Basic Relay Demo

Relays are carectorized similar to switches. There are SPST, SPDT, DPST like switches. Relay work differently on the inside. Relays contain a coil that when electricity passes through it, a magnetic forces exerts out of the iron in the coil and throws a switch by pulling a lever that pushes or pulls a thin piece of metal that connects two contacts. The relay contacts will be connected or pushed while a current runs through the coil. 

However, ther are latching relays that need current through a different coil to push the contacts back to the original position.

The relay used in this demo is a SPST 12v non-latching relay I got at Tayda Electronics. I did experiment with DPDT relay since it fit better in the breadboard but had better luck with the SPST. I read the datasheet on this relay to determine the poles and the switch. It was different than I thought initially so it is always important to read the datasheet.