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

Image Number 4 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
Method and system for video parameter analysis and transmission
Method and system for evaluating/analyzing patent portfolio using patent priority approach
Inductive antenna coupling
Method and apparatus for transmitting and receiving extension information of component carrier in wireless communication system
Aperture stop
Microfluidic cartridge and method of using same
  Randomly Featured Patents
Video processing apparatus, video processing method and DVD video apparatus
Set of golf clubs
Tone arm return systems for record player with eccentric spindle hole immunity
Liquid crystal display with transparent heating layer comprising carbon nanotube structure
Servomotor controller
Process for preparing alkyl(methoxymethyl)trimethylsilanylmethylamines
Standby generator integration system
6,7-dihydro-5H-pyrazolo[1,2a]pyrazol-1-ones which control inflammatory cytokines
Gas turbine electric powerplant
ID registration method for tire pressure sensor, ID registration apparatus, ID registration tool for tire pressure monitoring system, and tire with air pressure sensor