Hi there.I'm currently building a project which requires me to switch the mains (230V) input to a 300W (36V 8A, 5V 1A) linear power supply using a relay, controlled by an arduino board. I have an optocoupled 5V electromechanical relay circuit which can be powered by the arduinos 5V supply however i'm not sure if the protection diode will take the back emf generated when the power supply is switched off. Is this suitable if the diode is rated to take the voltage kick back, or does anyone know whether or not I'd have to use a solid state relay for this? I'm fairly new to all this but do understand the physics a bit, any advice on how to work out the back emf would also be greatly valued.
cool, thanks for that. Sorry for sounding ignorant but my head feels a little bit like jelly from reading. I was under that impression but got worried when I read things about the terminals sparking due to the back emf. Is this just a problem with damaging the relay contacts then?Yes or is there any chance a current could be induced in the relay coil (larger than the diodes rating)?No Lefty