DIMPC

DIMPC is Luxonic’s Phase-cut dimming system.

Before LED technology was developed, dimming halogen lamps via the phase-cut dimming method with wall switches was the norm. These controls can still be utilized with the latest LED products, but the light source, the control gear and wall switch (dimmer) must be compatible. Phase-cut dimming can be implemented without the requirement of an additional control wire. A dimmer has to be connected in series between one of the mains wires and the equipment.

When engaged, the wall switch (dimmer) alters part of the mains voltage sinusoidal waveform to a greater or lesser extent in order to dim luminous flux even from 1% to 100%, depending on the dimmer and driver used. There are two different types of phase-cut dimming. The two versions are known as ‘Leading-edge dimming and Trailing-edge dimming.

 

Different Phase-cut Dimming Types

Leading-edge dimming is when the light source is energized only during the last portion of each power-line half cycle. This type of dimming is inexpensive and is suitable for a wide variety of light sources, including some types of LED.

Trailing-edge dimming is when the light source is energized during the initial portion of each power-line half cycle. This type of dimming is also compatible with a wide range of light sources and usually produces less interference and noise.

 

See Fig 1 & 2 below for visual illustration of phase-cut dimming in operation.

 

phase-cut dimming diagram

 

 

It is worth noting that Phase-cut dimmers vary significantly between vendors. In fact a survey of 64 dimmers revealed that the minimum firing angle ranged from 17° to 72° and the maximum firing angle from 104° to 179°.