I have a temperature control circuit that runs at 12 V, but I need to control a 120V circuit (1/2 amp is enough)
2006-12-12 07:45:53 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Engineering
Try the following link for Radio Shack. Look for a 12 VDC/125VAC relay. It means you can safely put 12 VDC directly to the coil of the relay and switch a 125 VAC load. For your application you will need at least a Single Pole Double Throw (SPDT) relay. That means it will switch one circuit and has a normally open and a normally closed contact.
One other note, it is best to have a diode in parallel with the relay coil to handle the voltage spike that would normally occur when the relay turns off. It doesn't have to be a big fancy diode. Place it so it does not allow current to flow under normal circumstances (in other words, its not shorting out your relay).
2006-12-12 09:45:13 · answer #1 · answered by Anonymous · 0⤊ 0⤋
find any relay or contactor rated at 120V with a 12 v coil. both ac?? make sure as dc will burn out an ac coil
2006-12-13 08:18:51 · answer #2 · answered by Mark G 2 · 0⤊ 0⤋
You should be able to find what you need at Kele and Associates. They have relays that have polyvolt coils to handle multiple voltages. They can also handle either DC or AC voltage.
www.kele.com
2006-12-12 09:51:27 · answer #3 · answered by ? 3 · 0⤊ 0⤋
Radio Shack
Grainger.com
McMaster Carr
Just size the contact rating you need. You can parallel the contact wiring on a DPDT relay
2006-12-12 08:45:44 · answer #4 · answered by MarkG 7 · 1⤊ 0⤋