| 20080265833 | Driving level control structure eliminating electric noise from motor - A driving level control structure eliminating electric noise from motor includes a drive control unit, a sensing unit, a setting unit, a first comparing unit, and a frequency control unit. The first comparing unit generates a first discriminating signal based on a reference level signal provided by the sensing unit and a preset level signal provided by the setting unit. The frequency control unit generates a second discriminating signal based on the first discriminating signal. The second discriminating signal is set to a specific frequency fallen out of a human ear perceptible frequency range before being sent to the drive control unit for controlling a motor coil unit to on or off as a current limiting operation, so that electric noise from a motor during the current limiting operation thereof is eliminated. | 10-30-2008 |
