Re: Light bulb power control/dimmer

In article <pan.2007.11.16.21.28.25.395724@xxxxxxxxxxx>, Nobody wrote:
On Fri, 16 Nov 2007 10:55:56 -0500, Tam/WB2TT wrote:

Remember, with cycle skipping the frequency changes. At 10 percent power the
fequency would be 6 Hertz.

The flicker will be 12 Hertz (as opposed to 120Hz at full power). You
don't have to skip whole cycles; half-cycles will do. The polarity doesn't
matter for a resistive load.

In extreme cases, I have seen incandescents visibly flicker from
skipping every other half cycle. The main example is a 4 watt or 7 watt
120V incandescent nightlight with a diode. The thin filament warms and
cools fast enough to have significant 60 Hz flicker. 60 Hz flicker is
sometimes visible.

- Don Klipstein (don@xxxxxxxxx)
.

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