rad and coolant,

[John Carroll]

Thermostats are made for the cooling system environment and are 
cheap.  Figure out how to insulate and wrap a heating coil around the 
pellet then drive with current.  They are good valves and 
if the logic is correct there will be a built in failsafe. The time 
constant is at least as fast as an iron block.  

How would it work to put louvers on the radiator and open and close 
them?  You could operate a small cylinder or bellows with a tiny 
valve and oil pressure.  If the louvers were closed you would not 
have the inefficiency of pumping losses (air) through the radiator 
when maximum cooling is not needed

John Carroll

 I don't think your control would have to be that precise.  How about 
> using a PM motor geared down to give the torque required and a 
> potentiometer as a position feedback.  You could either use an 'H' 
> bridge to reverse directions or regulate one side of the motor to 6 
> volts and use only two transistors on the other.  It shouldn't have 
> to move often, so effiency shouldn't be a big factor.
> 
> =====================================
> > Date:          Thu, 23 Oct 1997 08:26:00 -0500
> > From:          dave.williams at chaos.lrk.ar.us (Dave Williams)
> > Subject:       Re: rad and coolant,
> > To:            DIY_EFI at coulomb.eng.ohio-state.edu
> > Organization:  The Courts of Chaos * Jacksonville AR USA * 501-985-0059
> > Reply-to:      diy_efi at coulomb.eng.ohio-state.edu
> 
> > 
> > -> Well you could do that, but I was kinda thinking of a ball valve and
> > -> a stepper motor, there's gotta be some out there already. It's also a
> > -> lot easier from the packaging/plumbing standpoint, and I would think
> > -> would afford infinite control within system capabilities.
> > 
> >  I'd love to find something like that.  All of the commercial valves
> > I've seen take more torque than a reasonably-sized stepper can give, so
> > it didn't look practical to cobble something up from pieces.
> >                                                                                          
> > 
> > 
> je
> jengel at fastlane.net
> 
>      "I can resist anything but temptation"
>                                   Mark Twain
> 
> 
John Carroll
jac at wavecom.net