I am currently trying to use an output signal from a microcontroller to activate the coils in a high power relay, but the microcontroller output is too weak to switch on the coils. What can i use to get the relay to switch on? Its a arduino microcontroller, and so far using transistors or smaller relays to switch on the larger are all I have in mind., but i dont want to do either. is there some kind of IC that i could use that utilises an external power supply to activate the coils?