1 Channel 5V Relay Module

A 1-Channel 5V Relay Module is an electronic switching device that allows a low-power microcontroller (like an Arduino, Raspberry Pi, ESP32, etc.) to safely control high-voltage or high-current appliances, such as lights, fans, motors, and pumps. It acts as an electrically operated switch, using a 5V signal to open or close the circuit connected to a higher voltage source (like 220V AC or 12V DC).

 

Technical Specifications:

• Operating Voltage: 5V DC
  
• Trigger Voltage: 0–2V LOW (active low) to activate the relay
  
• Control Signal Voltage: 0–5V (compatible with 3.3V and 5V logic)
  
• Relay Type: Electromechanical relay (typically SRD-05VDC-SR-C)
  
• Number of channels: 1

Pinouts:

Connection with Arduino:

Module	Arduino UNO
VCC	5V
GND	GND
IN	Pin 7

 

Relay Output terminal(Screw terminals)

Terminal Label	Description
COM	Common terminal (connects to Power or load)
NO	Normally Open (Connected to COM when relay is activated)
NC	Normally Closed (Connected to COM when relay is Inactive)

Sample code:

const int relayPin = 7;

void setup() {
  // Set the relay pin as OUTPUT
  pinMode(relayPin, OUTPUT);
}

void loop() {
  // Turn the relay ON (active LOW)
  digitalWrite(relayPin, LOW);
  delay(1000); // wait 1 second

  // Turn the relay OFF
  digitalWrite(relayPin, HIGH);
  delay(1000); // wait 1 second
}