The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 15, 1980
Filed:
Nov. 02, 1978
Edwin A Dokus, Winchester, MA (US);
David Banks, South Hamilton, MA (US);
American Optical Corporation, Southbridge, MA (US);
Abstract
An improved control is provided for the tape transport motor of a battery-powered, slow-speed tape recorder typically used for producing magnetic recordings of an ambulatory patient. The recorder's tape transport means is driven by a synchronous AC motor powered from a DC (battery) supply. That DC supply, during normal operation, is voltage regulated to provide desired speed stability. That DC supply is inverted into a square wave DC current in a manner effectively providing a regulated square wave AC at twice the regulated DC voltage. Phase-shifting means connected to the inverter provide a phase-shifted square wave source necessary for the two-phase AC synchronous motor. In an improved mode of control, means are additionally provided for selectively supplying current at full battery voltage, square wave inverted and phase-shifted to the AC synchronous motor in lieu of the regulated supply voltage to provide high torque operation for selected periods of time as during 'start-up' or 'warm-up'.