Non-isolated dimming constant-current power supply and control system

Abstract

The invention provides a non-isolated dimming constant-current power supply. The power supply comprises a power supply control IC, a micro control unit MCU and a transformer, wherein the micro controlunit MCU receives a dimming control signal from a user, analyzes dimming power corresponding to the dimming control signal, generates a linear dimming mode control signal if the dimming power is greater than preset power, and generates an interrupted mode control signal if the dimming power is smaller than the preset power; and the power control IC converts a received PWM signal into a linear voltage signal and adjusts the size of output current Io of a load LED by utilizing the linear voltage signal when working in a linear dimming mode, and generates a frequency signal in a preset range according to the received PWM signal, providing the frequency signal to the transformer and adjusting the size of the output current Io of the load LED by utilizing the received PWM signal when working in an interrupted mode. According to the non-isolated dimming constant-current power supply, a linear dimming manner and an interrupted dimming manner are combined to effectively eliminate the noises,which can be sensed by ears, generated by the transformer in the constant-current power supply.

Description

technical field [0001] The invention relates to the field of lighting technology, in particular to a non-isolated dimming constant current power supply and a control system. Background technique [0002] With the continuous development of lighting technology, people's requirements for lighting are getting higher and higher. At present, in order to increase the dimming depth, PWM (Pulse Width Modulation, pulse width modulation) dimming is usually used. When the PWM is high, the power loop of the circuit works, and when the PWM is low, the power loop of the circuit stops working. Since the PWM dimming frequency is within the range that can be perceived by the human ear, the vibration and sound of the transformer is also within the range of the human ear. Usually, transformer impregnation and glue dispensing are used to eliminate noise. This method can only reduce noise. But the noise cannot be eliminated fundamentally, and the human ear can still hear the sound from the power...

AI Technical Summary

Problems solved by technology

Since the PWM dimming frequency is within the range that can be perceived by the human ear, the vibration and sound of the transformer is also within the range of the human ear. Usually, transformer impregnation and glue dispensing are used to eliminate noise. This method can only reduce noise. But the noise cannot be eliminated fundamentally, the human ear can still hear the sound from the power supply

In addition, open-circuit protection is used for the circuit, and the traditional power supply will realize open-circuit protection and restart, and repeated restarts will cause ignition and combustion of the load light source board

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