DOI:10.1049/piee.1964.0001

出版商:IEE    

年代:1964

数据来源: IET

DOI:10.1049/piee.1964.0002

出版商:IEE    

年代:1964

数据来源: IET

摘要:

Improvements in computer store cycle and computing times have called for an increase in the rate of transfer of information beween the computer and its peripheral devices.This paper describes a system which can control the simultaneous demands of a number of transferring peripheral devices, to make up for the large differential between the information transfer rates of modern computer stores and existing peripheral devices. The system can control the transfer of information between 64 transferring peripheral devices, where the individual character transfer rate does not exceed 2.5kc/s, and a main store whose cycle time is 6μs. The system has been designed to minimise the amount of buffer storage, between each peripheral device and the main store, without limiting the variety of peripheral operations.The paper also describes how this system has been extended to control a smaller number of simultaneously transferring high-transfer-rate devices, where the combined character rate does not exceed 1.2 Mc/s.The peripheral transfer control works in conjunction with a fixed, or director, programme which enables the peripheral devices to be divided amongst several time-shared programmes.

DOI:10.1049/piee.1964.0003

出版商:IEE    

年代:1964

数据来源: IET

摘要:

From the consideration of a shunt-input/shunt-output type of feedback amplifier, a procedure is developed for synthesising the feedback network so as to realise Bode's ideal loop gain characteristic with specified gain and phase margins and midband open-loop gain. The designed network is basically a T structure with resistors and capacitors only.

DOI:10.1049/piee.1964.0004

出版商:IEE    

年代:1964

数据来源: IET

摘要:

The paper presents the design and performance of a new frequency discriminator for widely deviated low-frequency subcarriers as used in multichannel communication links.A simple theory is developed to evolve a design procedure and to determine the conditions for wideband linearity in the frequency/voltage characteristics of the circuit, and this theory is confirmed experimentally. The use of inductors is avoided in the circuit to eliminate practical problems associated with the use of necessarily large inductors at low subcarrier frequencies, the alignment procedure is simple and straight-forward and the centre frequency of the discriminator can be altered by a single noninteracting control.

DOI:10.1049/piee.1964.0005

出版商:IEE    

年代:1964

数据来源: IET

摘要:

A description is given of an equipment capable of subjecting 1000 resistors automatically and simultaneously to any desired combination of climatic and power loading cycles, and to measure and record resistances at any desired points.The equipment has been used to evaluate 38 batches (27 500 resistors), and a summary of these results is included.

DOI:10.1049/piee.1964.0006

出版商:IEE    

年代:1964

数据来源: IET

摘要:

The paper describes the representation of a junction in circular waveguide between a homogeneous region and one containing an axial rod of circular cross-section. The parameters of an approximate equivalent circuit are obtained in terms of the physical properties of the junction. Experiments are described which show that, for dielectric rods of low relative permittivity, it is reasonable to neglect the junction susceptance. If the relative permeability of the rod is unity, the characteristic-admittance ratio assumes a particularly simple form corresponding to the ratio of the dominant-mode phase-change coefficients on either side of the junction. When the relative permeability of the rod differs from unity, as in the ferrite analogue, the expression for the admittance ratio is more complicated. Results obtained using a digital computer are presented.

DOI:10.1049/piee.1964.0007

出版商:IEE    

年代:1964

数据来源: IET

摘要:

The design, construction and performance of a magnetron that has been developed primarily for heating applications are described. Between 20 and 30kW output power can be obtained, at efficiencies of over 80%, near the theoretical limit. This performance is achieved using a 10-segment double-ring-strapped anode, 2in long, in conjunction with a tungsten-helix cathode. A coil round the anode provides the magnetic field.Some initial development difficulties arose from interfering resonances of the cathode structure, and in oscillating valves, overheating parts of the cathode at high magnetic fields. Chokes and cathode modifications for resonance control are described.Two types of output have been tried: a direct feed to coaxial line, and a probe radiating into waveguide. The second type is found more suitable at higher powers.Performance data are presented for fixed fields and for the electromagnet connected in series with the anode—a mode of operation, which offers some stabilisation of output power against supply-voltage changes.The output of present valves is limited by the anode-dissipation capability and heating of the output window. Further developments are towards improved methods of cooling and the use of lower-loss window materials. The possibilities for higher-power valves developed along similar lines are considered briefly.

DOI:10.1049/piee.1964.0008

出版商:IEE    

年代:1964

数据来源: IET

摘要:

A new co-ordinate transformation describing concentric toroids enables the potential distribution of a toroidal concentric space-charge-limited diode to be calculated. The results are represented approximately by an analytic function that allows the calculation of perveance, current and other characteristics of a hollow-beam electron gun. It is shown that previous calculations are in error. The shapes of the focusing electrodes for a hollow-beam gun are determined by an electrolytic-tank analogue. It is thus possible to design a gun for thick hollow beams. It is shown that, for thick beams, the correct focusing electrodes for a hollow-beam gun are very different from those of a strip-beam gun. It is, however, possible, within a certain range of the relevant parameters, to use the Langmuir-Blodgett potentials of a cylindrical space-charge-limited diode in order to determine the ‘toroidal’ focusing electrodes in the electrolytic tank for the design of a hollow-beam gun.The potential distribution for a charge-free toroidal diode is measured and calculated. The toroidal diode theory includes the theory of cylindrical and spherical diodes as special cases. The results give us a method by which we can introduce a further correction, so that a hollow-beam gun for very thick beams can be designed. An experimental gun confirms these calculations.

DOI:10.1049/piee.1964.0009

出版商:IEE    

年代:1964

数据来源: IET

摘要:

The problem of obtaining an analytical expression for the tunnel-diode static characteristic is best approached using essentially a curve-matching technique. Two types of expressions are possible:(a) a simple expression (one or two terms only) which can be used in analytical studies(b) a complex expression suitable for computer manipulation.The error can be held to ±10% of the peak current using the type (a) approach, and details are given. Greater accuracy is possible with the type (b) approach, and examples are given in which a ±2% error is obtained using a ninth-order polynomial for a gallium arsenide diode; an error of ±5% is obtained using a seventh-order polynomial for a germanium diode.Using a reduction method and the type (b) expression, it is shown that representation of the static characteristics up to the valley voltage is possible using a quartic expression, the error being ±10%. This result is important in view of the number of attempts which have been made to achieve a match with a low-order polynomial. The quartic expression can be derived directly using Lagrange's interpolation formula.The error from the type (a) approach is small, and it is expected that this approach will be entirely adequate for the solution of engineering problems.

DOI:10.1049/piee.1964.0010

出版商:IEE    

年代:1964

数据来源: IET