3-Channel Relay Module 3.3V 5V with Optocoupler for PIC AVR DSP ARM

Description

What it is

The 3-channel relay module with optocoupler is an electronic component used to control electrical loads from logic circuits such as Arduino, PIC, or AVR. The module allows managing external electrical devices through low-voltage signals.

Features

• Number of channels: 3
• Supported power supply voltages: 3.3V – 5V
• Integrated optocoupler for electronic isolation

What it is for

Relay modules are ideal for home or industrial automation projects. For example, they can be used to control lighting systems based on data from external light sensors. Additionally, it is compatible with microcontrollers like Arduino, ESP32, and others.

Tutorial: How to use 3-Channel Relay Module

The 3-channel relay module is ideal for controlling electrical devices from a logic circuit, such as Arduino. It is suitable for both beginners and experts looking to integrate relay control into electronic projects.

What you need

• Arduino or microcontroller
• Jumper Wire M/F
• Connection to the device to be controlled

Steps

1. Connect the VCC and GND pins of the relay module to the 5V and GND pins of Arduino.
2. Identify the IN1, IN2, IN3 pins on the relay module that correspond to the channels to be controlled.
3. Connect jumper wires from the IN pins to the microcontroller for logic control.
4. Check the voltage of the external device (AC or DC) and connect it to the appropriate relay terminals COM and NO/NC.
5. Write an Arduino sketch that sets the IN pins high/low as desired.

Example code

void setup() {
  pinMode(2, OUTPUT);
pinMode(3, OUTPUT);
pinMode(4, OUTPUT);
}

void loop() {
digitalWrite(2, HIGH); // Attiva il relè del canale 1
delay(500);
digitalWrite(2, LOW);
delay(500);
}

Mini project

Create an intelligent lighting system that turns external lights on or off based on data from light sensors.

Common mistakes

• Do not check the device voltage before installation.
• Incorrect pin IN connection to COM/NO/NC terminals.
• Omission of pull-up/pull-down resistor on logic pins.
• Accidental disconnection during use.

Recommended accessories

• Electronic protection module
• Light sensors
• 1-channel relay for smaller projects
• M/F Jumper Wire

Frequently asked questions

How can I control multiple relays from a single microcontroller?
Use a multiplexer or add more relay modules.

What is the difference between NO and NC terminals on the relay?
NO (Normally Open) connects the circuit when the relay is active, NC (Normally Closed) disconnects it.