DOI:10.1049/ree.1984.0089

出版商:IERE    

年代:1984

数据来源: IET

DOI:10.1049/ree.1984.0090

出版商:IERE    

年代:1984

数据来源: IET

DOI:10.1049/ree.1984.0096

出版商:IERE    

年代:1984

数据来源: IET

摘要:

By adapting the forward converter range of switching regulators to include an additional current-controlled feedback loop, derived from either the secondary or primary power circuit, an improvement in the closed-loop performance of the switching regulator can be obtained.The basic analysis work examines the simple single-ended forward converter, with d.c. plus a.c. current control, derived from the secondary power circuit. An additional fixed voltage ramp is also included in the control loop to provide ‘feedforward’ compensation for input voltage disturbances, and also to extend the maximum duty cycle from 50% up to 100%.Using this circuit configuration a simple small signal equivalent circuit for the current-controlled switching regulator can be obtained, enabling the performance of practical designs to be predicted.Practical implementation of the current mode control technique using a standard large-scale integrated circuit together with a number of applications is also given.

DOI:10.1049/ree.1984.0097

出版商:IERE    

年代:1984

数据来源: IET

摘要:

The paper describes a comprehensive evaluation programme being carried out on optical fibre transmission systems, both in a field environment and also under controlled conditions in the laboratory. The work is providing detailed information on the performance of optical fibre systems from a number of commercial sources, in particular by monitoring the overall error performance and by measuring variations of parameters incorporated in the optical power budget. A data logging arrangement, which collects information from operational systems, and the laboratory test schedule are described. An overview of the results obtained to date is given, which concludes by validating the integrity of optical systems design.

DOI:10.1049/ree.1984.0098

出版商:IERE    

年代:1984

数据来源: IET

摘要:

The use of six-step drives for two-phase induction motors supplied from controlled d.c.-a.c. inverters promises a new lease of life for a.c. machines in position control applications. Unfortunately the steady-state static torque produced when both windings are simultaneously controlled by six-step waveforms in quadrature is reduced from that predicted by a fundamental analysis due to the presence of third harmonic in the waveform. There is also a significant oscillatory component of torque present with a frequency of four times line frequency. Although these effects have been observed in the past, no attempt has been made previously to provide a coherent analytical explanation. This paper presents such an explanation using a Fourier analysis in conjunction with the generally accepted motor model.

DOI:10.1049/ree.1984.0099

出版商:IERE    

年代:1984

数据来源: IET

摘要:

This paper presents the basic concepts in testing, beginning with fault-models, and summarizes the major contributions to the design of testable logic. It identifies some of the current problems in v.l.s.i. testing and testability which need further investigation.

DOI:10.1049/ree.1984.0100

出版商:IERE    

年代:1984

数据来源: IET

摘要:

The European Telecommunications Administrations are planning to offer Business Satellite Services from the beginning of 1985. Designed under the auspices of EUTELSAT, the Satellite Multiservice System (SMS) operates in the 14/12.5 GHz bands and will use two satellites: the European Communications Satellite (ECS), and capacity leased on the French domestic satellite, Telecom 1. This paper describes the ECS SMS and in particular the Single Channel Per Carrier (SCPC) access system. This system operates over a range of data rates from 64 kbit/s to 2 Mbit/s and incorporates a number of novel features including satellite-link encryption, the use of soft-decision error correction, and full support of terrestrial interface standards.

DOI:10.1049/ree.1984.0101

出版商:IERE    

年代:1984

数据来源: IET