EXTRACTS FROM PREFACE.
“The present work is purposely confined to continuous current generators. The calculations and data being expressed in inch measures; but the author has adopted throughout the decimal subdivision of the inch; small lengths being in mils, and small areas of cross-section in sq. mils, or, sometimes, also, in circular mils.”
CONTENTS OF CHAPTERS.
1. Dynamo Design as an Art.
2. Magnetic Data and Calculations. Causes of waste of Power. Coefficients of Dispersion. Calculation of Dispersion. Determination of exciting ampere-turns. Example of Calculation.
3. Copper Calculations. Weight of Copper Wire. Electrical resistance of Copper, in cube, strip, rods, etc. Space-factors. Coil Windings; Ends; Insulation; Ventilating; Heating.
4. Insulating Materials and Their Properties. A list of materials, including “Armalac,” “Vitrite,” “Petrifite,” “Micanite,” “Vulcabeston,” “Stabilite,” “Megohmite,” etc. With tables.
5. Armature Winding Schemes. Lap Windings, Ring Windings, Wave Windings, Series Ring-Windings, Winding Formulæ. Number of circuits. Equalizing connections. Colored plates.
6. Estimation of Losses, Heating and Pressure-drop. Copper Losses, Iron Losses, Excitation Losses, Commutator Losses, Losses through sparking. Friction and Windage Losses. Secondary Copper Losses.
7. The Design of Continuous Current Dynamos. Working Constants and Trial Values; Flux-densities; Length of Air-gap; Number of Poles; Current Densities; Number of Armature Conductors; Number of Commutator Segments; Size of Armature (Steinmetz coefficient); Assignment of Losses of Energy; Centrifugal Forces; Calculation of Binding Wires; Other procedure in design. Criteria of a good design. Specific utilization of material.