Resources Contact Us Home
Phase difference detection device and method for a position detector

Image Number 11 for United States Patent #6885310.

Two A.C. output signals amplitude-modulated in accordance with two function values (sine and cosine) differing from each other in correspondence to a position-to-be-detected are received from a position sensor such as a resolver. By performing an addition or subtraction between a signal derived by shifting the electric phase of one of the received A.C. output signals by a predetermined angle, and the other received signal, two electric A.C. signals (sin(.omega.t.+-.d+.theta.), sin((.omega.t.+-.d-.theta.)) are electrically synthesized which have electric phase angles (.theta.) corresponding to the position-to-be-detected and are phase-shifted in opposite directions. ".+-.d" here represents phase variation error caused by factors, other than the position-to-be-detected, such as temperature change. In the synthesized two signals, the phase variation errors (.+-.d) appear in the same direction, while the phase differences (.theta.) corresponding to the position are shifted in opposite, positive and negative, directions. Thus, by measuring the respective phase shift amounts (.+-.d+.theta., .+-.d-.theta.) and performing appropriate operation, it is allowed to cancel out or extract the error (.+-.d) so that an accurate phase difference (.theta.) can be detected. Position detection data indicative of the detected phase difference (.theta.) is converted into a pulse-width-modulated signal and transmitted in the pulse-width-modulated form.

  Recently Added Patents
Gas flow indicator
Liquid formulations of carboxamide arthropodicides
Data processing apparatus and data processing method for reducing an uneven color made up of two or more ink colors
Using sets of OTDR receive fibers with different lengths of marker events to verify optical fiber connectivity
Electrode binder composition, electrode slurry, electrode, and electrical storage device
Semiconductor apparatus
Pet carrier
  Randomly Featured Patents
Chamfer cutting tool
Xanthomegnin, a known compound, is an antiparasitic agent
Lateral bipolar transistor and method of making the same
Diamond anode
Liquid crystal display device
Plasma ion nitrided stainless steel press plates and applications for same
Analytical element for the analysis of whole blood
Wear screen plate and method of manufacture thereof
Cover for garage-opener truck
Electronic device for controlling a printing machine