Sine Wave Dimmer Circuit

4 in dimmers that chop the sine wave such as scr or ssr dimmer the lights would hum the loudest when dimmed to 50 because sine waves peak half way through their cycle as the reach their crest and begin returning to 0v.

Sine wave dimmer circuit.

Another capacitively coupled bridge with the caps acting as droppers from. This 555 timer is in astable mode. The mains is bridge rectified 35a for the dc bus which is allowed to swing with the full wave rectified waveform as it only has a 100nf cap across its output. This is because line voltage dimming leds react to the hard phase angle that s present in both forward and reverse phase dimming which sinewave dimmers were designed to eliminate.

The sine wave generator circuit that we will build is shown below. Pin 1 is grounded. Sine wave and dc dimming. The breadboard schematic of the above circuit is shown below.

I found this circuit of a sinewave dimmer. So first for the power requirements of this circuit we use 4 5v to the 555 timer chip. This 4 5v goes to pin 8 and pin 4. Power is off during the initial part of each half cycle and then turns on.

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. This peak half way through the wave forms means that the amplitude difference between on and off is greatest when the dimmer is set to 50 and therefore the harmonics for. 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. Everything is referred to the bridge terminal as local 0v.

A notable disadvantage of sinewave dimmers is that they don t interact well with led loads it s likely that sinewave dimmed leds won t dim at all.