power for dash gauges?

[N8N]

Some of you may recall that I inherited this guy from a previous employer when they cleaned out the warehouse in preparation for a move:

http://members.cox.net/njnagel/image...2382_small.JPG

I finally determined exactly what it is (a test set for locating wiring faults, and also a general Wheatstone bridge/galvanometer type thing) and amazingly have located someone who's scanned the instruction card and booklet. So if I can manage a few minor repairs to it, it should be functional again.

I've found that it can also be used as a resistance box, but the resistors that make up the variable resistance section, while physically large, are only rated at 1/2W. Is that enough to test fuel and temp gauges on the bench, or is that asking for trouble? I do have a 12V power supply...

nate

[ddub]

Boy, I sure don't know what that thing is, but it really looks cool!

[Bud]

I haven't seen one of those things since I went to school for avionics back in the 60's. I use a big rheostat rated at 200 ohms in series with the sender terminal hooked to my 12 volt bench supply. I found that the 12 volt SW gauges will go to high reading at about 75 ohms on the rheostat and somewher around 150 on the low side. The half watt resistors in your Wheatstone bridge will go up in smoke if you try to use it to test those old gauges as they draw more current than the resistors will tolerate. Bud