Hmm ok, so after reading all your comments and discussing this at the university i think the most logical way to proceed would be to feed the signal with the arduino to a wall charger which is hooked up to the electromagnets. This way, the charger is activated only when necessary and it would have enough power. But I am wondering, if half the magnets need to be permanently active and half need to be pulsating, how do i wire this? do I plug the arduino in between the charger and magnets like some sort of switch? or would i need two different chargers?