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
Porous objects having immobilized encapsulated biomolecules
Methods and devices for multiple-mode radio frequency synthesizers
Graphical communication user interface with graphical position user input mechanism for selecting a display image
Sublingual coated tablet of fentanyl
Microwavable bag
Method and system for monitoring and treating hemodynamic parameters
  Randomly Featured Patents
Short-vowel intrinsic-sound learning system
Sense and hold amplifier
Light source module for collecting reflective beam from light source
Stopper with integral spraying device
Patient support system for medical transport vehicles
System and method for improving DSL performance
Cyclic peptide and method of use for inducing an immunological response to hepatitis B virus
Earring adapter for telephone
Vented multi-wok cooking range
Valve actuating device and fuel injector using same