Arduino Transistor Relay Circuit

Arduino board jumper wires breadboard.

Arduino transistor relay circuit.

We have connected transistor base to arduino pin a0 through a 1k resistor. In this arduino relay control circuit we have used arduino to control the relay via a bc547 transistor. The second leg connected to analog in 0 of the arduino. First leg of the potentiometer is connected to 5 volts.

Schematic view of a potentiometer and transistor connected to an arduino. Usually an npn transistor in a common emitter configuration used as a switch drives the relay. 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.

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. The base of the transistor is connected to digital pin 9 of the arduino through a 1 kilohm resistor. An ac bulb is used for demonstration.

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. 2 x 220ω resistors. The transistor in this example completes the motor s circuit to ground.

The arduino can only provide 40ma at 5v on its digital pins. 1 x tip120 darlington transistor is recommended but any one that will handle your relay will work. The parts you will need. The third leg is connected to ground.

Here is a simple circuit that uses a bipolar junction transistor bjt to drive a small 5 v relay coil. The picture above shows the circuit you need to build. 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. Most motors require more current and or voltage to operate.

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. 1 x sharp pc817 optocoupler. A transistor can act as a digital switch enabling the arduino to control loads with higher electrical requirements. 1 x 1n4001 diode.