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:
Jan. 05, 1999
Filed:
Mar. 05, 1997
John T Rotunda, Bothell, WA (US);
Lester A Hass, Duvall, WA (US);
Victor Pipinich, Seattle, WA (US);
Quinton Instrument Company, Bothell, WA (US);
Abstract
A variable speed AC motor control drive system for use in devices such as treadmills and including a module to sense the voltage of the line voltage provided to the system and adjusting the pulse width modulated signals provided to the AC motor in response thereto as well as providing a module for sensing the load placed on the AC motor by monitoring the bus voltage of the system and. providing a signal representative of the load such that the duty cycles of the pulse width modulated signals are varied in accordance with the line voltage of the system and the load on the AC motor to maintain the desired motor speed.