Arduino Transistor Relay Circuit

Thats it our circuit is complete now we can upload the code to the arduino to turn on or off the relay.

Arduino transistor relay circuit.

The arduino can only provide 40ma at 5v on its digital pins. 2 x 220ω resistors. 1 x sharp pc817 optocoupler. This video npn transistor based 12v dc relay control drive simple make it this type transistor is a semiconductor device used to switch electronic signals a.

The optocoupler is the most important part it isolates the circuit from the relay using. Circuit diagram and working. Basically when 5v flow through the 1k resistor to the base of transistor a current of about 0005 amps 500 microamps flows and turns on the transistor. We have connected transistor base to arduino pin a0 through a 1k resistor.

Here is a simple circuit that uses a bipolar junction transistor bjt to drive a small 5 v relay coil. So whenever i turn the arduino the first relay is on and its on for 3 seconds and after that it goes off and the second relay is on 3 sec similarly for third and fourth and after fourth all will be off for 3 seconds and after that all four legs will be turned on. The transistor in this example completes the motor s circuit to ground. Basically when 5v flow through the 1k resistor to the base of transistor a current of about 0005 amps 500 microamps flows and turns on the transistor.

I just programmed the arduino and attach with my homemade relay circuit board and connect all four appliances with the relay board. 1 x tip120 darlington transistor is recommended but any one that will handle your relay will work. First leg of the potentiometer is connected to 5 volts. An ac bulb is used for demonstration.

Schematic view of a potentiometer and transistor connected to an arduino. 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. The parts you will need.

Below given is relay driver circuit to build your own relay module. Thats it our circuit is complete now we can upload the code to the arduino to turn on or off the relay. 1 x 1n4001 diode. Arduino board jumper wires breadboard.

Most motors require more current and or voltage to operate. The second leg connected to analog in 0 of the arduino. Usually an npn transistor in a common emitter configuration used as a switch drives the relay. A transistor can act as a digital switch enabling the arduino to control loads with higher electrical requirements.