
In this article we will talk about relays.
The relay is a device that permits with a small voltage to pilot a reed switch.
How this device should be applied on the circuit ?
How can we place it on an arduino ?
All these answers will be cleared in a while.
Let's start with some theory to see what happens in detail.
At the top of the relay we can see the 5V as input pilot voltage.
And we can see the 10A limitation at the 250VAC of the reed switch.
So with a 5 Voltage we can "switch" a 250VAC device that can consume up to 10A (P=V*I=2,5KW).
If you need to pilot a device that consumes more you should use a "bigger" relay that fit at your needs.