I think the term is Rheostat. Please read the following link on the High
power type rheostat.

http://en.wikipedia.org/wiki/Rheostat

Hope it is useful.


"whit3rd"
roups.com...
On Jul 10, 7:05 am, wrote:

I need some help here.
I want to verify a voltage "trip" point on a board that operates on
battery supplied 24vdc.
The maximum draw is about 600MA

The board should change to "recharge required" at 22VDC

It's easy to run an adjustable voltage regulator (LM317) for this
purpose; two fixed resistors and one adjustable resistor, the LM317,
and a small capacitor (probably not required, but it's recommended)
will make a 18-23V regulator. Just power the regulator from the
battery, wiggle the pot 'til it measures 22VDC output, and draw
a red line there. Or do it right, put a 'too low' line at 21.3V and a
'too high' line at 22.6V.

Radio Shack should have all the parts.

The regulator can be inserted between a fully charged battery and
the unit-under-test. It's going to need some heatsinking on the
regulator (get an aluminum box for the project, and bolt the
regulator chip through the convenient hole).