On Jun 15, 6:31*am, Robert Macy wrote:
On Jun 15, 5:29*am, Laurav wrote:

Can one get a control where you can specify the output AC voltage very
accurately, even though the input voltage isn't accurate?
It would be for input to my air turbine. *The air turbine always needs
input voltage much lower than the line voltage. *So the control
wouldn't need step-up circuitry.
With the rheostat that comes with my air turbine, it's very sensitive
to changes in the line voltage.
So I was thinking about bypassing the rheostat instead of buying a
power conditioner and trying to supply very accurate voltage to the
rheostat.
Laura

you didn't say how much power the turbine takes. and if it cycles once
in a while, or a lot.

Two ways come to mind:
1. you can use a passive 'regulator' [by Solar?] It's a resonating
transformer, so you have to specificy 50 or 60Hz. Very large for the
amount of power that goes through them, but they regulate to 1%, which
is around 1 Volt, then you could put a Variac after the regulator and
adjust the voltage pretty exactly. Not much wasted power here.


The cheapest Sola constant voltage transformer still costs several
hundred dollars.