How to Use MW LRS-350-12: Examples, Pinouts, and Specs

The MW LRS-350-12 is a high-performance 12V DC switching power supply manufactured by MEAN WELL. It is designed to deliver a stable and reliable 12V output with a maximum current of 29A, making it ideal for a wide range of electronic applications. Its compact design, high efficiency (up to 89%), and built-in safety features ensure dependable operation in demanding environments.

• Powering LED strips and lighting systems
• Industrial automation equipment
• 3D printers and CNC machines
• Security systems and surveillance cameras
• General-purpose DC power supply for electronics projects

The following table outlines the key technical specifications of the MW LRS-350-12:

The MW LRS-350-12 features screw terminal connections for input and output. The table below describes the pin configuration:

1. Input Connection:

   • Connect the AC input terminals (L and N) to the mains power supply.
   • Ensure the input voltage is within the specified range (85-264VAC).
   • Connect the FG terminal to earth ground for safety.

2. Output Connection:

   • Connect the +V and -V terminals to the load requiring 12V DC power.
   • Ensure the load does not exceed the maximum output current of 29A.

3. Voltage Adjustment:

   • Use the V ADJ potentiometer to fine-tune the output voltage within ±10% of 12V (10.8V to 13.2V).

4. 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.

• Cooling: The MW LRS-350-12 relies on natural air convection for cooling. Ensure adequate airflow around the unit.
• Overload Protection: The power supply includes built-in overload protection. If the load exceeds the rated current, the output will shut down temporarily. Reduce the load and restart the unit.
• Safety: Always disconnect the power supply from the mains before making any connections or adjustments.
• Fuse: Use an appropriate fuse on the AC input side to protect against overcurrent conditions.

The MW LRS-350-12 can be used to power an Arduino UNO and other peripherals. Below is an example circuit and Arduino code:

1. Connect the +V terminal of the power supply to the Arduino's VIN pin.
2. Connect the -V terminal of the power supply to the Arduino's GND pin.
3. Ensure the output voltage is set to 12V using the V ADJ potentiometer.

// Example code to blink an LED connected to pin 13 of the Arduino UNO
// Ensure the MW LRS-350-12 is providing a stable 12V DC to the Arduino

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 MW LRS-350-12 be used outdoors?

   • No, the power supply is not waterproof. Use it in a dry, indoor environment or within a weatherproof enclosure.

2. What is the maximum load this power supply can handle?

   • The maximum load is 348W (12V at 29A). Exceeding this limit will trigger overload protection.

3. Can I use this power supply to charge batteries?

   • Yes, but ensure the charging voltage and current are within the battery's specifications. Use a charge controller if necessary.

4. How do I reset the power supply after overload protection is triggered?

   • Disconnect the load, power off the unit, and wait a few seconds before restarting.

By following this documentation, users can safely and effectively integrate the MW LRS-350-12 into their projects.