A relay is nothing more than an electronic switch. Completing a circuit through a coil in the relay causes a reaction that in turn causes a connection between two or more terminals in the relay. In some relays, breaking the connection to the coil causes a connection between two or more different terminals on the same relay. Technical stuff aside, the following will describe how to use a standard Bosch 4 or 5 pin 12 volt relay to accomplish some things you couldn't do (or couldn't do as easily) without a relay. Here is a basic "Bosch" relay and circuit diagram. These relays are about 1" square, ....... continues at www.ripper1.com/tech/wiring/index.html
	© 2005 Sherwood Lee