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Tue 12 Dec, 2006 09:25 am
According to my How Stuff Works references, A three-way light bulb has two filaments in it and can burn one or the other or both filaments to produce low, medium and high lighting levels.
A touch-sensitive lamp uses capacitance to regulate electrons flowing to the light bulb. When you touch the lamp, your body adds to the capacity, and it takes more electrons to fill you and the lamp, and the circuit detects that difference.
Touch sensitive lamps have three brightness settings that do not require a three-way bulb. The circuit is changing brightness of the lamp by changing the duty cycle of the power reaching the bulb, thus changing brightness levels.
Question: If you were to place a 3-way light bulb on a touch-sensitive lamp, would you then have more than three brightness levels?
I believe you'd need to be able to mechanically switch the lightbulb to activate the bulb's filament options. Then, would you be able to touch the lamp to alter the brightness level of each of those flilament options?
I think it would not work because you need to be able to mechanically switch the lightbulb and each time you did that, the touch-sensitive circut would change the power level reaching the bulb.
Anyone able to think of a way to make that work so you end up with a touch-sensitive lamp containing a 3-way bulb and three brightness levels for each of the bulb's filament combinations? If it works, you'd end up with a 9-level lighting combination.
I'm thinking a dimmer switch would be a much better solution but just thought I'd ask if this was even possible scientifically.
3-way lamps have a special bulb and socket incorporating 2 power contacts (one for each filament segment) instead of a conventional bulb's single power contact, and a switch configuration which routes power to one, the other, both, or none of the filaments. An outboard dimmer control into which the 3-way lamp is plugged could be used to vary the voltage applied to the lamp's switch, which of course would vary the brightness (and color temperature) of whichever filaments were energized. There might be impact on overall filament life; dunno, haven't tried it. Having only a conventional, single power contact, a dimmer or tap control the bulb screws into will affect only the primary filament of a 3-way bulb, since the secondary filament never would be powered.
Yeah, that's what I figured. The three-way bulb is more a function of mechanics than science. I spent a few hours thinking about ways to make a combination of the both work and couldn't think of one so thought I'd put forth the concept here and see if anything flew. That problem with the primary filament was the stumbling block for me too.
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