Electric motor control apparatus and method
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Feb 16, 1993
Grant Date -
N/A
app pub date -
May 6, 1991
filing date -
May 6, 1991
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
An electric induction motor is connected by a switch means to a source of three-phase alternating electricity. The speed of the motor is determined by detecting when the source voltage a zero crossing and thereafter sensing the polarity of the back emf voltage induced in each winding of the motor when the switch means is non-conductive. After several zero crossings a set of polarity samples has been produced from each winding. The motor speed is determined by detected the occurrence of a predefined relationship among samples in each set. For example, the speed is in the range of fifty to about thirty-eight percent of full synchronous speed when three consecutive samples from one winding all have the same polarity. The occurrence of the predefined relationship among back emf polarity samples can be used to control the braking of the motor.
First Claim
Family
International Classification(s)
- No Non-US Classification to display
Cited Art Landscape
Patent Citation Ranking
- No Patent Citation Ranking to display
Advertisement
Advertisement
Advertisement
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully