I have a project where I need an A-B selector to send a momentary contact to a device. I have a relay to short the device, but how do I get just a pulse of power from the switch to the solinoid coil? Can I use a 555 timer IC?
You didn't mention what is the a-b selector and the device.
If your meaning is press the switch or input signal, and active the relay, then you can use ne555 monostable, you can search on this web or google for more info.