Electricity: motive power systems – Positional servo systems – With particular 'error-detecting' means
Reexamination Certificate
2001-03-29
2002-10-29
Nappi, Robert E. (Department: 2837)
Electricity: motive power systems
Positional servo systems
With particular 'error-detecting' means
C318S605000, C341S112000, C310S168000
Reexamination Certificate
active
06472841
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to resolvers, and more particularly, to an improved resolver with redundant excitation windings.
BACKGROUND ART
Certain specific applications require a shaft position, feedback device which is redundant for safety purposes, but must be inexpensive in order to be feasible for the application. Typically, two independent feedback devices are needed to achieve the redundancy required for the application. In order to minimize cost, it is desirable to wind a single resolver stator lamination stack with two excitation windings and two sets of output windings which are coupled through a single rotor rather than providing separate stator lamination stacks and separate rotor pieces. Using conventional winding techniques with two resolver windings on a single core, excited independently, results in cross coupling between the redundant windings preventing them from being totally independent from one another. This results in a distorted wave form from the output windings which causes the decoded feedback information to be inaccurate.
SUMMARY OF THE INVENTION
An object of this invention is the provision of a resolver with redundant windings that minimizes the cross coupling between the windings while, at the same time, maintaining symmetrical output signals.
Briefly, this invention contemplates the provision of a resolver with redundant excitation windings in which only a single excitation winding is energized externally at a given time. Cross coupling from the externally energized winding induces a voltage in the other excitation winding. A control circuit monitors the voltage on the redundant winding and switches the excitation to the redundant winding in the event of a failure of the externally excited winding or its excitation source.
REFERENCES:
patent: 3849774 (1974-11-01), Barth
patent: 4795954 (1989-01-01), Sakurai et al.
patent: 5644224 (1997-07-01), Howard
patent: 5708344 (1998-01-01), Hayashi et al.
patent: 5760562 (1998-06-01), Woodland et al.
patent: 6084376 (2000-07-01), Piedl et al.
Barani Moe K.
Flanary Ron
Piedl Martin
Aspen Motion Technologies, Inc.
Duda Rina I.
Nappi Robert E.
Quarles & Brady LLP
LandOfFree
Low cost redundant resolver system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Low cost redundant resolver system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low cost redundant resolver system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2998915