Arduino Relay Transistor Diode

The coil of the relay needs a large current around 150ma to drive the relay which an arduino cannot provide.

Arduino relay transistor diode.

The design of the circuit is described here. An ac bulb is used for demonstration. Resistor adjusts input current from arduino to the transistor. 1 x 1n4001 diode.

B sc engineer in electrical and electronic engineering. 2 x 220ω resistors. Just a simple circuit that contains our transistor diode resistor and of course the relay. In this project the npn transistor 2n2222 drives the relay when the npn junction gets saturated.

The following arduino program completes the post. Arduino tricks is the online education platform which teaches students every day that too completely free of cost. Circuit diagram and working. The following picture depicts how to connect the different parts using a solderless breadboard jumper wires a transistor a diode a relay a push button and two 10k resistors.

Diode acts as a protection for transistor against back emf induced through relay coil during transit conditions. 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. 1 x tip120 darlington transistor is recommended but any one that will handle your relay will work. Connections to the household appliance are not shown.

In this arduino relay control circuit we have used arduino to control the relay via a bc547 transistor. The picture above shows the circuit you need to build. Therefore we need a device to amplify the current. Arduino board jumper wires breadboard.

Therefore we need a device to amplify the current. The optocoupler is the most important part it isolates the circuit from the relay using. We have connected transistor base to arduino pin a0 through a 1k resistor. Below given is relay driver circuit to build your own relay module.

In this project the npn transistor 2n2222 drives the relay when the npn junction gets saturated. The project is used to demonstrate the high voltage driving capabilities of a relay using arduino uno. The parts you will need.