Message text written by "M Brooks"
>Hi all,
Well I got the IC 10v Voltage Regulators I had ordered and decided to
perform a little test to see if ambient temperature did make a large
difference in gauge readings requiring a correction.
Here's the setup:
I hooked the 10V regulator to a 12V powersupply and then attached the
regulated 10V supply to a 500 ohm variable resistor. The output of the
resistor was hooked to a Fuel Gauge I had lying around and the other side
of
the gauge was hooked to the negative side of the power supply.
After a little fiddling with the resistor I got the gauge to read 1/2 at
room temperature, which in Florida is about 78 degrees F.
Then I moved the whole apparatus to the kitchen and stuck the gauge in the
freezer for 20 minutes - which for argument sake is at 30 degrees F.
The indicator does, of course, read less full BUT only by the slightest
amount! About 1/16" lower than at room temperature. This is with a
difference in ambient temperature of about 58 degrees. I think that is
quite
an acceptable margin for error.
I did find, however, that when I used a hair dryer set on cold, blown at
the
gauge it became very inaccurate and read nearly empty. I'm sure this is
because the movement of the air was removing heat from the gauge's coil. Of
course this is not really AMBIENT temperature and I'm sure that even with
the top down at 70 MPH the amount of wind behind the instrument panel is
negligible ;-)
More to come...
~Mike Brooks
<
That's what I like : good, objective experimentation. Keep up the good
work.
Thanks for sharing the results.
Dave Massey
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