Electricity: motor control systems inventions 01/09

20090028532 - Control device for driving a brushless dc motor: A delta type inverter is used in conjunction with a closed-loop motor controller to provide a control device for driving a three phase brushless direct current motor. The delta inverter has one-half of the solid state switching devices and diodes required by conventional bridge type inventers, thereby improved reliability, and... Agent: General Motors Corporation Legal Staff

20090022483 - Device and method for driving a single phase motor: A driving device is provided for controlling the rotation of a motor. The driving device comprises an input module, a comparing module and a processing module. The input module includes a voltage generating unit and a voltage adjusting unit to generate a comparing voltage. The voltage generating unit generates a... Agent: Joe Mckinney Muncy

20090003806 - Method and circuit for controlling rotation speed of computer fan: An exemplary method for controlling rotation speed of a computer fan includes: judging the type of a fan by comparing two rotation speeds detected before and after changing a duty cycle of a PWM signal respectively; controlling the computer fan as a 4-pin fan the PWM signals if the rotation... Agent: PCe Industry, Inc. Att. Cheng-ju Chiang