Zenith Radio Corporation

Zenith Electronics Corporation

Hans E Manske

Joseph N Marchese

James D Domoleczny

Raymond D Loh

Carl A Michelotti

A fast reset degaussing system includes a full wave rectifier bridge having a degaussing coil coupled in series therewith to a source of operating AC power. A variable current element is provided by a field effect transistor which produces a variable load upon the full wave rectifier bridge. An RC charging circuit is coupled to the control electrode of the field effect transistor to cause an exponentially decaying current within the transistor and thereby impose an exponentially load upon the full wave rectifier bridge. The degaussing coil current responds directly to the load imposed upon the rectifier bridge by the field effect transistor and produces an exponentially decaying alternating current suitable for cathode ray tube degaussing.

Fast reset degaussing system

A 'Jacob's Ladder' type spark gap for use in a television receiver or the like includes an alumina substrate having a pair of divergent wires mounted thereon for extinguishing arcs thereacross. The bottom ends of the wires are formed into plug-in terminals. Both upper and lower portions of the wires are supported in suitable apertures in the substrate and soldered to silver pads formed thereon for rigidity purposes. A flameproof housing encloses the substrate and has air vents at the bottom and is open at the top.

High energy discharge sparkgap

An ultra-compact projection television receiver is disclosed comprising in combination cabinet means for enclosing the receiver components including a vertically reciprocable, rear projection viewing screen selectively storable in the cabinet. Precision elevating means provides for raising and lowering the screen between a stored position in the cabinet and a receiver-operable viewing wherein the screen is emerged. A television system has an ON control mode for providing television sound and pictures and an OFF control mode. Control means coupled to the elevating means and the television system provide for sensing the position of the screen in its reciprocation, and obstructions to said reciprocation manifested by increased resistance to said reciprocation, and correlatively controlling the elevating means and the OFF/ON control modes of the television system in response thereto. The control means are programmed to cause the screen to rise smoothly to its raised position without an abrupt stop and pictures to appear and sound to be heard the instant the raised position is attained. Safety is enhanced as obstructions to screen reciprocation are sensed and the reciprocation is stopped. The receiver is caused to automatically place the television system in the OFF mode when the screen is stored.

Precision screen elevating and control means for a projection television

A color television receiver includes a voltage regulating transformer and resonating capacitor for supplying power to receiver circuitry and to a color picture tube subject to extraneous magnetization. An automatic degaussing circuit includes a degaussing coil adjacent to the picture tube, a thermally responsive element and a tuning capacitor, all series connected across a portion of the transformer secondary winding.

Automatic degaussing in television receiver with voltage regulating

A color television receiver includes a voltage regulating transformer having an additional secondary winding coupled to the primary side of the transformer through a thermistor. A degaussing coil is supplied through another thermistor from the main secondary winding. Upon turn-on of the receiver, the additional secondary winding enables substantially higher current flow through the degaussing coil to assist in demagnetization of the permeable material in the picture tube.

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Addison, IL, United States of America

Hans E Manske