How to Use 1-kanaals 3V relais module: Examples, Pinouts, and Specs

The 1-kanaals 3V relais module by Kiwi is a single-channel relay module designed to operate at a low voltage of 3V. This module is ideal for controlling high-voltage devices using low-voltage signals, making it a versatile component in automation and control systems. It acts as an electrically operated switch, allowing microcontrollers or other low-power devices to safely control high-power circuits.

• Home automation systems (e.g., controlling lights, fans, or appliances)
• Industrial control systems
• Robotics and IoT projects
• Motor and pump control
• Signal isolation between low-power and high-power circuits

The following table outlines the key technical details of the 1-kanaals 3V relais module:

The module has a total of 6 pins and terminals, as described below:

1. Power the Module: Connect the VCC pin to a 3V DC power supply and the GND pin to the ground.
2. Control Signal: Connect the IN pin to a microcontroller (e.g., Arduino UNO) or any other control circuit. A HIGH signal (3V) will activate the relay, while a LOW signal (0V) will deactivate it.
3. Connect the Load:
   • For devices that should be OFF by default, connect the load between the COM and NO terminals.
   • For devices that should be ON by default, connect the load between the COM and NC terminals.
4. Isolation: Ensure proper isolation between the low-voltage control side and the high-voltage load side to prevent damage or hazards.

• Current Ratings: Ensure the load does not exceed the relay's maximum current rating of 10A.
• Flyback Diode: If controlling an inductive load (e.g., motors), use a flyback diode across the load to protect the relay from voltage spikes.
• Safety: Always handle high-voltage connections with care. Disconnect power before making any changes to the circuit.
• Signal Stability: Use a pull-down resistor on the IN pin to prevent false triggering due to noise.

Below is an example of how to control the relay module using an Arduino UNO:

• Connect the VCC pin of the relay module to the 3.3V pin of the Arduino.
• Connect the GND pin of the relay module to the GND pin of the Arduino.
• Connect the IN pin of the relay module to digital pin 7 of the Arduino.
• Connect a load (e.g., a light bulb) between the COM and NO terminals of the relay.

// Define the relay control pin
const int relayPin = 7;

void setup() {
  // Set the relay pin as an output
  pinMode(relayPin, OUTPUT);
  
  // Ensure the relay is off at startup
  digitalWrite(relayPin, LOW);
}

void loop() {
  // Turn the relay ON
  digitalWrite(relayPin, HIGH);
  delay(5000); // Keep the relay ON for 5 seconds
  
  // Turn the relay OFF
  digitalWrite(relayPin, LOW);
  delay(5000); // Keep the relay OFF for 5 seconds
}

1. Relay Not Activating:

   • Cause: Insufficient voltage or current to the VCC pin.
   • Solution: Ensure the power supply provides a stable 3V DC and sufficient current.

2. False Triggering:

   • Cause: Electrical noise or floating IN pin.
   • Solution: Use a pull-down resistor (e.g., 10kΩ) on the IN pin to stabilize the signal.

3. Load Not Switching:

   • Cause: Incorrect wiring of the load to the relay terminals.
   • Solution: Double-check the connections to the COM, NO, and NC terminals.

4. Overheating:

   • Cause: Load exceeds the relay's maximum current rating.
   • Solution: Use a load within the specified 10A limit or use a higher-rated relay.

Q1: Can I use this relay module with a 5V microcontroller?
A1: Yes, but you will need a level shifter or resistor divider to step down the control signal to 3V.

Q2: Is the relay module safe for switching AC loads?
A2: Yes, it can handle up to 250V AC, but ensure proper insulation and safety precautions.

Q3: Can I control multiple relays with one microcontroller?
A3: Yes, as long as each relay has its own control pin and the microcontroller can supply sufficient current.

Q4: What is the purpose of the optocoupler?
A4: The optocoupler provides electrical isolation between the low-voltage control circuit and the high-voltage load circuit, enhancing safety.