International Journal of Electrical Engineering & Education

The advantages to both the visitor and the hosts, of sabbatical leave in another country are discussed, and practical advice is offered to anyone contemplating such leave.

This paper outlines the syllabus for two courses in reliability, an extended course and a minimum-length introductory unit. The courses are suitable for inclusion in undergraduate or master's degrees. Prerequisites are discussed. Texbooks and sources of course material are reviewed.

The construction and use of an electromechanical laboratory control experiment is described. The system, which involves a steel ball rolling on a pivoted beam, presents a mechanically simple system which is nevertheless an illuminating exercise in feedback control.

A system for the rapid and economical production of small quantities of precision masks for photolithography is outlined. The techniques described are especially suited to the wide range of device designs encountered in the small research or teaching laboratory.

Torques in electrical machines are developed largely by iron parts rather than conductors. Simple apparatus has been developed to demonstrate the mechanism of torque production. Analyses in terms of iron surface forces, of changes in coil inductances and of hypothetical air gap conductors are contrasted and compared with measured results.

In view of the counter rotating field theory, can a single phase stator winding be used to drive two rotors simultaneously at different speeds in opposite directions, and if so how does the machine perform? The paper puts forward some experimental and theoretical answers to these questions.

This paper describes the principles and fabrication details of a digital proportional position controller using a synchro resolver as position transducer. The digital controller can be readily attached to existing analog position servo demonstration units available in educational laboratories.

A very simple and elegant proof of Thévenin and Norton's theorem is given.

Two assumptions underlie circuit theory: infinite speed of propagation of force and existence at all times of equilibrium in matter. The theory is therefore essentially of static states. Voltages across all circuit components, including inductors, transformers, generators and others, are differences in potential, traceable to Coulomb forces and obeying Poisson's equation.