unit, the constant current source control unit and the PWM dimming unit together, After experiment optimization, the output voltage is controlled in a single cycle, and the voltage accuracy can be controlled within 1%. When the input voltage is disturbed, the output voltage can be made equal to the voltage reference value within one switching cycle, effectively suppressing the input voltage disturbance band. At the same time, in the single-cycle control process, the subsequent circuit is regarded as a pure resistance, which improves the power factor of the entire circuit. After the output voltage is sampled, it is input to the single-cycle control unit through the optocoupler isolation unit, so that the main circuit and the control circuit are effectively isolated. . The output current detection adopts the Hall current sensor CHB, the optional model is CHB-25NP/SP5, which improves the detection accuracy, effectively avoids the detection error caused by the resistance value change due to the temperature rise, and realizes the main circuit and Isolation of the control circuit, in the constant current control unit strategy, the conditional technology Anti-windup algorithm is applied to maintain the linear continuity of the current at the output end of the constant current source, reduce overshoot, improve control accuracy, and make the system have better dynamic quality And steady-state accuracy, improve the accuracy of the output current, the use of PWM dimming, can achieve smooth adjustment of LED brightness, will not cause color shift phenomenon due to changes in current size, while improving the utilization of electricity.

The above-mentioned embodiments are illustrative of the present invention, not limitations of the present invention, and any simple transformation scheme of the present invention belongs to the protection scope of the present invention.

Claims (7)

1. The utility model provides a high-power LED drive power supply of can adjusting luminance which characterized in that: comprises an input circuit, a main circuit, a control circuit, an optical coupling isolation unit, a Hall current sensor CHB, a single-period control unit, a main circuit flyback conversion unit, a constant current source control unit and a PWM dimming unit, the input circuit is provided with a main circuit and a control circuit in parallel, the main circuit is provided with a main circuit flyback conversion unit, the main circuit flyback conversion unit is connected with the single-period control unit, the main circuit is provided with an optical coupling isolation unit, the optical coupling isolation unit and the single-period control unit, the main circuit is provided with a Hall current sensor CHB, the Hall current sensor CHB is connected with a single-period control unit, a constant current source control unit is arranged on the control circuit, the constant current source control unit is connected with the single-period control unit, and a PWM dimming unit is connected between the constant current source control unit and the main circuit flyback conversion unit.

2. The dimmable high power LED driving power supply of claim 1, wherein: the constant current source control unit adopts an Anti-window controller, and applies a conditional action technology Anti-window algorithm.

3. The dimmable high power LED driving power supply of claim 1, wherein: the Hall current sensor CHB can be selected from models CHB-25NP and CHB-SP 5.

4. The dimmable high power LED driving power supply of claim 1, wherein: the output end of the constant current source control unit is provided with an output switch tube, and the output switch tube is connected with the single-period control unit.

5. The dimmable high power LED driving power supply of claim 1, wherein: the optical coupling isolation unit is arranged on the front side of the main circuit flyback conversion unit and is not in direct contact with the main circuit.

6. The dimmable high power LED driving power supply of claim 1, wherein: the Hall current sensor CHB is arranged on the front side of the main circuit flyback conversion unit, and is not in direct contact with the main circuit.

7. The dimmable high power LED driving power supply of claim 1, wherein: the number of the optical coupling isolation units and the number of the Hall current sensors CHB are at least two.

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