How to Use Gravity: MOSFET Power Controller: Examples, Pinouts, and Specs

The Gravity: MOSFET Power Controller (Manufacturer Part ID: DFR0457) by DFROBOT is a versatile and efficient power management module designed for controlling high-power loads in electronic circuits. It leverages the capabilities of MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) to provide high-speed switching, low power loss, and reliable operation. This module is ideal for applications requiring precise power control, such as motor drivers, LED lighting systems, and heating elements.

• Driving high-power LEDs or lighting systems
• Controlling DC motors or actuators
• Power management in IoT devices
• Switching high-current loads in automation systems
• Heating element control in temperature regulation systems

The following table outlines the key technical details of the Gravity: MOSFET Power Controller:

The module features a simple pinout for easy integration into your projects:

1. Power Connections:

   • Connect the VIN pin to the positive terminal of your power source (e.g., battery or power supply).
   • Connect the GND pin to the ground terminal of your power source and load.
   • Connect the VOUT pin to the positive terminal of your load (e.g., motor, LED, or heating element).

2. Control Signal:

   • Use a microcontroller (e.g., Arduino UNO) or other logic-level device to send a control signal to the SIG pin.
   • A HIGH signal (3.3V or 5V) will turn the MOSFET ON, allowing current to flow through the load.
   • A LOW signal will turn the MOSFET OFF, cutting off current to the load.

3. Heat Dissipation:

   • For high-current applications, ensure proper heat dissipation by attaching a heatsink to the MOSFET or using active cooling.

• Voltage Compatibility: Ensure the input voltage (VIN) is within the module's operating range (3.3V to 20V).
• Current Handling: Do not exceed the maximum load current of 30A. Use proper heat dissipation for high-current loads.
• Signal Voltage: The control signal should be 3.3V or 5V logic level. Avoid applying higher voltages to the SIG pin.
• Switching Frequency: For applications requiring high-speed switching, ensure the control signal frequency does not exceed 20kHz.

Below is an example of how to control the Gravity: MOSFET Power Controller using an Arduino UNO to drive a 12V LED strip.

• Connect the VIN pin to a 12V power supply.
• Connect the VOUT pin to the positive terminal of the LED strip.
• Connect the GND pin to the ground of the power supply and Arduino.
• Connect the SIG pin to a PWM-capable pin on the Arduino (e.g., Pin 9).

// Define the control pin for the MOSFET Power Controller
const int mosfetControlPin = 9;

void setup() {
  // Set the MOSFET control pin as an output
  pinMode(mosfetControlPin, OUTPUT);
}

void loop() {
  // Gradually increase brightness (PWM duty cycle)
  for (int brightness = 0; brightness <= 255; brightness++) {
    analogWrite(mosfetControlPin, brightness); // Send PWM signal
    delay(10); // Small delay for smooth transition
  }

  // Gradually decrease brightness
  for (int brightness = 255; brightness >= 0; brightness--) {
    analogWrite(mosfetControlPin, brightness); // Send PWM signal
    delay(10); // Small delay for smooth transition
  }
}

1. The load does not turn ON:

   • Ensure the power source is connected and providing the correct voltage.
   • Verify that the control signal (SIG pin) is HIGH (3.3V or 5V).
   • Check all connections for loose wires or poor solder joints.

2. The MOSFET overheats:

   • Ensure the load current does not exceed 30A.
   • Attach a heatsink or use active cooling for high-power applications.

3. The module does not respond to the control signal:

   • Confirm that the control signal voltage is within the acceptable range (3.3V or 5V).
   • Check the Arduino code or microcontroller configuration for errors.

4. PWM control is not smooth:

   • Ensure the control signal frequency does not exceed 20kHz.
   • Verify that the load is compatible with PWM control.

Q: Can I use this module with a 24V power source?
A: No, the maximum input voltage for this module is 20V. Using a 24V power source may damage the module.

Q: Is the module compatible with 3.3V microcontrollers like the ESP32?
A: Yes, the SIG pin is compatible with both 3.3V and 5V logic levels.

Q: Can I use this module to control an AC load?
A: No, this module is designed for DC loads only. Do not use it with AC loads.

Q: What is the maximum switching frequency?
A: The module supports switching frequencies up to 20kHz.