A relay basically allows a relatively low voltage to easily control higher power circuits.
Arduino transistor relay control.
First leg of the potentiometer is connected to 5 volts.
Arduino board jumper wires breadboard.
1 x 1n4001 diode.
Circuit diagram and working.
The detail instruction code wiring diagram video tutorial line by line code explanation are provided to help you quickly get started with arduino.
1 x tip120 darlington transistor is recommended but any one that will handle your relay will work.
The second leg connected to analog in 0 of the arduino.
The arduino can only provide 40ma at 5v on its digital pins.
The basic transistor switching with arduino for arduino digital 7th pin is output if the arduino send logic 1 high the mini cooling fan turns on.
1 x sharp pc817 optocoupler.
The optocoupler is the most important part it isolates the circuit from the relay using.
Below given is relay driver circuit to build your own relay module.
The following circuit shows how to control a relay with your arduino or esp8266 microcontroller.
The third leg is connected to ground.
Therefore we use the 5v supply voltage for the coil and use a npn transistor to turn on and off the low power electrical circuit.
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.
In this arduino relay control circuit we have used arduino to control the relay via a bc547 transistor.
The parts you will need.
The picture above shows the circuit you need to build.
The base of the transistor is connected to digital pin 9 of the arduino through a 1 kilohm resistor.
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.
The npn transistor is controlled by a digital i o pin of the arduino microcontroller.
An ac bulb is used for demonstration.
Schematic view of a potentiometer and transistor connected to an arduino.
You can use a 5v relay to switch the 120 240v current and use the arduino to control the relay.
We have connected transistor base to arduino pin a0 through a 1k resistor.
If the transistor base terminal is 0 low then fan turns off for delay and other you can set with help of arduino ide and arduino uno.