This tutorial explains following concept, Transistor Switching, Working of Relay, Switching with relay on Arduino, Motor control on Arduino using Relay.
1. Introduction:
This tutorial explains following things-
- Switching with NPN transistor.
- Working and concept of Relay
- Switching by relay.
- Relay and Arduino
- Motor control by Relay on Arduino
1.2 Switching by NPN Transistor.
make the following circuit. When you give High signal on Input it connects the LED to GND. Here we are taking HIGH input by push button switch.
1.3 Relay:
Following Video of Robo India explains working and concept of relay-
1.3 46ND006-P:
This is the relay we are going to use. This relay has got two poles, means there are two switches but both are trigged by a single Coil thus they operate simultaneously. Following Diagram will give you better understanding about the relay we are using.
2. Required Hardware
Following Hardware will be required to perform the example of this tutorials.
3. Building Circuit – 1 (Understanding of Relay)
This circuit is to make you understand the concept of relay. Our relay has got two poles, thus we have connected 4 LED to this. Two at Normally Connected pins and two are normally open pins. One status LED is also there. The Status LED tells that Relay is on of Off. If Status LED is on it means that relay is on (Common is connected to NC.) and vice versa.
Red LED- Statuts LED of Relay
Yellow LED – Connected to NC terminal of Relay
Green LED – Connected to NO terminal of Relay
Conclusion we can draw –
If red is off – means relay is off – means – Common terminals of Relay are connected to NC – Thus Yellow LEDs are ON.
If red is ON – means relay is ON – means – Common terminals of Relay are connected to NO – Thus Green LEDs are ON.
Video will help you to understand.
3.1 You may go with Robo India’s R-Board(UNO Compatible)-
here is the schematic:
or
3.2 You may go with original Arduino UNO Board-
here is the schematic:
4. Programming:
We don’t need any special programming to operate Relay of Transistor, Simple Digital output programming is required. So the programme we have added here is as same as in our other tutorial of Digital Output – LED Blinking. The same codding is used throughout the tutorial.
You may download code (Arduino Sketch) from here.
// Digital output tutorial by ROBO INDIA
// www.roboindia.com
// Digital output is taken on a LED that remains ON for one second and
// OFF for another.
// Defining Pin 2 as LED.
const int LED = 2; // from the circuit we can see that we have connected LED on Pin 2
void setup() {
pinMode(LED, OUTPUT); // Defining LED pin as OUTPUT Pin.
}
// Below mentioned code runs for ever(infinite loop)
void loop() {
digitalWrite(LED, HIGH); // LED gets turned ON (1/HIGH/+5V)
delay(1000); // Waiting for one second.
digitalWrite(LED, LOW); // LED gets OFF (0/LOW/0V/GND)
delay(1000); // here and above Delay is in mili second (1000 = 1 second)
}
5. Circuit -2 (Motor control on Arduino using Relay):
As we have mentioned earlier that the codding is same for the entire tutorial. Here we are controlling one DC motor on Arduino board. Motor consumes more power than the other circuit thus you will need separate Power supply to run a motor. It will not run on Laptop/PC’s USB.
The circuit you will need is here –
5.1. You may go with Robo India R-Board (Arduino UNO based)-
here is the schematic of above circuit:
5.2. or You may go with orginal Arduino Board –
here is the schematic of above circuit:
7. output:
Here is the output of this tutorial. Above code is implemented on Robo India R-Board and Arduino UNO Both.
If you have any query please write us at info@roboindia.com
Thanks and Regards
Content Development Team
Robo India
http://roboindia.com