Air Core instrument Help

I have a bunch of air core (coil) operated instruments like egt, hyd press, etc that I bought off eBay. I would like to include them in my simulator as I have found applying a small voltage to some of the output pins makes the gauge 'work' and by varying the voltage you can have the needle positioned where ever you want.

My first question is this...can you damage these gauges by applying direct current voltage to them? (without exceeding the needle maximum value on the gauge...in other words avoiding applying too my dc current that makes the needle 'peg')

My idea is to have some of the gauges indicate a quantity value...say hydraulic quantity...that way when the power is 'off' the gauge will read '0' and when power is applied (through a pot) i can have the gauge indicate a specified value of quantity

Thanks in advance!

Hello, I bought an air-coil RMI surplus and was able to get it working. The interface I built is a PC driving a PIC micro that in turn
sends a digital sine value and digital cosine value to 2 DACs. The output of the DACs drive an op Amp and then a standard audio
amp. Each audio amp is connected to one of the 2 air-coil coils. This allows the value and polarity of the DC voltage to drive
the indicator. If you don't exceed the needle pinning you should be all right. Hope this helps somewhat. If you need schematic
I can send ... regards.