ALEXANDRIA, Va., June 17 -- United States Patent no. 12,316,251, issued on May 27, was assigned to HORSTMANN SYSTEMS Corp. (Pasadena, Calif.).
"Variable-speed drive for single-phase asynchronous motors" was invented by Manfred Horstmann (Pasadena, Calif.).
According to the abstract* released by the U.S. Patent & Trademark Office: "A frequency converter circuit is disclosed for controlling the speed of a single-phase asynchronous motor wherein the controlled speed keeps the slip between the speed of a driving magnetic field and a speed of a motor rotor as small as possible. Voltage and frequency are provided by the frequency converter circuit wherein a current is provided using the characteristics of the motor and its load mechanically con...