In this section, we will learn the concept of separating a DC circuit from an AC circuit by using a relay device. AC powered devices operate at dangerous voltages and currents, whereas the Arduino Uno is a 5V, low current device in comparison to an AC powered device. Therefore, in order to interface the Arduino with an AC powered device, an intermediate device known as a relay is used. A typical relay device is shown in the following figure:
Figure 1:&# A typical relay device
As we can see, there are three socket type ports on the left-hand side of the Relay device. Usually, these ports are marked with abbreviations such as: NO, C, and NC. The usage of these three sockets is explained as follows:
- Normally Open (NO): This port is called 'Normally Open' because this port is always disconnected (Open) from the AC circuit, via the...
