Abstract: A pictorial element display assembly adapted for mounting in a matrix of similar assemblies to present a character by transmitted and/or reflected light. The assembly has a rectangular opaque panel formed with a pocket defining a window in which is set a colored plate for displaying the illuminated pixel. A pair of light spot projecting caps set in keyhole shaped slots in the colored plate have parallel, coplanar axes aligned on a central axis midway between lateral edges of the panel. A D-shaped gate is rotatable through 180.degree. by an electromagnetic device, to open and closed positions on the window and on the panel for selectively uncovering and covering the covered plate. The caps engage ends of light transmitting fiber cords which carry light from a light source to project the light as light spots in intense beams out of central holes in ends of the caps. The axis of rotation of the gate is parallel to and spaced laterally from the central axis of the colored plate, away from the colored plate.

Abstract: This graphic character matrix display assembly has a support providing a nonreflecting background for a multiplicity of display units arranged for cooperatively displaying the character. Each of the display units comprises a flat display disk having opposite sides. An electromagnet rotates the disk between display position and reversed position. A light source at each disk projects a light beam through a peripheral cutout in the disk when the disk is in display position. The light beam also projects an outline of the disk by backlighting. The periphery of the disk blocks the light beam when the disk is in reversed position. The light source for each disk may be an incandescent lamp, emitting diodes or the end of a light pipe.

Abstract: This improved heat dissipator for mounting a semiconductor unit is made of sheet metal laminated with eutectic metal coatings. The dissipator has a planar base, narrow platelike wings, springy tabs for engaging ends of the unit, and rigid laterally angled legs. The legs bond to laterally extending metal legs of the semiconductor unit.

Abstract: This matrix system and method for displaying graphic characters has a vertical panel with openings arranged in a rectangular array. At each opening is a display disk rotatable 180.degree. in a path between a non-reflective upright forward facing first position, and a light reflective upright forward facing second position. Each disk is turned on a horizontal axis and can be stopped in horizontal position midway in the path of disk rotation by an electromagnetically extensible and retractable stop member. The disks are turned by interaction between an electromagnetically energized magnetic core, and a permanent magnet rotatable with the disk. Lamps behind the disk can project back light through the openings when the disks are in midway positions to display graphic characters. Retraction of the stop members allows selected disks to turn to an upright light reflective position, to display graphic characters by ambient reflected light, while remaining disks provide a light blocking non-reflective background.

Abstract: A heat dissipating retainer for a flat, rectangular solid state package of electronic components is made from a single piece of pliable, springy electrically conductive sheet material bent to form a generally W-shaped structure. This structure has an inner inverted U-shaped channel section open at its front, back, and bottom ends to receive the package in frictional engagement under spring tension by contact with sides of the channel section. This structure serves as a heat sink by effectively dissipating by conduction, convection and radiation, heat generated in the solid state package of electronic components.

Abstract: A rotor for an electromagnetic indicator comprises a flat circular disk made of thin, pliable, nonmagnetic material. The disk has integral tabs extending out of diametrically opposite edges and a rib extends diametrically of the disk to outer ends of the tabs. The rib and tabs define T-shaped trunnions which engage in T-shaped slots in respective sides of a rotary magnet, and a journal block. The disk is fabricated from a single flat sheet having flat tabs extending outwardly of opposite edges. A V-shaped groove is made in the sheet extending centrally across the disk and tabs. Opposite sides of the groove are then brought together to form the rib with T-shaped trunnions at opposite edges of the disk.

Abstract: An electromagnetic indicator has a stator carrying a stationary reversibly magnetizable core, and a rotor including a display disk and rotary cylindrical magnet. The magnet is permanently magnetized with two poles each angularly spaced apart less than 180.degree. at one side of a diameter of the magnet which also passes through the radially located core. Stop elements carried by the stator and core are engaged in each stopping position of the rotor when one of the magnet poles is attracted to, but held spaced from the magnetized core. The poles can be located to effect a turning range of the rotor from 120.degree. to 250.degree..

Abstract: A magnetic indicator assembly has a casing containing a stator comprising a reversibly magnetizable core carrying a wire coil. A rotor is angularly turnable around said casing through an angle of approximately 120.degree. to expose either one of two flags carried by the rotor on angularly disposed walls of a nonmagnetic member. The rotor carries a block supporting two coplanar, aligned bar magnets oppositely polarized. Either one of the magnets is attracted to the core depending on the polarity of the magnetic circuit as determined by the energization of the wire coil.

Abstract: The device comprises a body portion formed of a pair of substantially parallelly situated planar members spaced to receive the tab therebetween such that the interior surface of each member is parallel to and in engagement with the exterior surface of the tab adjacent therewith. In this manner, optimum heat transfer is achieved because the surface area of contact between the members and the tab is maximized by causing both sides of the tab to be in a heat conductive relationship with the device. Resilient connecting means situated at the ends of the members variably space the planar members with respect to each other such that tabs of different thicknesses can be accommodated and at the same time the parallel relationship between the members is maintained regardless of the spacing of the members to assure that the contact area is always maximized.