Thread: Relays, Relays, Relays ?????

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Basically, i just don't get what a relay actually is, i see people talking about them alot on the forum and i feel that i'm missing out on somthing that would be useful to know. I have seen other threads which ask similar questions, but its all to complicated for me. Please could someone give me a basic explanation of relays and there uses. Thanks You.

A relay has a coil in it that when trigered, usualy with lo voltage turns on something of a different voltage.

Relays are electrically-controlled switches. Instead of your finger pressing a button, a small electromagnetic coil pulls a strip of metal to make a contact and complete a circuit between two or more terminals in the relay. When power is applied to the coil, the relay is considered to be energized. When the coil is on, power can flow through the terminals, when it is off the power is interrupted.
The uses are many. Most are for using safe, low-voltage power to switch on a higher voltage/current device. One example is a doorbell button. The power at the button is usually 12-24 volts DC, and the actual bell-ringing device is 110 volts AC. When you press the button, the DC power turns on a relay that, in turn, controls the AC power going to the bell.

A relay is an electronic device that activates a switch using a electromagnet. For most of the uses around here, it is a low, relatively safe voltage like 12v DC that would be activated using a mat switch or such. This 12v switch would energize a electromagnet that would activate a switch for higher voltage items like lights and such. You wouldn't want 110v AC running through a mat switch that your TOTs step on!!

Otaku- your description makes more sense than mine

Thanks guys, so a relay is a switch. Do you possibly know why somone would use a relay in a prop. ?

so, say you want to turn on a light on cue. Your controller board only outputs, for example, 6 volts at most. The light needs 120 volts. So, you connect the light to a relay and connect the relay to your controller board. When you give the relay the 6v, it completes the light bulb's power circuit, allowing it to turn on.

It's basically a low voltage powered on/off switch.

Ahhhhh right ok, sorry for all the questions but would there be a tutorial anywhere for wiring up relays and also when looking to buy a relay is there anything specific i should look for other than just a relay (such as a type of relay). ?

You can look on youtube under how to wire a relay and get a good number of different videos to show you how to wire them up. As far as what to look for, the main thing is your coil voltage rateing. if you go to an auto parts store you can fond relays there that have a 12v coil, more than likely that is what you will want to use.

Thanks soooo much! for the great and quick responces guys, I feel like i know relays back to front now