Patents Assigned to Ampson Technology. INC
  • Patent number: 7012388
    Abstract: A constant-current driving method and a driving circuit for a DC motor are provided. A DC motor is often used for a DC fan. For a DC motor having two magnetic coils, the constant-current driving method is implemented by employing two control voltage signals to respectively control two semiconductor switches that are respectively connected to the two coils. One terminal of each coil is connected to a same high DC voltage, and one terminal of each semiconductor switch is connected to a same low DC voltage. The two semiconductor switches do not turn on at the same time. When each semiconductor switch is turned on, the current flowing through the coil connected to the switch eventually approaches and remains at a constant value. The constant-current driving method is especially suitable for producing low-rotation-speed and low-current DC motors.
    Type: Grant
    Filed: June 7, 2004
    Date of Patent: March 14, 2006
    Assignee: Ampson Technology. INC
    Inventors: Yi-Pin Lin, Ray Ku