[rescue] LCD monitor diagnosis

wa2egp at att.net wa2egp at att.net
Thu Apr 27 19:06:09 CDT 2006

> For that matter, I've long thought it's time we had cars with ACCURATE
> fuel guages.  And it's easy to do:  Instead of mounting the tank on dumb
> bolts with a float and sender in the tank, chuck the sender and hang the
> tank on four loadcells.  Monitor the output from the load cells, say,
> twice a second.  Average the results, correct for tilt of the vehicle,
> keep a 60-second buffer, and have the guage display a rolling average of
> that 60-second buffer.  If any cell reads differently from the other
> three by more than twice the expected margin or error for, say, twenty
> consecutive readings, drop it from the pool and flag a warning.
> This ought to be able to keep track of how much fuel is in the tank to
> plus or minus a few ounces of fuel, not plus or minus two or three
> gallons (which seems to be the best the current eighty-year-old guage
> technology is capable of).
> As an added bonus, you could even track how much fuel the loadcells say
> you have against how fast the engine computer says you're using it.  If
> the fuel level in the tank is going down faster than you know you're
> using fuel, issue a fuel-leak warning.
> -- 
>  Phil Stracchino                     Landline: 603-886-3518
>  phil.stracchino at speakeasy.net         Mobile: 603-216-7037
>  Renaissance Man, Unix generalist, Perl hacker, Free Stater

I agree but load cells break.  One pot hole and bang, no guage.  Maybe
some optical arrangement, either an array that detects level by the fuel
blocking or reflecting some led light or even measuring light absorption
from one LED.  Would be cheaper which why we have the stupid method
presently used (the damn wires on the rheostat move, messing any attempt
at linearity).


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