Re: Motorized Variac question . . .

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jason by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jasonp-at-btinternet-dot-com>

dwp,

> Another thing to think on:
> Assume the system is up and running.
> Assume the 12vdc supply fails.
> Is there a way to render safe the system with
> not 12v supply?
> (A manual variac can ALWAYS be spun down.  An motorized
> one...)

I have played around with motorised variacs. My interlock used the same 12V
PS as the drive to the motor. I would say connect a power relay in paralell
to the motor drive, that way if anything fails, the power is cut. Always
have a big red button that switches the system OFF.