Last week in How to Electronically Modify Your Car, Part 6 we
looked at a special way in which pots can be used to alter the
output of sensors used in electronic car systems. It’s a very
tricky technique that allows you to achieve lots of effective
outcomes at nearly zero cost. This week we’re also looking at
simple and cheap electronic components that are again often
overlooked as ways of achieving excellent car modifications –
relays. What’s a Relay? A relay is just a small switch whose
movement is caused by the action of an electromagnet inside the
box. When power is applied to the relay’s coil, the
electromagnet comes alive and pulls across the The simplest
relay is a single pole, single throw (SPST) design. This
designation refers to the switching part of the relay where when
it's activated, one wire (a "single pole") can be connected only
one way (a "single throw"). Just like an on/off switch, when you
power up the relay's coil, the connection is made; when you un-
power the coil, the connection is broke