Abstract: A heat sink assembly is described for cooling right cylindrical packages containing high power semiconductor devices. Opposite end faces of the packages cooperate with heat sink members to provide liquid coolant flow channels in which the liquid coolant is in direct contact with the package end face. A unique compact elastomeric coolant manifold facilitates semiconductor device replacement in the assembly. The assembly, including the elastomeric manifold, is enclosed in a container and maintained submerged in coolant during use.

Abstract: In a cycloconverter system, a circuit for maintaining the gate drive signal on the gate of each controlled rectifier when the gate drive command for the controlled rectifier terminates prior to the time when the controlled rectifier would normally become conductive. Voltages across the controlled rectifier are monitored by voltage sensors. Logic circuits are provided which are responsive to the outputs of the voltage sensors and the presence of gate drive commands for maintaining a gate drive signal on the gate of a controlled rectifier when the gate drive command for the controlled rectifier terminates after the controlled rectifier reverse blocks and until it becomes conductive.