How to Use HLK-PM12: Examples, Pinouts, and Specs

The HLK-PM12 is a compact, highly efficient AC-DC power supply module designed to convert alternating current (AC) from the mains to a stable 12 Volt direct current (DC). This module is widely used in low power applications such as smart home devices, control systems, and IoT projects due to its small form factor and ease of integration into existing circuits.

• Smart home automation systems
• IoT devices
• LED lighting
• Industrial control systems
• Standalone microcontroller power supplies

The HLK-PM12 module boasts the following technical specifications:

1. AC Input Connection: Connect the AC live wire to pin 1 (L) and the neutral wire to pin 2 (N). Ensure that the connections are secure and insulated to prevent electrical hazards.

2. DC Output Connection: Connect the positive lead of your device or circuit to pin 4 (+V) and the negative lead to pin 3 (-V).

3. Mounting: Secure the HLK-PM12 module onto a PCB or within an enclosure, ensuring adequate ventilation for heat dissipation.

• Always verify the mains voltage compatibility before connecting the module.
• Ensure that the total load does not exceed the module's maximum output current of 3A.
• Avoid placing the module in environments with extreme temperatures or high humidity.
• Isolate the AC side from the DC side to prevent electrical shock or damage to the connected devices.
• Use a fuse on the AC input for additional safety.

• No Output Voltage: Check AC input connections and verify that the mains supply is within the specified range.
• Overheating: Ensure the module is not overloaded and that there is adequate ventilation.
• Output Voltage Fluctuations: Verify that the load does not exceed the module's capacity and check for loose connections.

• If the module overheats, disconnect it immediately and check the load conditions.
• Use a multimeter to check the output voltage and ensure it is stable at 12V DC.
• Consider adding a heat sink or additional cooling if the module is operating near its maximum power rating for extended periods.

Q: Can I use the HLK-PM12 outdoors? A: The HLK-PM12 is not waterproof and should be housed in a suitable enclosure if used outdoors.

Q: Is it necessary to use a fuse with the HLK-PM12? A: Yes, it is recommended to use a fuse on the AC input for safety purposes.

Q: Can I adjust the output voltage of the HLK-PM12? A: No, the output voltage is fixed at 12V DC.

// No specific code is required for the HLK-PM12 as it is a power supply module.
// However, below is an example of how to power an Arduino UNO using the HLK-PM12.

// Connect the HLK-PM12 module to the Arduino UNO as follows:
// HLK-PM12 +V pin to Arduino UNO Vin pin
// HLK-PM12 -V pin to Arduino UNO GND pin

void setup() {
  // Initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  // Turn the LED on (HIGH is the voltage level)
  digitalWrite(LED_BUILTIN, HIGH);
  // Wait for a second
  delay(1000);
  // Turn the LED off by making the voltage LOW
  digitalWrite(LED_BUILTIN, LOW);
   // Wait for a second
  delay(1000);
}

Note: When using the HLK-PM12 to power an Arduino UNO, ensure that the input voltage does not exceed the recommended Vin range for the Arduino UNO (6-20V). The HLK-PM12's 12V output is within this range and is suitable for powering the board.