Sine Wave Dimmers

Forward phase reverse phase and sinewave dimming.

Sine wave dimmers.

While a typical 800us reverse phase ibgt dimmer is more efficient then 790us high rise scr dimmer no choke loss its efficiency is very similar to sinewave. It has been suggested that sine wave dimmers are the party the dimmer manufacturers gave but nobody came in the usa. A large amount of heat is produced in these dimmers during the transitions rise or fall time since the igbts are operated in their linear region. As flourescent lights need a minimum voltage and both compact flourescents and leds use electronics which rectifies the peak voltage provided a variable amplitude sine wave would fail to dim all of these types but in a slightly different way that the phase shift dimmer fails to dim them.

The interruptions occur at a rate of 120 times per second or twice the frequency at which alternating current delivers electricity over power lines. The following examples will make this clear. Typically a tungsten lamp although other loads like fluorescent lamps or leds may be dimmed as well there are three methods of dimming in common use. Dimmers are producing triplen harmonics.

It clips part of the sine wave of the alternating current to dim the light. When the current changes direction the light bulb circuit is automatically shut off. In fact they re also called phase cut dimmers because the interruptions in current create cuts in the ac sine wave. The change in direction takes place when there s zero voltage which happens twice in every cycle 120 times per second.

Sine wave dimmers are more efficient then comparable ssr and scr dimmers they are able to operate much faster be much quieter and still achieve the same efficiency. This page has been seen 1 518 times. On the contrary a reverse phase dimmer cuts out a portion of the ac waveform at the trailing edge in order that the dimmer turns off part way through the sine wave. With a dimmer switch this regular sine wave or curve is chopped up deliberately.

Leading edge phase control. Sine wave dimmers vebill military 18 may 14 08 32 there are brazillions of 12 vdc led lighting solutions systems equipment available cheap on ebay it would be up to you to determine if the existing wiring could be reused or if this is a non starter due to the wiring. Dimming is the process of controlling the amount of electrical power to a light source. Phase control is a dimming technique based on the electric wire that is often used for halogen and incandescent lamps.