How to Use UV-C LED: Examples, Pinouts, and Specs

A UV-C LED is a light-emitting diode that produces ultraviolet light in the C spectrum (UV-C). This type of UV light, with wavelengths ranging from 100 to 280 nanometers, is known for its germicidal properties, making it highly effective for disinfection and sterilization applications. UV-C LEDs are used in a variety of settings, including water purification, surface disinfection, and air sanitization.

1. Power Supply: Ensure that the power supply matches the forward voltage and current requirements of the UV-C LED. Overdriving the LED can result in overheating and reduced lifespan.

2. Current Limiting: Always use a current-limiting resistor or a constant current driver to prevent damage to the LED. The value of the resistor can be calculated using Ohm's law: R = (V_supply - Vf) / If.

3. Heat Management: UV-C LEDs can generate significant heat. It is crucial to provide adequate heat sinking to maintain the LED's performance and longevity.

4. Safety Precautions: UV-C light can be harmful to eyes and skin. Always use appropriate shielding and never look directly at the UV-C LED when it is powered on.

• Use the UV-C LED in well-ventilated areas to avoid the buildup of ozone, which can be produced by UV-C light.
• Ensure that the LED is mounted securely and that the electrical connections are stable.
• Test the circuit without the UV-C LED first to confirm that the voltage and current are within the specified range.

// Define the UV-C LED control pin
const int uvLedPin = 9; // Connect UV-C LED to pin 9 with appropriate resistor

void setup() {
  pinMode(uvLedPin, OUTPUT); // Set the UV-C LED pin as an output
}

void loop() {
  digitalWrite(uvLedPin, HIGH); // Turn on the UV-C LED
  delay(10000); // Keep the LED on for 10 seconds
  digitalWrite(uvLedPin, LOW); // Turn off the UV-C LED
  delay(20000); // Keep the LED off for 20 seconds
}

Note: The above code assumes the use of a current-limiting resistor in series with the UV-C LED connected to pin 9 of the Arduino UNO.

• LED Not Emitting Light: Check the power supply and connections. Ensure the current-limiting resistor is correctly calculated and installed.
• LED Overheating: Verify that the current is within the specified range and that adequate heat sinking is provided.
• Shortened Lifespan: Overdriving the LED or operating it without proper heat sinking can reduce its lifespan.

• If the LED is not working, recheck the circuit connections and measure the supply voltage and current.
• Use thermal adhesive or a heat sink to improve heat dissipation.
• Always handle the UV-C LED with care to avoid damage to the diode or the circuit.

Q: Can I use multiple UV-C LEDs in a single circuit?
A: Yes, but ensure each LED has its own current-limiting resistor and that the power supply can handle the total current draw.

Q: How do I know if the UV-C LED is working if I can't look at it?
A: Use a UV-C sensitive card or sensor to detect the presence of UV-C light without directly exposing yourself to it.

Q: Is it safe to use UV-C LEDs at home?
A: While UV-C LEDs can be used safely, precautions must be taken to avoid direct exposure to skin and eyes. Always use proper shielding and follow safety guidelines.