[balloon-makers] autopilot valve.

[Mark Caviezel]

David: 
thanks for the reminder, I've seen your write-up
before, but should probably re-review it. 
I'm going to try a GPS based auto pilot.   
And I am also interested in finding a valve that can
be run off of something less than a lead-acid battery.
  A friend of mine makes a very cool PIC device which
will apply full current for 20 milliseconds or so,
then drop back to a 15% duty cycle pulse width
modulation to keep a solenoid valve open.   This means
much less total energy consumption, and the valve
doesn't heat up.   This is basically identical to how
solenoid valves are  driven on many satellites.  

- Mark Caviezel 



--- David Barker <private e-mail address> wrote:

> I produced an autopilot rather more than 20 years
> ago, which worked. You
> might get some ideas for your own auto from the
> section on my web site which
> describes the theory etc.
> 
> Power consumption of the auto is negligible, the
> big(ish) battery is
> needed to power the electric valves.  Size including
> the control panel but
> excluding the required vario and battery and box is
> about 4" x 2" x 2" and
> weight is about 3 oz.  (The control knobs alone
> probably take up half the
> final weight!) It can be programmed for level flight
> or any rate of climb or
> descent up to 600 fpm.
> 
> Best regards
> 
> David Barker
> On the road in Canada
> 
> http://dbarker.club.fr
> 
> 
> 
> On Thursday, August 31, 2006 9:54 AM ,
> Mark Caviezel wrote:
> 
> > Robert:
> > this is just a 'for fun' project, maybe for use
> during
> > a long jump flight.
> > I've seen pics of Comstock's autopilot, about as
> large
> > as a shoebox, power consumption unknown.   My
> > autopilot will be much smaller, lighter, probably
> > lower power consumption, and eventually with
> > programmable ascent/descent rates.
> >
> > I am open to suggestions for suitable electric
> > blastvalves.
> >
> > - Mark Caviezel
> >
> >
> >
> >
> >
> > --- Robert Kerr <private e-mail address> wrote:
> >
> >> Mark,
> >>
> >> What is the intended project?
> >>
> >> Bruce Comstock already has built an autopilot
> unit
> >> for Hot Air Balloon use,
> >> so you might check with him.
> >>
> >>
> >> Robert Kerr
> 
> -
> "Balloon-makers" is archived at
> http://www.hombc.org/balloon-makers/
> 

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