Here is a simple breakout board for the IRF520 Mosfet. Easy hookup to your Arduino or other 3-5v micro controller. Pulse current through a PWM pin, and use this to control a pump, LED, or other DC device at up to 24v, and ~5A. (You can check the specs here)

Real simple to use: The simplest way of explaining how this little board works is this: You connect the power for the device you want to control to the Vin and GND. You connect your device to the V+ and V- screw terminals. When the SIG line is HIGH, a little LED lights up, and the GND is 'connected' to the V-. When the SIG line is LOW, the LED turns off, and the GND becomes 'disconnected' to the V-. The V+ and Vin are continuously connected.

You can power this device from your Arduino, VCC goes to the 5V connection, and GND to the GND pin on your Arduino.

Features:

• Voltage: 3.3V, 5V
• Output load voltage :0-24V
• Output load current: <5A (1A and above requires a heat sink)
• Platform: Arduino, MCU, ARM, Raspberry PI.
• Using original IRF520 Power MOS, you can adjust the output PWM.
• Drive up to 24V allows the load, such as LED lights, DC motors, miniature pumps, solenoid valves.
• PWM dimming LED can be used to achieve step less dimming, variable speed motor control.Note: Above 1 A load, you need to install heat sink.