Re: Triac question

["Nick Austin" <nick.w.austin@xxxxxxxxx>]

On 9/24/07, Stuart Meier <stuartm2007@xxxxxxx> wrote:
>
> Thanks Nick, but I think that as shown it will work when BOTH left and
right
> are on, but not when EITHER (ie OR!) the left lamp, or the right
> lamp...hence two relays (or other devices)

Oops.  I didn't read the question correctly.

The problem with TRIACs is generating the gate voltage.  It needs to
be alternating otherwise the TRIAC will only conduct on one half
cycle.  It must rise rapidly after the zero crossing point otherwise
the TRIAC won't switch on soon enough and it acts as a dimmer.
However it must then stop rising because if the gate voltage is too
high it destroys the TRIAC.  Tricky.

The relay/contactor solution sounds much easier.

Nick.