Control and Power Electronics for a Two-Stage Turbo-Brayton Cryocooler for Space Applications

Last year saw the successful demonstration of an autonomously controlled two-stage turbo-Brayton cooler. The electronics developed for this demonstration evolved from the seminal work of the NICMOS cryocooler, the first flight-qualified turbo-Brayton cryocooler. Two key features of the electronics are the ability to control temperature without the use of trim heaters and the ability to recover expander power back to the main power bus. The development of the control and power electronics for this two-stage cooler was the first step toward a space qualifiable design. The technical challenges, solu- tions and performance of the electronics for the two-stage turbo-Brayton cooler are presented.