DOI:10.1049/ree.1969.0023

出版商:IERE    

年代:1969

数据来源: IET

DOI:10.1049/ree.1969.0024

出版商:IERE    

年代:1969

数据来源: IET

DOI:10.1049/ree.1969.0025

出版商:IERE    

年代:1969

数据来源: IET

摘要:

The aim of this paper is to bring forward and analyse phenomena occurring in a television receiver as a result of a flashover inside a picture tube, and to evolve a systematic approach to a method of protection. The paper first reviews the behaviour of a picture tube under flashover conditions, its effect on receiver circuitry, and a suggestion is made for a possible equivalent circuit. It then establishes a comprehensive method of protection against the large transients generated by a flashover which affect primarily a portion of the receiver directly connected to the base of the picture tube. This protection consists of a separate path for flashover currents, which is switched into circuit for the duration of flashover by means of spark-gaps assisted by series resistors. It is connected in such a way as to provide a minimum disturbance to the rest of the receiver. Further, the paper considers overloads imposed on the e.h.t. generator as a result of discharge of the e.h.t. capacitor by a flashover of the picture tube or other agency. Proposals are made for suitable limiters to protect the output transistor. Finally, a description of some measuring techniques of particular interest in flashover work is given.

DOI:10.1049/ree.1969.0027

出版商:IERE    

年代:1969

数据来源: IET

摘要:

This paper is an account of an attempt to perform logic at very high speed (250 MHz) using tunnel diodes. The basic circuit, a derivative of the Goto pair, is described and the rather limited logic power of such an element defined. An account is given of a suitable application for a small amount of very high speed logic, namely a variable microprogram control unit for a transistor digital computer. A brief description of the incorporation of the tunnel diodes in the machine follows.The microwave diodes used were found to be too unreliable for largescale use in a digital computer. By careful selection from a large number (5000) of diodes, 700 logic elements were constructed and interconnected, to confirm the circuit analysis and logic rules. It is concluded that in the event of reliable microwave tunnel diodes becoming available in large numbers they could be used in the described manner to perform logic at 250–300 megabit rates and 1 ns stage delays.

DOI:10.1049/ree.1969.0028

出版商:IERE    

年代:1969

数据来源: IET

摘要:

The R-C active filters investigated use operational amplifiers as the active element and are capable of realizing second-order network functions with no finite transmission zeros. One of the networks uses positive feedback; another uses negative feedback (from an amplifier of nominally infinite gain); two use both positive and negative feedback (from a paraphase amplifier of nominally infinite gain); the fifth uses a combination of three amplifiers all of nominally infinite gain; the sixth uses a four-amplifier realization of a gyrator, again all of nominally infinite gain.Expressions are given for the sensitivity of the (Q-factor and frequency of location of the ‘peak’ to variations in the ratios of the passive elements and to gain. Also the effects on theQ-factor of finite gain and phase shift in the amplifier are observed.The operational amplifiers are assumed to be of infinite input impedance and zero output impedance and to have a gain which is approximated to a first-order lag.

DOI:10.1049/ree.1969.0032

出版商:IERE    

年代:1969

数据来源: IET