Cooking with high voltage
This is based on resistive heating of food when current passes through it. Since the resistance of most foods is large, high voltage is needed to get any appreciable power dissipation.
The aparatus is composed of a high voltage transformer removed from a broken microwave and two electrodes which are inserted into the food. The setup can deliver 1.8kW of power.
This technique was sucessfully demonstrated by Walker Chan to win the "what a way to die" category in the 2005 EC Apple Bakeoff.
For CPW 2006, slugs built a Jacob's Ladder out of two microwave transformers and two pieces of copper pipe. The transformers were connected with their primaries in parallel and their secondaries in series. In order to keep the line current below 15A, a large electromagnet was wired in series with the transformers.
The Jacob's Ladder could be electrically triggered by applying a high current pulse to a third winding (originally intended for the filament heater in the microwave) on one of the transformers.