Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
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
Digital broadcasting system and method of processing data
Electronic device with a screen
Lubricant coating device and image forming apparatus
Packaging article
Playback device for stereoscopic viewing, integrated circuit, and program
Scalable architecture for rank order filtering
Visual processing apparatus and visual processing method
  Randomly Featured Patents
Control elements for an electrical device
Switch actuating mechanism for two sequentially activated switches
Indexing conveyor for workpiece blanks
Process and gravity feed mixer for mixing bulk materials in a container
Antiprotozoal cyclic tetrapeptides
Address range extension for a modular computer
Carburizing method
Developing unit with a housing assembly
Charge generation layers comprising at least one titanate and photoconductors including the same
Stable, hydrogen peroxide-containing bleaching compositions