some insight please

[spencedog]

I have some clean room that have a push plate and I need to power a 24 volt DC thing on it and I only have 2 wires. is there such a thing that I could power my normally open normally closed relay off this and run my open close signal up the same 2 wires? as far as I have found it would be a 2 wire transmitter and receiver. only problem is that they all do tempature and what not. I just need open close on a c form relay. any ideas??

 

[duke37]

I do not understand what you have. Two wires can be used to send 24V power.

Most relays work on DC so if you put a diode in series with the relay, it will work when the wires are connected one way round but not the other.
Using another relay, with a diode connected the other way round enables the other relay to be energised.
Using AC input will energise both relays.

A flywheel diode will be necessary across each relay.