When it comes to managing high currents and voltages in DIY electronics, not all components are created equal. For those who have wandered into the world of high-power electronics—like controlling motors, inverters, or switching large loads—the IRFP4568 is a name that stands out. This rugged and powerful N-channel MOSFET is tailor-made for projects that demand serious switching capabilities. So today, let’s take on a specific project that not only showcases the strengths of the IRFP4568 but also delivers a practical and functional outcome: a heavy-duty DC motor controller for an electric go-kart.
This isn’t just about making something blink or buzz. This is about raw power—tamed and delivered smoothly. Whether you’re building your own go-kart or looking to upgrade a mobility vehicle or electric trike, this project gives you the backbone of a system that can handle serious current without breaking a sweat.

Why IRFP4568?

Before diving into the nuts and bolts of the project, let’s understand the role of the IRFP4568. This component is a power MOSFET capable of handling high voltages and significant currents—up to 195A of continuous drain current and voltage ratings that can go as high as 200V. That’s serious capacity, perfect for DC motor applications in electric vehicle setups.
It also features low on-resistance and excellent thermal stability, making it ideal for hard-working, high-current switching scenarios. This isn’t your average breadboard transistor—it’s built for endurance and heavy lifting.

Project Overview: The DC Motor Controller

The core idea is to build a manual control unit that lets you smoothly operate a powerful DC motor, ideal for an electric go-kart. We’re not going to get tangled in digital signals, Arduino code, or microcontrollers. Instead, the focus is on analog control, using the IRFP4568 as the switching element and pairing it with supporting circuitry that allows for adjustable speed and robust safety measures.
The beauty of this setup lies in its simplicity and power—you’ll have a physical potentiometer for speed control, and the circuitry will be rugged enough to operate a motor that draws dozens of amps without struggling.

Gathering the Components

For this project, the IRFP4568 is the star, but it doesn't work alone. Here's a snapshot of what else you'll need:
●  A 48V DC motor (500W or higher for go-kart application)
●  IRFP4568 MOSFETs (we’ll use 2 in parallel to share the load)
●  A large aluminum or copper heatsink with fan (MOSFETs need cooling!)
●  A high-power gate driver (IR2110 or a gate transformer)
●  Power supply (48V battery pack, lithium or SLA)
●  Potentiometer (10kΩ, linear taper)
●  Flyback diode (something like a 1N1184 or similar high-current diode)
●  Capacitors (electrolytic, around 470µF or more, rated for 63V+)
●  Resistors and signal conditioning components
●  Terminal blocks, wires, and connectors rated for high current
●  An enclosure or mounting base

The Build: Step by Step

Step 1: Designing the Layout
You start by planning out your power path. The IRFP4568s will sit between the motor and the negative terminal of your power source. This configuration—called "low-side switching"—allows for easier gate driving and measurement.
You should place the MOSFETs on a large heatsink immediately. These components, even though efficient, will still generate heat when switching high currents. Secure them with thermal paste and screws, making sure there’s a good thermal path to dissipate energy.
Step 2: Mounting and Wiring the MOSFETs
Wire two IRFP4568s in parallel to share the current load. This involves tying their gates, drains, and sources together—though with small value resistors (like 0.1 ohm) on each source lead to help balance current sharing.
The drain terminals will connect directly to the motor’s negative terminal, while the source terminals will return to the system ground. Between the drain and source, place a large flyback diode to protect against voltage spikes when the motor is turned off.
Step 3: Gate Drive Circuit
The gate of a power MOSFET like the IRFP4568 can’t be driven directly from a potentiometer. It requires a fast, powerful pulse to switch properly. That’s where a gate driver comes in.
Use a gate driver IC like the IR2110 if you want to stay in the realm of analog control but want reliable switching. Alternatively, you can build a simpler push-pull gate drive circuit using bipolar transistors or a gate drive transformer if you're comfortable with transformer winding.
The gate driver’s control voltage is modulated by the potentiometer, which acts as a variable voltage source. As you turn the dial, the voltage to the gate changes, causing the MOSFETs to conduct more or less and thereby controlling the motor speed.
Step 4: Power Filtering
Connect large electrolytic capacitors across the power input terminals to stabilize the supply. Motors draw pulsed current, and without proper filtering, the voltage can drop or ripple enough to cause instability.
Add ceramic bypass capacitors close to the gate driver as well—this ensures the high-speed switching doesn’t cause voltage glitches or electromagnetic interference.
Step 5: Final Assembly and Testing
Secure everything on a non-conductive board or metal chassis. Route power wires away from the signal wires to avoid interference. Use thick gauge wire (at least 10 AWG) for power paths, and double-check all connections.
Before connecting the motor, test the gate drive output with an oscilloscope or voltmeter to ensure it’s switching cleanly. Then attach the motor, and slowly power the system. Start with a low-voltage supply if possible to test behavior before applying full 48V.

Safety Features and Improvements

Once the basic system works, you can add layers of sophistication:

1. Current Sensing: Place a shunt resistor on the source path and add an analog ammeter to monitor current draw.
2. Thermal Cutoff: Use a thermistor or thermal switch mounted on the heatsink to automatically shut off the system if temperatures rise too high.
3. Fuse Protection: Always add a high-current fuse between your battery and motor controller. If something shorts, the fuse will save your components and possibly prevent a fire.
4. Soft Start: A simple RC time delay or a dedicated soft-start circuit can prevent abrupt current surges when the system starts.

Real-World Performance

After installation, you’ll find this controller to be incredibly responsive and robust. The IRFP4568’s fast switching speed ensures smooth acceleration without jitter. Because the control is analog, the system reacts fluidly to your input—no delay, no lag, just pure response.
You’ll also appreciate how cool the MOSFETs run, especially with active cooling. In real-world go-kart tests, these components have easily handled bursts of 100A without any sign of stress—impressive performance for a DIY build.

Applications Beyond Go-Karts

While this build was tailored for an electric go-kart, the controller can be adapted for many other high-power applications:
●  Driving large DC fans or blowers
●  Controlling heating elements
●  Switching power to inverters
●  Battery bank management systems
●  Industrial automation motors
With minimal modification, you could even introduce PWM (pulse width modulation) for finer control—though that would step slightly into the world of microcontrollers or analog oscillators, which we’re not covering here.

Final Thoughts

What makes this project rewarding is not just the functionality but the raw power you get to tame. Building a high-current motor controller isn’t a beginner project, but it’s also not out of reach for a committed hobbyist. The IRFP4568 makes it possible by offering a reliable and resilient backbone for power switching.
No programming, no microcontroller dependencies—just solid-state control the old-school way. This build is a reminder that powerful electronics don't always need to be complicated. Sometimes, all it takes is the right component, a good heatsink, and a bit of hands-on wiring to bring something amazing to life.
And when you finally roll that go-kart out and feel the torque kick in, you’ll know that behind the thrill is a little piece of silicon doing its job, silently and efficiently—just the way it should.