alt.energy.renewable

Anthony Matonak wrote:
>
> Morris Dovey wrote:
> > Mike wrote:
> >
> >
> >
> >> Where the displacer is free floating you'd maybe use a couple of
> >> displacement transducers and a lot of pc processing, for the solar
> >> fluidyne I'm stuck at the moment of what you could do - Maybe use
> >> clear pipes and a video camera and sample the levels at the frame
> >> rate?
> >
> > I think your pressure transducer idea is a winner. I've been
> > scratching my head over the idea of building tubular capacitors
> > that could fit inside the vertical tubes to see if I could
> > measure the height (depth) of the water by measuring a
> > capacitance variance in real time.
> >
> > If I can extract pressure and water levels, I should be able to
> > derive what I /think/ I'm after. :-)
>
> You might be able to use ultrasonic range finders like they
> use on car backup sensors and robot kits. Mount them at the
> top of the tube pointing down and they should measure the
> distance to the water level.

I'd like to sample at ~1 millisecond intervals. Do you think they
can handle that rate? I would guess probably not (but I guess
wrong all the time ).

> I think the pressure inside your fluidyne will be the same
> everywhere at any one moment so a single pressure transducer
> mounted anywhere inside should work.

I don't think so. Cycles in hot and cold heads need to be out of
sync in order for the engine to run. Part of what I want this
lash-up for is to allow tuning for a 90-degree phase difference.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/