Tuesday, September 25, 2007

dim prospects

Fluorescent lamps use a gas discharge to generate light, unlike incandescent bulbs that just heat up a filament. The discharge is initiated by a high-voltage pulse generated by the ballast coil in combination with the starter. The ballast coil also controls the power going into the discharge, because gas discharges have negative differential resistance and like to draw very large currents if allowed. Traditional fluorescent lamps also have filaments (yeah, incandescent filaments), which need to heat up to allow electron emission which facilitates the discharge. New 'compact' lamps don't have ballasts, starters or filaments, but rather a high-frequency driver circuit. What all this leads to is that fluorescent lights are not dimmable with the usual 'dimmer switches' that chop the first part of each period of the input voltage waveform to a larger or smaller extent according to the dim setting.
I was looking ways to dim fluorescent lights.
And I found this while googling (using Google Search to find info on the interwebs):

[damned be copy-paste-with-formatting]
I have heard that there is mercury in Compact fluorescent bulbs.

No shit, have you really? :)
Of course there's fucking mercury in all fluorescent lamps, and of course it's toxic :) You thought that just because of all the hype around fluorescents being more power efficient than incandescents (yeah, they really are), they would be environmentally-friendly too?

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