GB259262A - Improvements in means for obtaining reduced voltage electric supply from a unidirectional current source for wireless systems & other purposes - Google Patents

Abstract

259,262. Blake, G. G., and Wood, L. Rusell-. May 8, 1925. Converting pulsating currents into steady continuous currents.-Current at a reduced voltage for operating thermionic valves or for other purposes is obtained from a direct or rectified-alternating current supply by arrangements shown in Fig. 2. The input terminals A, B are connected through radio-frequency chokes C, C<1> and iron-cored chokes K,K<1> to a potentiometer T, from which current may be taken to one or several filament circuits direct or through an independent rheostat R. The " earth '' terminal of a wireless apparatus is disconnected and a connection made to earth through a condenser X from either or both sides of the potentiometer. Alternatively a condenser may be placed in the usual earth connection. Current for the plate circuits may be taken from a second potentiometer Q, supplied through other radio-frequency chokes C, C<1> and one or both iron-cored chokes K. An iron-cored choke Z is placed in the lead from the potentiometer as shown. A condenser J is connected across the output terminals. A condenser M is connected between " low-tension " and " hightension " negative terminals to enable the combination to be used with sets in which the positive low-tension and negative high-tension terminals are connected together. A small safety lamp or fuse L<1> is connected in the " high-tension " supply. L is an indicating lamp.