GB273811A - Improvement in wireless calling up apparatus and in wireless control apparatus - Google Patents

Abstract

273,811. Stevenson, D. A. April 9, 1926. Controlling and actuating fog signals and alarms; calling systems and apparatus; thermionic valve circuits.- Relates to wireless calling-up apparatus and to wireless apparatus for the distant control of fog signals and lights, call bells, alarms, &c., and consists in utilizing a timing-device for switching in the receiver only at predetermined intervals, as by lighting valve filaments. The transmitter may be provided with a synchronous timing- device so that signals are sent only during the periods when the receiver is in condition to receive them. Two or more receivers may be switched into activity in rotation, thus avoiding a complete breakdown if one receiver becomes ineffective. When controlling an automatic fog gun, a clock may be arranged to switch on the valves for a quarterminute every ten minutes; and the gun may be fired by the clockwork during each quarterminute, unless a radio signal is sent and received. The transmitter and receiver clock-switches may be synchronized by wireless signals. In the example shown, the receiving-set comprises a detector valve V<1>, two amplifiers V<2>, V<3> and a final valve V<4> having a sensitive relay W in its plate circuit. This relay closes contacts C<2> C<4> on receipt of a signal impulse, and a sequence of impulses operates the balance-wheel relay B<1> C<1>, of the kind described in Specification 11106/13, and thus selectively controls the relay G<1>. The filament switches S1, S2 are controlled by a timing-device.