What is Phase Dimming

Phase dimming is to control the conduction time of AC and then dimming, which“clips” part of the sine wave of the alternating current to dim the light. That is to control the time that the mains can provide energy to the lamps in a unit time to regulate the brightness.

Leading edge phase control (LEPC)

Dimming cut-off in the wave on its ascending side, from the beginning (phase cut-off at ignition).

Leading edge dimming is to use TRIAC circuit. The input voltage is chopped from AC phase 0 until the TRIAC is turned on. That is, the front edge is turned on and the zero crossing point is naturally turned off to adjust the light.

Leading edge dimming is to use TRIAC circuit, starting from AC phase 0, the input voltage is chopped, and there is no voltage input until the TRIAC is turned on. The principle is to regulate each half wave of AC to change the sinusoidal waveform, so as to change the effective value of AC current, so as to achieve the purpose of dimming.

The LEPC dimmer has the advantages of high adjustment accuracy, high efficiency, small volume, light weight and easy remote control. It is dominant in the market. Most manufacturers' products are this type of dimmer optical device. Leading edge phase controlled dimmer generally uses thyristor as switching device, so it is also called TRIAC dimmer.

Trailing edge phase control (TEPC)

Dimming by cut-off in the wave on its descending side, from the end cutting backwards (phase cut-off at switch off).

The trailing edge phase cutting control dimmer is made of field effect transistor (FET) or insulated gate bipolar transistor (IGBT) equipment. The trailing edge phase-cut dimmer generally uses MOSFET as the on-off switch device. It is also called MOSFET dimmer, commonly known as "MOS tube".

Thanks to phase dimming technology, we have 24V 150W phase cut dimmable LED driver for sale, which supports both leading edge (Triac) and trailing edge (ELV) dimmer, and can be compatible with the systems of various brands (Philips, Panasonic, Lutron, Simon, ABB,Bunge, Siemens etc.) to achieve a smooth dimming effect. For more details, please visit PHASE CUT LED DRIVER.