Patent ID: 7863849
Filing Date: 2011-01-04
Classification: H02P

Abstract:
1. A driver circuit for powering a fan, the driver circuit comprising: a first circuit having an input configured to receive successive numeric values at a first rate, each of the successive numeric values indicative of a desired present rotational speed of the fan, the first circuit further having an output, and further configured to upsample the successive numeric values at a second rate higher than the first rate, and provide successive interpolated numeric values based on the upsampled successive numeric values; a digital modulator configured to receive the successive interpolated numeric values from the output of the first circuit, and further configured to generate a corresponding pulse for each of the successive interpolated numeric values, to obtain a series of successive pulses; and a filter configured to generate a linear control voltage based on the series of successive pulses, wherein the filter is further configured to provide the linear control voltage to the fan for powering the fan, wherein in powering the fan using the linear control voltage, a present rotational speed of the fan corresponds to the desired present rotational speed of the fan indicated by the successive numeric values.