Eric,
The regulator doesn't put out a DC level, rather, an on/off pulsing. The
voltage will go to battery voltage for some time, then to zero for another
amount of time. The gauges on our cars averages the pulses to some
voltage. There is also the affect of ambient temperature on the regulator.
It is small, but may be necessary for correct gauge operation.
The regulator runs at a temperature about 125 deg, F. If the regulator is
operated at a temperatur higher than its temperature it will turn the
gauges off. The regulator is just a bi-metal strip. There is a coil of
resistance wire wrapped around the strip. One end of the strip has a
contact on it and the other end is conected to a switched, hot lead.
When the strip is cool,the contacts close, supplying power to the
instruments and the heater. When the strip heats up, it bends away from
the fixed contact, shutting off power to the instruments and the heater.
Once the strip cools down, the cyclew starts all over again.
Making a simple regulator shouldn't be tough, but figuring out how to get
the ambient temperature correction in may be more work than it is worth.
I guess you could put the regulator in an oven while it is operating and
calculate the change in output vs/ temperature. Who knows, it might be
close to the temperature/voltage drop curve of a diode!
The only load that you need to have on is the dash instruments, none of
the others affect the readings.
Peace,
Pat
- Support Habitat for Humanity, A "hand up", not a "hand out" -
Pat Horne, Network Manager, Shop Supervisor/Future planner, CS Dept,
University of Texas, 1 University Station C0500,Austin, Tx. 78712-1188 USA
voice (512)471-9730, fax (512)471-8885, horne@cs.utexas.edu
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