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:
Dec. 09, 2014
Filed:
Nov. 19, 2012
Nidec Motor Corporation, St. Louis, MO (US);
Thomas J. Sheahan, Cary, IL (US);
Nidec Motor Corporation, St. Louis, MO (US);
Abstract
A motor controller for an electric motor having a stator and a rotor. The motor controller includes a power input for receiving AC power from a power source; a control input for receiving a control signal from a control; and circuitry for switching power from the power source to the electric motor in response to the control signal. The circuitry is operable to: apply a driving waveform to the stator to cause rotation of the rotor; remove the driving waveform from the stator to cause the rotor to coast and eventually stop; apply a stop detection waveform to the stator while the rotor is coasting, wherein the stop detection waveform induces a waveform on the rotor which in turn induces a waveform back to the stator while the rotor is rotating; and monitor the stator to detect a characteristic of the waveform induced back to the stator to detect when the rotor has substantially stopped rotating.