Abstract: A data encoding keyboard for use in electronic processing systems such as electronic calculators includes a pushbutton encoded thumbwheel switch. A plurality of cams secured to the switch define different codes in accordance with the angular orientation of the thumbwheel. The cams engage contacts on a printed circuit matrix adjacent the thumbwheel when the thumbwheel is depressed.

Abstract: A heat-sink assembly adapted for use with a high-power stud-mounted semiconductor device comprises a heat-dispersing arm having one end securely attached to a circuit board and the other end shaped for semipermanent connection and thermal coupling to a heat-conductive stud. The arm is sufficiently bendable to allow displacement thereof from above the surface of the device mounted on the circuit board for removal of the device from the circuit board after disconnecting the other end from the stud while keeping the one end securely attached to the circuit board. The heat-sink assembly may further comprise means for semipermanently connecting the other end of the arm to the stud and retaining the other end in intimate thermal contact therewith.