The system uses a computer to direct the electromagnetic engine valves and varies the amount of air pushed through the engine. A controller determines the fuel usage and the technique to maximum horsepower. Inc. has designed and developed a three-stage cryocooler. Incoming gas is cooled regeneratively mainly in the first two stages. A displacer and the cylinder walls act as the regenerator.
Gas flowing into the third stage is cooled by a counter flow heat exchanger.
Cooling is achieved by a three-stage expansion engine with a single displacer and liquid helium produced by expansion in the third stage. The system consists of a compact cold head operating with a single helium flow circuit and compressor. References Personal letter, November 19, 1994. A springplate is provided to allow for replaceability of the actuator. The loading force is transmitted to the springplate with a spherical cap.