Radio-Frequency Autotransformers with Coaxial-Transmission-Line Windings

This paper describes a high-gain phase-sensitive magnetic amplifier which simultaneously possesses the high-gain property of the self-saturating (100 percent positive feedback) amplifiers and the limited circulating current property of the low-gain zero feedback amplifiers. These features are obtained by using feedback windings to obtain the self-saturating large-gain property. However, the feedback windings are arranged so that the feedback is positive only when load current flows and is zero when circulating currents flow. The circuit is analyzed and its various modes of operation are described. The theory is verified with numerous experimental results.