GB355706A - Improvements in or relating to electric remote control systems - Google Patents

Abstract

355,706. Distant control systems. MARCONI'S WIRELESS TELEGRAPH CO., Ltd., Marconi House, Strand, London, and WITTS, A. T., Anido, Phyllis Avenue, New Malden, Surrey. May 23, 1930, No. 15936. [Class 40 (i).] The tuning of a radio receiver is controlled from a distance by altering the resistance 1 in a circuit containing a solenoid 6, the armature 7 of which is coupled to the moving plates 10 of a tuning condenser, a rubber plunger 16, Fig. 2, held in contact with the plates by spring 14, being provided to prevent movement of the plates when the solenoid is de-energized. The current supply may be from the set low-tension battery and the scale 3, over which arm 2 moves, may be calibrated in degrees or wavelengths. During tuning operations coil 12 is energized in series with 6, moving armature 13 to withdraw the plunger from the plates. Coil 6 may be shunted with a large capacity condenser to make it slower to release than 12. The armature 7 may be made Z-shaped as shown in Fig. 5, the coil 6 being wound round an iron core 6c with poles 6a, 6b, the armature 7 moving against the action of a spring. Several ganged condensers may be tuned by means of the same remote control device or several control devices may be provided for the same tuning device.