How does triac constant current dimming driver achieve precise dimming and energy saving?
Publish Time: 2025-03-21
Triac constant current dimming driver achieves precise dimming and energy saving of LED lamps by precisely controlling the current.1. Working principleSCR dimming uses the chopping function of thyristor to adjust the input voltage of the dimming driver power supply, thereby changing the output current. Since the brightness of LED lamps depends on the current, by precisely controlling the current flowing through the LED, its brightness can be precisely adjusted.2. Precise dimming implementation methodZero-crossing detection: SCR (SCR) is a high-power electrical component whose turn-on and turn-off depend on the zero-crossing point of the voltage. Therefore, an accurate zero-crossing detection circuit is required to determine the zero-crossing moment of the AC input. Optocouplers are usually used for zero-crossing detection to ensure that the thyristor is triggered to turn on or off at the right time.Trigger circuit: In order to control the conduction of the thyristor, a trigger circuit is required. This circuit usually consists of a trigger diode isolated by an optocoupler and a trigger resistor. The design of the trigger circuit needs to ensure that sufficient trigger voltage is provided at the zero-crossing moment to ensure reliable conduction of the thyristor. By adjusting the resistance value in the trigger circuit, the conduction angle of the thyristor can be changed, thereby achieving precise adjustment of the brightness of the LED lamp.Multi-mode dimming: Modern dimming systems may need to support multiple dimming modes, such as 0-10V dimming, PWM dimming, and thyristor dimming. The triac constant current dimming driver should be able to flexibly switch between different dimming modes to meet different application requirements.3. Energy-saving implementation methodsHigh-efficiency power factor correction (PFC): During the dimming process, the sinusoidal waveform of the input voltage may be destroyed due to the change in the conduction angle of the thyristor, thereby reducing the power factor. In order to improve the energy efficiency and stability of the system, the triac constant current dimming driver usually adopts power factor correction technology, such as single-stage PFC control, to ensure that a high power factor is maintained during the dimming process, thereby reducing energy waste.Intelligent dimming strategy: By using preset dimming strategies or automatically adjusting the brightness of LED lights according to ambient light changes, more intelligent energy-saving effects can be achieved. For example, in a well-lit environment, the brightness of the LED light can be reduced to reduce energy consumption; when high-brightness lighting is required, the brightness of the LED light can be increased to meet lighting needs.In summary, the triac constant current dimming driver achieves precise dimming and energy saving of LED lights by precisely controlling current and adopting efficient power factor correction technology. In actual applications, attention should be paid to load matching, heat dissipation design, and noise control to ensure stable operation and dimming effect of the equipment.
