GB1484328A - Circuit for an automatic telegraphic signalling key - Google Patents

Abstract

1484328 Telegraphy; generation of set characters GDANSKIE ZAKLADY ELEKTRONICZNE UNIMOR 18 Dec 1974 [18 Dec 1973] 54797/74 Heading H4P An arrangement for generating set telegraphic characters, e.g. address, alarm, or distress signals comprises a pulse generator 1 producing two outputs in phase opposition stepping a distributing register 2 having the facility of blocking shift pulses. Each output from 2 causes a series of set characters to appear at the output of an encoder 3, e.g. SOS, and a further set of alterable characters, e.g. designation and position of a ship can be set up through a programming circuit 5. Parallel characters from 3 are converted into serial dot-dash signals of the international radio telegraphic code at 4. Each signal issued by 14 releases the register 2 causing issue of the next character. Switch on of the apparatus corresponds to the start of sending an alarm signal which consists of 12 dashes of 4 seconds each with a rest of one second, such signal being formed by appropriate frequency dividers in generator 1. During this time register 2 and coder 3 remain in their initial state. A subsequent impulse from generator 1 causes register 2 to be shifted to its next position thus causing coder 3 to issue the first of its set characters, register 2 being stepped through its stages as each character is transmitted.