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Abstract

This work is concerned with the design of counters built on electromagnetic relays, having two input switches, and indicating the difference between the numbers of times the input switches have been operated, modulo some number, the scale of the counter. The methods used are those for the design of ‘sequential switching circuits’ introduced by Huffman and subsequently developed by him and others.

Several kinds of design are presented. These are:-

(a) a routine design using the minimum number of secondary relays, that is, five. In the course of this the number of four-digit Gray codes of length ten has been determined.

(b) designs using a single transfer contact for each input, in which

(i) the relays are paired so as to form distinct flip-flops, and

(ii) the relays are not so paired.

All the above designs use series-control only.

(c) designs using τ-flip-flops having combined series- and shunt-control. The design-process for a counter of any length has been reduced to a simple exercise in combinational logic.

Finally, some comments are offered on the problems likely to be met in the practical realisation of the designs, and the steps to be taken to avoid hazards.

Publication Type:	Thesis (Doctoral)
Subjects:	Q Science > QA Mathematics > QA75 Electronic computers. Computer science T Technology > TK Electrical engineering. Electronics Nuclear engineering
Departments:	School of Science & Technology > Department of Engineering School of Science & Technology > School of Science & Technology Doctoral Theses Doctoral Theses

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