Measurement of Variation in Rotational Speed

Abstract

This paper describes measurement of speed variation of motors to analyse the distortion of the playbacked pictures when applied to taperecorders, VTR, facsimiles and so on.
Standard pulses are recorded on a drum driven by a motor and simultaneously the recorded pulses are read after a certain angle rotation. Then this delayed time between the recorded pulse and the read one informs the speed variotion of the motor.
This paper descusses the fundamental relation between the variation of the delayed time and the speed variation. According to the experimens, the speed variation which corresponds to the number of poles of the motor was remarkable. The optimum driving and controlling system of the equipment is analytically inspected and designed by the aid of the measurement of the speed variation.