Showing papers in "Journal of the Institution of Electrical Engineers in 1917"

The mathematical treatment of the magnetomotive force of armature windings

Abstract: The paper aims at giving a complete analytical treatment of the magnetomotive force produced by a polyphase armature winding. The fundamental principles and the scope of the investigation are enunciated in Section I. In Section 2 the magnetomotive force of a winding composed of full-pitch coils carrying sinusoidal phase-currents is investigated, and the results are applied to the case of a uniformly distributed winding in Section 3, and to a slotted armature in Section 4. The effect of the coil-span on the distribution of magnetomotive force is discussed in Section 5, and a complete generalization of all the foregoing results for currents of any wave-form is given in Section 6.

Colonial telegraphs and telephones

Abstract: General.—Introductory. British Post Office practice. Appointment of engineers. Working staffs. Sources of supply.Administration.—Small Crown Colonies. Large Crown Colonies. Telegraph Administration. Telephone Administration. Canada, Australia, New Zealand, South Africa. Amalgamation of Railway Telegraphs with Postal Telegraphs. Electric lighting in charge of telegraph engineers.Engineering.—Overhead construction.Pole lines : Crown Colonies and South Africa, Canada, Australia, New Zealand.Pole fittings : Ditto.Line wire : Ditto.Farmers' lines on fences, Canada.Telegraph systems : Crown Colonies, South Africa, Canada, Australia, New Zealand.Telephone systems : Ditto.Lightning dischargers and protectors.