<VV> Re: Universal Sender Unit

[John Beck]

I'm no electronics wizard Keith.  I was just guessing that since the
universal sender has roughly 3 times the resistance of the original, a 
300% linear amplification of the voltage getting to the gauge should
make things more or less correct.  I've been using 3140 op amps in
another project lately and they seem to be pretty forgiving of my ham
fisted approach to electronics design.  A 3140 and 2 resistors would
make a simple linear amp.  That, plus a filtering capacitor would easily
fit on a tiny circuit board hidden behind the dash.  I think you can get
single 3140's at Radio Shack for about a buck.

Granted, it's not 1960's technology.  IC op amps didn't become common
until the 70's.  I suppose the circuit could be built using 60's vintage
transistors.

Keith Hammett wrote:
> 
> John,
> 
> This sounds interesting.  Do you have any details on this set up.
> 
> I am also looking into maybe using a LM gage put in place of the EM gage.
> Not sure if the LM gage would work with the EM dash.
> 
> I am trying to build a new stainless steel tank for an fc using parts that I
> can get locally a lot cheaper.  A rebuilt fc sender is $125.00 plus
> shipping, the universal is $20.00 (no shipping go past parts house at least
> once a week).
> 
> Any further help on this would be greatly appreciated.
> 
> Keith Hammett
> 
> Date: Tue, 24 Feb 2004 19:30:44 -0600
> From: John Beck <jb30343@navix.net>
> To: virtualvairs@corvair.org
> Subject: Re: <VV> Universal Sender Unit
> That error seems pretty acceptable when compared to some of the factory
> guages I've seen on much newer cars. If accuracy is important, I think
> it would be possible to adapt the 90 ohm sender using an op-amp and a
> few resistors, rather than just a resistor. The parts total for the
> conversion would rise to about a buck. Might be a fun project though.
> --J.B.