In project No. 3 we simply connect the 1.5-3 Volt LED Bulb to our Bolt Device What if we want to on off any 20 watt or 10 watt Led Bulb which are used in our house then how to do that
To do that you would have to use a RELAY .
One of the uses of Relay is to control AC Appliances using DC control signal.
I am attaching a circuit showing the connections of the relay, but before implementing it practically, learn more about it because AC is a dangerous thing to play with