B sc engineer in electrical and electronic engineering.
Arduino relay transistor diode.
The design of the circuit is described here.
Arduino board jumper wires breadboard.
2 x 220ω resistors.
Transistor acts as a switch to control the 12v to relay coil.
Arduino tricks is the online education platform which teaches students every day that too completely free of cost.
Therefore we need a device to amplify the current.
Therefore we need a device to amplify the current.
The following arduino program completes the post.
Connections to the household appliance are not shown.
1 x sharp pc817 optocoupler.
In this project the npn transistor 2n2222 drives the relay when the npn junction gets saturated.
1 x tip120 darlington transistor is recommended but any one that will handle your relay will work.
In this arduino relay control circuit we have used arduino to control the relay via a bc547 transistor.
Below given is relay driver circuit to build your own relay module.
The picture above shows the circuit you need to build.
1 x 1n4001 diode.
Circuit diagram and working.
In this project the npn transistor 2n2222 drives the relay when the npn junction gets saturated.
The base terminal of the 2n2222 transistor is connected to any of the digital i o pin of the arduino through a 1kω current limiting diode in this project base is connected to pin 7 of arduino.
The project is used to demonstrate the high voltage driving capabilities of a relay using arduino uno.
Just a simple circuit that contains our transistor diode resistor and of course the relay.
Diode acts as a protection for transistor against back emf induced through relay coil during transit conditions.
The coil of the relay needs a large current around 150ma to drive the relay which an arduino cannot provide.
The parts you will need.
We have connected transistor base to arduino pin a0 through a 1k resistor.
Resistor adjusts input current from arduino to the transistor.
The coil of the relay needs a large current around 150ma to drive the relay which an arduino cannot provide.