Use the io expander and relay expander with the arduino to control up to 65 280 relays.
Arduino power control relay.
We need to open the box and make connections.
The control pin for the relay is connected to the pin 8 of arduino.
Coming to the relay the 5v and gnd pins for the relay module are given from the arduino uno.
Control up to 65 280 relays with your arduino.
That configuration physically isolates the relays from the arduino with the module s built in optocoupler.
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.
Below given is relay driver circuit to build your own relay module.
Without the jumper cap you need to provide an independent power source to power up the relay s electromagnet through the jd vcc pin.
Circuit diagram and working.
Project tutorial by christian.
Finally the power outlet box.
In this arduino relay control circuit we have used arduino to control the relay via a bc547 transistor.
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.
The connections between the relay module and the arduino are really simple.
When the button is pressed the fan will turn on and will remain in this state until the button is pressed again.