Resources Contact Us Home
Method of controlling the speed of an electric motor

Image Number 5 for United States Patent #7777442.

A method of controlling the speed of an electric motor, said method being a digital method designed to control the speed of an induction motor that is powered by a triac device to a preset speed, in which the speed of the motor is measured and a digital numerical value representative of the mathematical first derivative of motor speed is calculated. A determination is made of the digital numerical value of the motor speed first derivative relative to a range, or band, of values. An error signal also is computed that is proportional to the error between the measured current motor speed and the preset speed and a determination is made of the digital numerical value of this error signal relative to a range, or band, of values that includes a value corresponding to that of the motor operating at the preset speed. If the value of each of the two signals is within its respective band, then the two numerical values are added to produce a total error signal whose value is then converted to a signal to a signal to correct the triac triggering angle to that needed to obtain the preset motor speed.

  Recently Added Patents
Cartridge for separating analyte from mixture, comprising dispensing and receiving chambers and insert
Wireless communication system, associated methods and data structures
User-initiated quality of service modification in a mobile device
Image capture apparatus and program
Early kill removal graphics processing system and method
Sublingual coated tablet of fentanyl
Application authentication system and method
  Randomly Featured Patents
Amorphous polymeric polyaxial initiators and compliant crystalline copolymers therefrom
Photomask and exposure method
Single chip microcomputer having unauthorized memory space access protection
Sports decoration for an automotive wheel
Chicken breast slicing method and apparatus
Frozen dessert pop
Unit for the production of structured textile velour needle-bonded fabric webs
System, method, and computer program product for identifying objects as at least potentially unwanted based on strings of symbols
Method and apparatus for determining a deviation of an actual shape from a desired shape of an optical surface
Method for flattening the combustion zone in an in situ oil shale retort by the addition of fuel