ODP: 3rd Re: ODP: optical pots 2

[David Halliday (Volt Computer)]

It is thermal - the strip has an electrical resistance and is coated with a
temperature-sensitive liquid crystal material.  The LC changes color as it
heats up.  The color progresses up the scale because the resistance changes
over length.

Only problem with using it as an indicator is that it consumes a huge amount
of power ( by design ) and it's response time is very very slow.



You want to test the battery under load anyway so this works out to be a
very cheap and accurate solution.




-----Original Message-----
From: Paul van Nugteren [mailto:PMvanNugteren at gmx.net]
Sent: Tuesday, May 18, 1999 3:58 AM
To: Roman Sowa
Cc: synth-diy at mailhost.bpa.nl; synth-diy at mailhost.bpa.nl
Subject: Re: ODP: 3rd Re: ODP: optical pots 2


> This would be so so very cool!
> I don't know how they do it, but I suspect you can use the strip
> only few times. Besides I have no idea how to get its formula.
> Duracell won't give it away, I'm sure
> 
> How about motorized pot? Only to drive indicator, not to use it
> as a knob. Or any other kind of motor :-)
> 
> Roman
> 


Guess what? It's a chemical reaction controlled by a current! So al we
would have to do is to put a current or voltage to the strip which has
approx
the same level as the knob has. 

Any chemists on the list?


Thanks,

Paul van Nugteren

> > -----Oryginalna wiadomo¶æ-----
> > Od:	P.M. van Nugteren [SMTP:PMvanNugteren at gmx.net]
> > Wys³ano:	14 maja 1999 20:42
> > Do:	Roman Sowa
> > Temat:	3rd Re: ODP: optical pots 2
> > 
> > >         [Roman Sowa]
> > >         Once I had a dream about ring of LEDs, say, 40 around a >
rotary
> > >         encoder showing aproximate value of every parameter. I saw
> > >         something similar in mixing consoles (Neve range)
> > 
> > Do you know those DURACELL batteries which have got an indication >
strip?
> > If you push your tumb and indicator of the strip adjacent to the >
poles
> > of the battery, a chemical reaction starts an colors the strip >
yellow.
> > Well, I thought of an chemical indication like that on the DURACELLs
> > around the knobs to show their position(in software), even if they >
work
> > relativly. The strip must be very cheap, a simple redox reaction. It
> > could be glued to the surface of the sytnhs case.
> > The demands are that the chemicals should work for a long time, the
> > reaction should be quick. 
> > This could be such a great gimmick that there might be even a >
commercial
> > interest in it.
> > 
> > Later,
> > 
> > 
> > Paul van Nugteren
>