Use the io expander and relay expander with the arduino to control up to 65 280 relays.
Arduino power control relay.
Finally the power outlet box.
Coming to the relay the 5v and gnd pins for the relay module are given from the arduino uno.
In this quick arduino tutorial i will explain how you can control a relay using the arduino board one 1k and one 10k resistors 1 bc547 transistor one 6v or 12v relay one 1n4007 diode and a 12v fan.
First connect neutral wire from the supply to neutral connector on the socket.
When the button is pressed the fan will turn on and will remain in this state until the button is pressed again.
Learn how to use relay with arduino how relay works how to connect relay to arduino how to code for relay how to program arduino step by step.
Circuit diagram and working.
Here to turn on the relay with arduino we just need to make that arduino pin high a0 in our case where relay module is connected.
Without the jumper cap you need to provide an independent power source to power up the relay s electromagnet through the jd vcc pin.
We need to open the box and make connections.
Below given is relay driver circuit to build your own relay module.
In this arduino relay control circuit we have used arduino to control the relay via a bc547 transistor.
That configuration physically isolates the relays from the arduino with the module s built in optocoupler.
Project tutorial by christian.
Control up to 65 280 relays with your arduino.