How to Use K30: Examples, Pinouts, and Specs

The K30 is a versatile relay designed for controlling high-power loads using low-power signals. Its compact design and reliable switching capabilities make it an essential component in a wide range of electronic circuits. The K30 relay is commonly used in applications such as home automation, industrial control systems, motor control, and power distribution. Its ability to isolate the control circuit from the load circuit ensures safety and efficiency in operation.

The K30 relay is designed to handle various electrical loads while maintaining reliable performance. Below are its key technical specifications:

• Type: Electromechanical Relay
• Coil Voltage: 5V, 12V, or 24V DC (depending on the variant)
• Contact Rating: 10A at 250V AC or 10A at 30V DC
• Contact Configuration: SPDT (Single Pole Double Throw)
• Coil Resistance: Varies by voltage (e.g., 70Ω for 5V variant)
• Switching Time: Typically 10ms (operate) and 5ms (release)
• Dielectric Strength: 1500V AC (between coil and contacts)
• Insulation Resistance: ≥100MΩ at 500V DC
• Operating Temperature: -40°C to +85°C
• Dimensions: Compact form factor (e.g., 28mm x 12mm x 15mm)

The K30 relay typically has 5 pins, which are configured as follows:

1. Power the Coil: Connect the coil terminals (pins 1 and 2) to a DC power source or control signal. Ensure the voltage matches the relay's rated coil voltage (e.g., 5V, 12V, or 24V).
2. Connect the Load:
   • Attach the load's power source to the Common (COM) terminal (pin 3).
   • Connect the load to either the Normally Open (NO) terminal (pin 4) or the Normally Closed (NC) terminal (pin 5), depending on the desired behavior:
     • Use the NO terminal if the load should be powered only when the relay is activated.
     • Use the NC terminal if the load should be powered when the relay is inactive.
3. Control the Relay: Apply a control signal to the coil terminals to activate or deactivate the relay. This will switch the load circuit between the NO and NC terminals.

• Diode Protection: Always connect a flyback diode across the coil terminals to protect the circuit from voltage spikes caused by the relay's inductive load.
• Current Ratings: Ensure the load current does not exceed the relay's contact rating (10A).
• Isolation: Use optocouplers or transistors to isolate the control circuit from the relay if necessary.
• Mounting: Secure the relay in a socket or PCB to prevent mechanical stress.

Below is an example of how to control the K30 relay using an Arduino UNO:

// Define the pin connected to the relay's coil
const int relayPin = 7;

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

void loop() {
  // Activate the relay (turn on the load)
  digitalWrite(relayPin, HIGH);
  delay(1000); // Keep the relay on for 1 second

  // Deactivate the relay (turn off the load)
  digitalWrite(relayPin, LOW);
  delay(1000); // Keep the relay off for 1 second
}

Note: Ensure the relay's coil voltage matches the Arduino's output voltage (typically 5V). Use a transistor if the relay requires higher current than the Arduino can supply.

1. Relay Not Activating:

   • Cause: Insufficient coil voltage or current.
   • Solution: Verify the power supply voltage and current match the relay's specifications.

2. Load Not Switching:

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

3. Voltage Spikes Damaging Components:

   • Cause: Lack of a flyback diode across the coil.
   • Solution: Install a diode (e.g., 1N4007) across the coil terminals, with the cathode connected to the positive terminal.

4. Relay Buzzing or Chattering:

   • Cause: Unstable control signal or insufficient power supply.
   • Solution: Use a stable power source and ensure the control signal is steady.

• Q: Can the K30 relay handle AC loads?
  A: Yes, the K30 relay can handle AC loads up to 250V, provided the current does not exceed 10A.

• Q: Is the K30 relay suitable for switching high-frequency signals?
  A: No, the K30 relay is not designed for high-frequency switching. Use a solid-state relay for such applications.

• Q: Can I use the K30 relay with a 3.3V microcontroller?
  A: Yes, but you may need a transistor or relay driver circuit to provide sufficient voltage and current to the relay coil.

By following this documentation, you can effectively integrate the K30 relay into your electronic projects and ensure reliable operation.