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Radio and Electronic Engineer

Issue 9 • Date September 1972

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Displaying Results 1 - 8 of 8
  • Straws in the Wind

    Page(s): 389 - 390
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (111 KB)  

    First Page of the Article
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  • An automatic biochemical analyser

    Page(s): 391 - 402
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (2438 KB)  

    A machine for the automatic analysis of human blood and other body fluids is described. Brief reference is made to the associated biochemistry. The problems of measurement of sample optical density and the control of sample temperature, are discussed, and the considerations leading to the choice of photo-cells for the analysers are considered. The analysing equipment and the means of achieving positive identification of samples are described. The requirements for controlling the machine are discussed and the application of computer-control to the machine and the logging of output data is described. View full abstract»

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  • Seeing in the dark

    Page(s): 403 - 408
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1961 KB)  

    A survey of the current state-of-the-art in night vision technology is presented, including both direct vision and low light-level television systems. Possible developments in thermal imaging techniques are discussed. View full abstract»

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  • Design of active distributed RC-filters using exponential lines

    Page(s): 409 - 415
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (601 KB)  

    New active distributed RC-structures utilizing exponential RC-lines and operational amplifiers are proposed for realizing band-pass transfer functions and transfer functions having both a pair of complex poles and a pair of complex zeros. It is shown that the magnitude of the amplifier gain for a given pole Q decreases with increasing taper. In the case of the structures realizing both complex poles and zeros, it is shown that the sensitivity with respect to the gain of the pole determining amplifier is considerably lower than that of the structure previously proposed by Ghausi and Bello. View full abstract»

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  • A formal method for designing sequential circuits from synchronous flip-flops such as the J-K type using a hybrid synchronous-asynchronous technique

    Page(s): 416 - 418
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (284 KB)  

    A formal method is presented which simplifies the realization of many counter sequences in asynchronous form from synchronous flip-flops such as the J-K or D type, without requiring the use of preset or clear connexions to establish the sequence. The method is demonstrated by using the procedure to obtain asynchronous circuits in terms of J-K flip-flops for counters operating in the 8-4-2-1 and 5-4-2-1 b.c.d. codes. Though circuits for these sequences are well known the design procedure is of educational interest and offers alternative circuits for the sequences. The procedure is equally applicable to the realization of many other sequences. View full abstract»

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  • A pseudo-random pulse train generator with controllable rate for modelling of audiometric systems

    Page(s): 419 - 424
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (569 KB)  

    Design details are given of a pseudo-random pulse train generator. The generator produces a sequence of `0¿ and `1¿ pulses which occur at uniform time intervals, and with a controllable average rate of `0¿s to `1¿s, but in which the detailed distribution of `0¿s and `1¿s is essentially random. The system is such that the output pattern can be repeated. The instrument has been developed to simulate the behaviour of a human listener's response to sound in the region of the auditory threshold but may find applications in other simulations employing Monte Carlo methods, etc. The system is easily constructed and by using modern integrated circuits only a small number of packages is required. View full abstract»

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  • Statistical Stability in spectrum analysis

    Page(s): 425 - 429
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (594 KB)  

    Some very simple results which are of use in designing the smoothing system for a digital spectrum analyser, to reduce fluctuations due to the random nature of the envelope of the output of a narrow-band filter are deduced. The `signal/noise ratio¿, defined on a mean square basis, of each observation of envelope-squared is unity. The smoothing schemes operate by averaging several observations of envelope-squared, taken at different times or at different frequencies. The discussion shows the relative insensitivity of the result to fine details of the averaging system. View full abstract»

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  • Cascade synthesis of driving point functions using non-uniform RC transmission lines

    Page(s): 430 - 432
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (325 KB)  

    Necessary and sufficient conditions, as well as a synthesis procedure, for realizing a class of driving point functions as a cascade of non-uniform RC transmission lines, are presented. By using known transformations, the results may also be applied to other types of lines, such as lossless lines. View full abstract»

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