Abstract: A semiconductor and heat sink assembly of the type having two groups of semiconductor devices only one group of which is operable at any instant in time has the semiconductor devices arranged, with respect to the heat sink portion of the assembly, in a divided manner such that maximum utilization is made of the heat sink to thereby provide improved duty cycle capabilities.

Abstract: A circuit for generating a signal proportional to the average current of an inductive load supplied from a supply of intermittent electrical power and having a free-wheeling path through which load current flows during periods in which the load is not connected to the power supply, includes means to provide a first signal which is a function of the current in the free-wheeling path and second means to provide a second signal which is a function of the supply-load current. By appropriately combining the two signals an output proportional to the average load current is obtained. The output signal can be utilized for control functions such as controlling the operation of switching devices which, in turn, control the application of electrical power to a d.c. motor.