Adam, Your basic idea is reasonable, couple caveats though. You are gonna have to spin the motor fairly fast, if I remember correctly disk spindle motors ran at about 300rpm. To use the motor as a generator, you are gonna need a reasonable fraction of that to generate any appreciable voltage. Depending on the motors quality and construction. Maybe coupling via a gear stepup system. The second thing to consider, storing power in the cap and then using a linear regulator to drop it down. Any drop on the regulator is wasted power. Not sure what solutions are available, but these you will need to consider. Doug ----- Original Message ----- From: Adam Bryant To: Sent: Monday, November 08, 1999 11:38 PM Subject: Disk drive spindle motors as DC generators. > Per my previous question about using old DC spindle motors as DC > generators for a PIC circuit I came up with a few more questions based on > the fact that these motors originally ran off of 12 volts. > > Theoretically, these motors could generate more than 5 volts if spun fast > enough. How would I efficiently limit the PIC supply to 5 volts? A low > dropout regulator? > > How do I store excess juice generated during faster wind gusts for when > the wind isn't blowing so hard. We tend to have very gusty conditions > around here. The wind can be blowing 25mph one minute and 2 or 3mph the > next. > > Could someone help me out with a basic circuit drawing? I am envisioning > something along the lines of: > > +----|>|-----+-----VREG-----+ > | | | | > Motor Cap | PIC > | | | | > +------------+-------+------+ > > The motor generates DC of whatever voltage when spun, the capacitor > stores it, the diode prevents the capacitor from spinning the motor, > voltage regulator supplies 5v to the PIC. > > As always, apologies for the ASCII art and limited electronics knowledge. > Adam > > > Adam Bryant (age 0x23) > adamdb@juno.com > Parker, CO, USA > Robotics, RC Airplanes, anything using a PIC > > ___________________________________________________________________ > Get the Internet just the way you want it. > Free software, free e-mail, and free Internet access for a month! > Try Juno Web: http://dl.www.juno.com/dynoget/tagj.