Principles and practice of electrical engineering (1914)
Gray, Alexander, 1882-1921 · New York [etc.] McGraw-Hill Book Company, inc. · leaf 221
B—Scale when the frequency is 100 cycles. C—External appearance.Fig. 215.—Vibrating reed type of frequency meter. … Fig. 216.—Average value of an alternating electromotive force Art. 230] ALTERNATING VOLTAGES AND CURRENTS 197 will be set in violent vibration. The reeds have their free endswhitened and appear as white bands when vibrating. The ex-ternal appearance of such an instrument is shown in diagram C.229.…
Electrical engineering
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer02inte-207-100.webp)
