How to Use LRS-50-5: Examples, Pinouts, and Specs

The LRS-50-5 is a 50W single-output switching power supply manufactured by Mean Well. It delivers a stable 5V DC output and is designed for a wide range of applications requiring efficient and reliable power conversion. This compact and lightweight power supply is equipped with built-in protections, including short circuit, overload, and overvoltage protection, ensuring safe and consistent operation.

• Industrial automation systems
• LED lighting and signage
• IoT devices and embedded systems
• Consumer electronics
• Test and measurement equipment

The LRS-50-5 features screw terminal connections for input and output. Below is the pin configuration:

1. Input Connection:

   • Connect the AC mains supply to the AC/L (Live) and AC/N (Neutral) terminals.
   • Ensure the input voltage is within the specified range (85-264 VAC).
   • Optionally, connect the FG terminal to earth ground for improved safety and EMI performance.

2. Output Connection:

   • Connect the load to the +V (positive) and -V (negative) terminals.
   • Ensure the load does not exceed the maximum output current of 10A.

3. Mounting:

   • Secure the power supply in a well-ventilated area to prevent overheating.
   • Avoid placing the unit near heat sources or in environments with excessive humidity.

4. Power On:

   • After verifying all connections, power on the AC mains supply.
   • Measure the output voltage to confirm it is 5V before connecting sensitive devices.

• Load Regulation: Ensure the load is within the rated power range (50W max) to maintain stable operation.
• Ventilation: Maintain adequate airflow around the power supply to prevent overheating.
• Safety: Always disconnect the power supply from the mains before making any wiring changes.
• Fusing: Use an appropriate fuse on the input side for additional protection.

The LRS-50-5 can be used to power an Arduino UNO and other peripherals. Below is an example wiring and code snippet:

1. Connect the +V terminal of the LRS-50-5 to the Arduino's VIN pin.
2. Connect the -V terminal of the LRS-50-5 to the Arduino's GND pin.
3. Ensure the LRS-50-5 is properly connected to the AC mains supply.

// Example code to blink an LED connected to pin 13 of the Arduino UNO
// Ensure the LRS-50-5 is providing a stable 5V to the Arduino's VIN pin

void setup() {
  pinMode(13, OUTPUT); // Set pin 13 as an output
}

void loop() {
  digitalWrite(13, HIGH); // Turn the LED on
  delay(1000);            // Wait for 1 second
  digitalWrite(13, LOW);  // Turn the LED off
  delay(1000);            // Wait for 1 second
}

1. Can the LRS-50-5 be used with DC input?

   • Yes, the LRS-50-5 supports DC input in the range of 120-370 VDC.

2. Is the output voltage adjustable?

   • Yes, the output voltage can be fine-tuned using the built-in potentiometer.

3. What type of fuse should I use on the input side?

   • Use a fuse rated for 3A at 250V for optimal protection.

4. Can I use the LRS-50-5 outdoors?

   • The LRS-50-5 is not weatherproof. Use it in a dry, indoor environment or within a suitable enclosure.

By following this documentation, users can effectively integrate the LRS-50-5 into their projects and ensure reliable operation.