Design and development of a current limited solid state hybrid switch

The design and development of the first of a family of hybrid, low power, current limited, spacecraft power supply solid state switches is presented. The thermal protection technique ensures the FET temperature never exceeds a predetermined threshold level under steady state and transient power dissipation operating modes. The design concept of the switch is described and a test method using an infrared thermal imaging technique, and test results which validate the concept are included. Solid state switch developments using this design concept are discussed.