hamvil:
I found this:http://uk.rs-online.com/web/p/rele-elettromeccanici/7181862/
Relay,slim,PCB,SPDT,6A,60Vdc coil
Should I use a diode on the control pins with this relay?
Very strange selection. Why must you use a relay with a 60vdc relay coil?
Relays have two independent sets of specification. First the working voltage and current draw for the coil and a second set comprized of the maximum working voltage and current that the contacts can control. Because you are using an arduino to activate or deactivate the relay coil it makes a lot of sense to use a relay coil rated to work with +5vdc as that voltage is avalible from the arduino 5V shield pin. Then you only have to make sure your relay contacts are rated for more then the maximum voltage and current for the circuit they are controlling. If the relay coil requires more then around 30ma (most do) then you will use a npn switching transistor between the arduino output pin and the relay coil.
Lefty