Abstract: An in-circuit test fixture for use in making a non-functional electrical inspection of individual components and/or circuit paths on a printed circuit board or wired backpanel assembly. The present in-circuit test fixture is cost effective and can be used when only small or moderate numbers of printed circuit boards have to be tested. The present test fixture eliminates the necessity for drilling holes in a support plate. Rather, a test head unit and a transition head unit are put together in modular fashion using assemblies which may be positioned in stacked arrays to provide a two-dimensional series of channels for support of pins to provide a test head for testing a two-dimensional product and to provide a two-dimensional series of channels for support of pins to provide a transition head for interconnection with an electronic circuit analyzer.

Abstract: In an in-circuit test fixture of the type including a bed of pins, first ends of which are adapted to contact a circuit board, means for supporting the pins, and means for making electrical connection thereto, there is disclosed an improvement wherein the pins are solid members and are freely slideable in the supporting means and wherein the test fixture includes a sheet of resilient material engaging second ends of all of the pins for providing the force necessary to urge the pins into contact with the circuit board. The means for supporting the pins includes a modular assembly which forms channels for the pins and eliminates the necessity for drilling holes in a board. The modular assembly includes a circuit board and a plurality of spring contacts for making electrical connection to the solid pins.

Abstract: An inexpensive, highly efficient, durable, and easy to manufacture solar collector of the flat-plate type. The collector includes a heat exchanger having an upper plate, a lower plate, and four triangularly-shaped side plates defining an enclosed chamber, all plates being highly absorbent of solar radiation, the upper plate curving inwardly so that a central portion thereof extends closely adjacent the lower plate along a hot line extending between opposite corners of the collector; and means for conducting a fluid into and out of the chamber, at the remaining corners thereof, on opposed sides of the hot line, so that the fluid flows through the chamber, perpendicular to and in a thin sheet past the hot line, absorbing heat from the upper plate. The collector also includes a frame in which the heat exchanger is supported along the outer edges only in a manner such that light is reflected to the lower plate to increase the efficiency of heat absorption.