> I'm in the midst of a similar light dimmer project (110V, 500W,
>Phase
> delay triac). I'm in a quandry over the value of the series
>choke.
> They're either too big and hog board space, too small (seem to
>have no
> effect), or too expensive. Best so far is a home wound 35 turn
>on a
> surplus torroid core (From
http://www.bgmicro.com). I have no specs on
>the
> core and 35 turns is downright painful on the fingers. Anyone
>have any
> rules of thumb on how much filtering is enough??? Some vendors
>spec
> by the milliHenry, others publish current/rise time specs only.
>Any
> suggested sources for parts?
> Joe (Atlanta)
>
>
>
> Big Snip----------
> lighting industry (at least where I work
>
http://www.dovesystems.com) uses phase controlled triacs (or
>solid
> state relays) with a >>>>>>>>>>>series choke<<<<<<<<< to
>limit
> rise time. Again, some use FETs or IGBTs, still switching at 60
>(or
> 50) Hz, but with a slower rise time, making the choke
>unnecessary, but
> suffering low efficiency.
>