Electronic controller for linear cryogenic coolers

Abstract From the Canadian patent

A highly efficient motor driver circuit of an electronic controller for linear cryogenic coolers operates directly from a variable power supply such as a batter, without the need for the voltage regulator control circuit of the prior art. Elimination of the prior art voltage regulator ensures a higher efficiency motor driver circuit of the electronic controller. Both open-loop and closed-loop controllers electronically control the motor driver circuit. The open-loop controller protects against temperature sensor failure and will limit maximum motor power as a function of system ambient temperature. The closed-loop controller regulates the temperature of the cold finger accurately to a …