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. 27, 1982
Filed:
Jul. 03, 1980
Applicant:
Inventors:
Abbott W Lahti, Cambridge, MA (US);
Stephen R Russell, Acton, MA (US);
Assignee:
Power Systems, Inc., Cambridge, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318 51 ; 318 67 ; 318 87 ; 318 91 ; 318107 ; 318108 ; 318109 ; 318110 ; 104300 ; 104301 ; 10302 ;
Abstract
A system for simultaneously and independently controlling a plurality of electric motors from a number of dispersed stations. The system operates by transmission of duty cycle modulated selected frequencies superimposed on a DC track voltage on a common power line servicing the motors. The modulation is variable and determines the speed of the motors. Transmitters are portable and designed removably to plug into a common signal transmission cable anywhere along its length without interaction. Receivers, each tuned to a specific frequency and associated with and controlling a motor, are coupled to the common power line.