Patent ID: 7231139

Claim:
A motor controller system for reducing fan noise, the system comprising: a plurality of transistors coupled in parallel forming a first transistor segment; a plurality of transistors coupled in parallel forming a second transistor segment; a first fan coil coupled to said first transistor segment on a first end and coupled to a supply voltage of a second end; a second fan coil coupled to said second transistor segment on a first end and coupled to said supply voltage of a second end; a first sequencing logic section coupled to each of said transistors in said first transistor segment, wherein said first sequencing logic section sequentially activates and deactivates at least some of said transistors in said first segment one at a time; a second sequencing logic section coupled to each of said transistors in said second transistor segment, wherein said second sequencing logic section sequentially actives and deactivates at least some of said transistors in said second segment one at a time; and wherein a rise time coil output current and a fall time coil output current of said first fan coil and said second fan coil approximates a linear slope of a straight line and are controlled so as to minimize abrupt changes.