DOI:10.1049/ree.1967.0082

出版商:IERE    

年代:1967

数据来源: IET

摘要:

The main theme of this paper is that of designing good maintainability into a product from the viewpoints of (a) basic component reliability, (b) readily accessible test/monitoring points and (c) ready access and speedy changing of components or modules in cases of failure. The coming of colour television, with its greater complexity, emphasizes the need for attention to these points.

DOI:10.1049/ree.1967.0083

出版商:IERE    

年代:1967

数据来源: IET

摘要:

The objective and methods of measurement on linear, timevariant communication channels are discussed with a view of assessing their applicability for the diagnostics of certain unconventional channels of interest to space communication. These may include channels formed during the early, powered phase of the space vehicle flight and during its re-entry into the Earth's atmosphere. No attempt is made here to elucidate the physical phenomena which are responsible for the formation and properties of such channels and the problem of their measurement is approached from the input-output point of view. It is assumed that the channels in question have been rendered semi-transparent through a suitable choice of carrier frequencies, but that the transmitted waveforms are impressed with identifiable channel characteristics, such as the multipath and Doppler spread. It is concluded that due to the uniqueness and complexity of such channels only the most rudimentary measuring methods, leading to the estimates of gross channel parameters, can be contemplated at this time. The need for further research is indicated.

DOI:10.1049/ree.1967.0084

出版商:IERE    

年代:1967

数据来源: IET

摘要:

In this paper the importance of effective communications is stressed. There are three stages in the handover: preparation, transfer and development. While there is still sufficient time to explore the reasons for disagreement between the parties each should be preparing the other to deal with problems which will be urgent later on. The formal transmission of design documents must take into account the mechanics of issuing different versions of the same assembly to different groups of users and coping both with the need for advance information to some clients and historical information to others. Development is the most hectic process. The differing objectives of the principal agents, project, design, inspection and works are described. There are several characteristic features of the manufacturing department which strongly influence this stage of handover.

DOI:10.1049/ree.1967.0085

出版商:IERE    

年代:1967

数据来源: IET

摘要:

Design is seen as a complex activity requiring intellectual effort at several levels. The highest level is what we, rather loosely, call creative and corresponds with the selection (‘invention’) of potential schemes. There follows an analytical activity (‘how does it work?’) and finally a clerical operation (‘how good is it?’) which yields quantitative data on which the acceptability of the scheme is judged. Interactions occur between activities at the several levels until a satisfactory solution is achieved (or hope is given up of ever finding one). Some of the operations, primarily from the lower intellectual levels, may be handled by computer methods but very few applications are known in which the entire design process has been performed by the computer. Typical applications at the present time necessitate constant interplay between man and computer and this requirement for a man-machine partnership raises special problems in hardware and software departments.The paper identifies the roles of man and computer in typical design applications and outlines some of the special hardware, software and system techniques which have been developed. Particular computer-aided design (c.a.d.) topics in circuit design, logic design, placement and conductor layout are discussed. Finally the generality of total systems and the interfaces between the c.a.d. office and other plant activities are considered.

DOI:10.1049/ree.1967.0086

出版商:IERE    

年代:1967

数据来源: IET

DOI:10.1049/ree.1967.0087

出版商:IERE    

年代:1967

数据来源: IET

摘要:

This paper describes a flexible digital data recording and recovery system which will accept information of up to 76 bits per event at a rate variable from some 375 to some 48 × 103bits per second (b/s), and replay at a rate of from 3 × 103to 48 × 103b/s. The total tape storage capacity is some 55 × 107bits. The number of parameters recorded is limited only by the accuracy required and by the total event size (in relation to the maximum number of bits per event), provision is made within the equipment for correlation determination between selected parameters and for the selective examination of recorded data. The tape transport control system permits remote control which facilitates its integration into a computer complex.The system is illustrated by examples of its application to the acquisition of data from nuclear experiments.

DOI:10.1049/ree.1967.0088

出版商:IERE    

年代:1967

数据来源: IET

摘要:

Introduction of some insignificant restrictions into the theory of electromechanical delay lines gives rigorous solutions of great simplicity. These restrictions are: (a) the line shall be described by a two-row two-line matrix; (b) the transducers are represented by equivalent circuits with concentrated elements; (c) the transducers shall be electrically tuned to obtain the widest possible bandwidth; (d) the delay line shall be symmetrical; (e) the losses shall be restricted to the electromechanical transducer resonators, their mechanical terminating resistors and the electrical input and output circuits. The solution of the equations obtained solves an optimization problem and allows, among other things, the determination of the rippleWof the transfer at the band-edge as a function of the normalized attenuation in the middle of the pass-band.

DOI:10.1049/ree.1967.0089

出版商:IERE    

年代:1967

数据来源: IET

摘要:

The logarithmic nature of the voltage-current characteristics of silicon junction diodes is exploited to design an analogue multiplier. Four silicon junction diodes are used in conjunction with a differential operational amplifier in the multiplier circuit. The principle of operation, design considerations and techniques to compensate for temperature effects and unequal diode parameters are discussed. Methods of performing division and generation of special types of functions are outlined. Measurements on an experimental single quadrant multiplier show that an accuracy of multiplication of the order of 1% can be achieved. Long term temperature drift at the output is measured to be 2% per 10 degC change in ambient temperature. The bandwidth of the multiplier is directly dependent on the operational amplifier employed. With a Donner (Model 3400) amplifier, the bandwidth is measured to be about 200 Hz. An attractive feature of the circuit is that it lends itself for miniaturization with the advent of differential operational amplifiers in the integrated circuit form.

DOI:10.1049/ree.1967.0090

出版商:IERE    

年代:1967

数据来源: IET

摘要:

Defect statistics on guided weapons and other equipment clearly indicate that the more unusual components and the ‘special to project’ innovations show the highest failure rates. Electromechanical components are examples and such failures are emphasized in guided weapons as the total running time may be a few hours with only a few minutes in flight.This paper shows that since the design and shape of most electrical/electronic components is primarily to facilitate their functions and ease of production, a large variety of shapes and sizes for different types of components is a major problem in equipment design. It is suggested that improved customer/vendor relations and national standardization of new styles of components might help to ease the situation.

DOI:10.1049/ree.1967.0091

出版商:IERE    

年代:1967

数据来源: IET