Voltage Relays

Hello, I'm new to this board, and well, making things in general, and am particularly stumped about voltage relays. I know in theory how they work, a small voltage triggers a circuit to close and let a larger voltage through, but practically have no idea what the terminology used in the data sheets mean. What I'm looking for is to have 120VAC be triggered by a 5VDC. The 120VAC would only be on as long as there was 5VDC triggering it. Can anyone out there tell me what I should be looking for, in particular, what the voltage that causes the circuit to close is called? Thanks. --D.K.

gmoon9 years ago
... in particular, what the voltage that causes the circuit to close is called?

Coil voltage (and it's friend, coil current) is likely what you're describing.
NachoMahma9 years ago
. Interposing relay is a good place to start.
. When spec'ing the power contacts, you need to look at both voltage and current. The contacts need to be able to break the circuit under full load.
. You need a 5VDC relay coil (will probably need a clamping diode) with contacts rated for at least 120VAC (I'd go with at least 250V, just to be on the safe side) and whatever current your load will draw.