Conversion of a Motor Generator into a Low Noise Power Amplifier
H. S. Sommers, P. R. Weiss, W. Halpern · Review of Scientific Instruments · 1949
The noise output of motor-generator sets is so large as to impair their use in precision control work. This paper describes a method for reducing this noise by incorporating a motor generator in an electronic feed-back circuit. The method is based on the use of a high frequency output channel in parallel with the generator to permit cancellation of the higher harmonics of the noise. Design, construction, and performance of an amplifier based on a ½-kw M-G set are described. The noise output of this unit is ⅕ percent of the normal noise of the generator.