Abstract: A fault-tolerant power distribution architecture is described in which electrical power-consuming modules are connected in rows via individual busses in a first set of busses connected to individual power supplies in a first set of power supplies, and are also connected in columns via successive busses in successive sets of busses connected to power supplies in successive sets of power supplies such that each module receives power from a unique combination of a first bus and a first power supply and a successive bus and successive power supply.

Abstract: Test pins with sidewardly biased plungers to insure electrical contact.

Abstract: A fastener for use with a connecting element such as a screw comprises a thickened head of a firm but plastic material, a shank, and a tail. The head and shank are first placed into a hole; then a connecting element such as a screw is inserted alongside of the head to cause the head to wedge into the wall of the hole and hold the screw tightly. In one aspect the shank and tail are connected by an indented portion that facilitates breaking away the tail and indicates the desired depth of insertion of the head, and in another aspect the head contains a second, harder material to facilitate the wedging action of the head.

Abstract: An electrical tester for circuit boards in which test pins are mounted in a support derived from a corresponding unloaded circuit board and in which wires to the test pin run slidably in interfitting pairs of plastic sleeves.

Abstract: An electrical tester for circuit boards in which test pins are mounted in a support derived from a corresponding unloaded circuit board and in which wires to the test pin run slidably in interfitting pairs of plastic sleeves.

Abstract: Slip coupling incorporating bearing-quality friction surfaces and a flexible structure that isolates torsional vibration.

Abstract: Capacitive phase shift circuitry for supplying current to the two coils of a synchronous motor at a desired voltage and phase relation, without the need for a voltage drop resistor.

Abstract: Circuit board testing apparatus featuring an improved weighting assembly for holding a circuit board in contact with test pins.

Abstract: An electrical testing pin characterized by a crown with an inner contact area and a plurality of outer contact areas, the former extending longitudinally beyond the latter.