Abstract :
Starting with the principle that a coil (or capacity) rotating in a single phase alternating magnetic (or electric) field, may be regarded as producing a magnetic (or electric) field rotating with double frequency, a number of frequency doublers and multipliers of magnetic and electric nature are described. Under this heading, the reflection or Goldschmidt alternator is considered. A typical mercury arc frequency doubler is treated. The use of electrolytic rectifier cells in increasing frequency is discussed, and a number of useful arrangements of this type shown. Frequency multiplication by the use of the arc is also handled. A detailed description of a number of frequency changers depending on the nature of the magnetising force-induction curve of iron follows. The application of the results to the field of radio telephony, and the possibility of adequate trigger control of the outgoing energy by ordinary microphones is considered.