GB399566A - Improvements in or relating to luminous electric discharge tubes, signs and designs - Google Patents

Abstract

399,566. Supply and control systems for vacuum &c. discharge apparatus. ADAMS, G. C., Coombe Cottage, Willow Crescent East, Willow bank, Uxbridge, Middlesex, and WARNER, A. R., 29, Abbey Road, St. John's Wood, London. April 12, 1932, No. 10524. [Class 38 (iv).] In apparatus for producing variations in a neor or like sign E by means of an oscillatory circuit associated with a thermionic valve V, the variations are produced by varying the voltage applied to the valve anode or by varying the flow of electrons to the anode. As shown, the valve filament current is varied by means of a resistance R<1> or potentiometer P<1> which may be varied automatically by means of a motor or clockwork- The resistance &c. may be in the circuit of a transformer primary, the secondary of which energizes the filament. In another arrangement, the filament has a temperature lag, and a switch, operated'mechanically, electrically or thermally, for example by a bimetallic strip, is connected in the filament circuit. In other arrangements, (a) the variable resistance or potentiometer is connected between the high tension supply and a point t in the primary P, (b) the grid leak is variable, or (c) the variable resistance &c. is in the circuit of a primary having one secondary connected between the point t and the filament, and another secondary supplying the filament. Several lamps, each with a separate valve generator, may have their control units operated by single motor, so that they will light up gradually in turn.