Re: Help with AC switch - how can I make it gradually turn voltage up?

routman@xxxxxxxxx wrote:
> I have a pump which runs on AC. When I flip the power switch on, I
> need pump to slowly turn on. So I basically need the AC voltage to
> gradually go from 0V to 120V (rms) over the course of around 1 second.
> But I cannot do it manually (I cant use a turnpot or anything like
> that). It needs to be done all on its own, just by flicking the AC
> switch on. What is the easiest way to do this? Thanks.

The thermistor suggestion - probably - won't work.
Most AC pumps are synchronus - and only really work at all at near
nominal voltage.

What sort of pump is it?

It may be possible to slowly ramp up the speed using a $100 (assuming
you're in the US) or so controller.
It may be more practical to do hydraulically.
.