How do you figure out the minimum voltage / current is required to operate an EM coil? For Example I have some Bally score reels with CD-29-1600 Coils (Solenoids).

I know they typically run off of AC(28VAC?), but I have read they can work off of DC as well. DC power supplies are much more common than AC, so I would really like to know the DC voltage minimum. Reading around pinside, DC seems to be recommended at 24VDC. But could 20VDC be enough, 12VDC?

I ask because I can't seem to find any sort of data sheet on the coils.

Thank you for the link, and it has some great info. However, it does not seem to touch on DC voltage for coils. Only thing I did find was "higher the voltage applied" the stronger the action.

So in that sense it seems like voltage could be so low that there is not enough power to pull in the coil plunger. That minimum voltage is what I am trying to find.

Does anyone know what this is or have documentation on a voltage curve or something? Or is it basically go buy a variable power supply then guess and check?

So then one last stupid question. Is there any resource that has the recommended ("default") voltage by coil/solenoid type. Like you could type in the coil part number, and have its info show up?

Or is the best bet to find this to grab the schematics for a machine and see what voltage is supplied to the coil?