D4184 MOSFET Control Module – PC817 Optoisolated N-Channel Power Switch 6–36V 10A

The D4184 MOSFET Control Module is an optoisolated DC power switching board designed to control higher-current loads from a low-voltage PWM or digital signal. The module uses a PC817 optocoupler between the control input and MOSFET switching circuit, providing electrical isolation between the two sides.

Features

• N-channel MOSFET power switching.
• PC817 optoisolated control input.
• 2.5–20V control input range.
• Compatible with common 3.3V and 5V logic systems.
• 6–36V DC load supply range.
• Low RDS(on) for reduced conduction losses.
• Suitable for ON/OFF and PWM control.
• Low-side switching configuration.
• Screw-terminal connections for power and load.
• Compact 35 × 16 × 14mm design.
• Suitable for Arduino, ESP32, STM32, and other controllers.

Applications

• DC motor control.
• Solenoid control.
• LED array switching and PWM dimming.
• DC fan control.
• Relay switching.
• Robotics projects.
• Industrial and automation prototypes.
• IoT power-control systems.
• Arduino and ESP32 projects.
• Battery-powered DC load switching.

How It Works

The controller sends a HIGH PWM or digital signal to the module's PWM input. This activates the LED inside the PC817 optocoupler. The optocoupler then drives the MOSFET switching circuit while maintaining electrical separation between the logic input and load circuit.

The module performs low-side switching. The positive side of the load connects to the positive terminal of the external DC supply, while the module switches the load's negative side.

Logic connections:

• PWM → Microcontroller digital/PWM output.
• GND → Microcontroller signal ground.

Load power connections:

• + → Positive terminal of the external 6–36V DC supply.
• – → Negative terminal of the external DC supply.

Load connections:

• + → Positive lead of the load.
• LOAD → Negative lead of the load.

The optoisolator keeps the logic-side ground electrically separated from the load-side power ground.

Important Notes

• This is a low-side switch, not a high-side power switch.
• The module should not be treated as a 50A continuous-current board simply because the MOSFET itself has a much higher theoretical current rating. The small PCB and thermal conditions limit practical current.
• The stated 10A capability depends on voltage, duty cycle, PCB temperature, airflow, wiring, and load characteristics.
• The AOD4184-family MOSFET has a 40V VDS rating; keeping the module's load supply at or below the stated 36V recommendation provides additional margin.
• The MOSFET's low RDS(on) specification is dependent on gate voltage and operating conditions; it should not be interpreted as the same resistance under every input voltage.
• Use an appropriate flyback diode across inductive loads such as solenoids, relays, and suitable DC motors.
• Do not short the load output terminals.
• Ensure the power supply can provide the required load current.
• Use appropriately sized wires and screw-terminal connections for high-current applications.
• The module can become hot at high current. Provide airflow or additional thermal management when necessary.
• PWM frequency and duty cycle should be selected according to the load and switching requirements.
• Product appearance and terminal/header configuration may vary slightly between batches.
• Allow approximately 5% deviation for manual measurements.

Package Includes

• 1 × D4184 MOSFET Control Module