How to Use HLK-LD4250: Examples, Pinouts, and Specs

The HLK-LD4250 is a compact, high-efficiency AC-DC power supply module designed for low-power applications. It converts AC voltage (110V/220V) to a stable DC output, making it ideal for powering various electronic devices and circuits. Its small size and high reliability make it a popular choice for embedded systems, IoT devices, and home automation projects.

• Powering microcontrollers (e.g., Arduino, ESP32, Raspberry Pi)
• IoT devices and smart home systems
• LED lighting systems
• Industrial control systems
• Low-power consumer electronics

1. Connect the AC Input:

   • Connect the AC-L pin to the live wire of the AC mains.
   • Connect the AC-N pin to the neutral wire of the AC mains.
   • Ensure proper insulation and safety precautions when working with AC voltage.

2. Connect the DC Output:

   • Use the +5V pin to power your circuit's positive rail.
   • Connect the GND pin to the ground rail of your circuit.

3. Add Filtering Capacitors (Optional):

   • For improved stability, add a 10µF electrolytic capacitor and a 0.1µF ceramic capacitor across the +5V and GND pins.

4. Mounting:

   • Secure the module on a PCB or enclosure to prevent movement and accidental contact with high-voltage pins.

• Safety First: Always handle the module with care when connected to AC mains. Ensure proper insulation and avoid touching live parts.
• Heat Dissipation: Although the module is efficient, ensure adequate ventilation to prevent overheating.
• Load Requirements: Do not exceed the maximum output current of 250mA to avoid damage.
• Isolation: The module provides 3000V AC isolation, making it safe for use in sensitive applications.

The HLK-LD4250 can be used to power an Arduino UNO directly via its 5V pin. Below is an example circuit and code to blink an LED using the Arduino UNO powered by the HLK-LD4250.

1. Connect the +5V pin of the HLK-LD4250 to the 5V pin of the Arduino UNO.
2. Connect the GND pin of the HLK-LD4250 to the GND pin of the Arduino UNO.
3. Connect an LED to pin 13 of the Arduino UNO with a 220Ω resistor in series.

// This code blinks an LED connected to pin 13 of the Arduino UNO.
// Ensure the HLK-LD4250 is properly connected to power the Arduino.

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

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 HLK-LD4250 power a Raspberry Pi?

   • No, the HLK-LD4250 provides only 250mA, which is insufficient for most Raspberry Pi models.

2. Is the module safe for use in home automation projects?

   • Yes, the module is designed with 3000V AC isolation and protection features, making it safe for such applications.

3. Can I use the HLK-LD4250 with a 12V DC output?

   • No, the HLK-LD4250 is specifically designed for a 5V DC output. For 12V, consider other models in the HLK series.

4. Do I need additional components to use the HLK-LD4250?

   • While not mandatory, adding filtering capacitors can improve output stability.

By following this documentation, you can safely and effectively integrate the HLK-LD4250 into your projects.