A homemade EMF generator built around a Marx generator and custom transformer offers an interesting look at the science behind electromagnetic interference. A maker on YouTube known as Skill Make has showcased an experimental high-voltage electromagnetic pulse generator built using a combination of a custom transformer, a Marx generator, and a directional antenna coil. The project explores how rapidly discharged electrical energy can generate strong localised electromagnetic fields capable of interfering with nearby electronics. Rather than being a large-scale EMP device, the build serves as a practical demonstration of high-voltage engineering concepts and pulse power technology using readily available components.
The system begins with a custom-built step-up transformer featuring a 9-turn primary winding and a 12,000-turn secondary winding, resulting in a voltage multiplication ratio of approximately 1:1,333. To prevent insulation breakdown at high voltages, the transformer is encapsulated in vacuum-degassed epoxy resin. A flyback-style driver circuit powered by an 8V battery pack uses pulse-width modulation (PWM) at 12.5 kHz to switch current through the transformer via a power MOSFET. The resulting high-voltage output is rectified into DC and fed into an eight-stage Marx generator, where multiple capacitors charge in parallel and then discharge in series through spark gaps, producing a very short but high-energy voltage pulse.
To radiate this pulse, the output is connected to a flat pancake coil backed by a metallic reflector designed to direct more of the electromagnetic field toward a target. During testing, the creator exposed several consumer devices, including a digital calliper, an LCD calculator, and a smartwatch, to the generated pulses. While the demonstrations showed that sensitive electronics can be affected or damaged at close range, the project primarily highlights the challenges of storing, switching, and directing high-voltage energy. It also provides an interesting look into transformer design, Marx generators, pulse discharge systems, and electromagnetic field generation, all within the context of a laboratory-style engineering experiment.
