"Alarm is on" Light

[James Sentman]

On Aug 24, 2005, at 2:44 PM, Bill Husler wrote:

> Well, not optimal - at least from my understanding. Transformers  
> are designed to work best with pure sine waves. Even at 100%, the  
> power coming out of a dimmer will not be a pure sine wave. This is  
> the same reason that if you put a fan motor on a dimmer it will  
> hum. Also, since the transformer really wants a sine wave, it will  
> "push back" on the dimmer to try and get what it wants and this  
> will cause the dimmer to run much hotter.
>
> I'm sure others will respond with better discussions, but I'm first!
>


you're first Bill and you rock, you know that :)

You're also right, but not quite emphatic enough.

Dont plug transformers into a lamp dimmer. At least not ones you plan  
to keep around. They make transformers that can withstand the heating  
caused by the chopped up sign wave even when all the way on, but I  
dont think wall worts have all that much thermal mass to deal with it  
and would burn out rather quickly. While I do routinely plug CF bulbs  
into lamp modules for silent operation without problems and there are  
transformers in their ballasts, some brands dont like it at all and  
threaten to burn out in a hurry. I'd definitely use an appliance  
module, but if you're dead set on using a lamp module, then do some  
testing under the load you're going to use it with and be prepared  
with a fire extinguisher and even if it seems to work OK, for it to  
die a week later from mild over heating...

-James