motor that works as generator

[johnny]

i pulled a cd rom apart and there are 2 dc motors thsat work as generators. the part number on the motor is MDN3BL4CHQ out of a off brand desk top.

[Ian S C]

Hi Johnny, most motors will work as generators, or alternators. Most of the motors used in CD players, and VHS vidio tape machines are actually 3 phase AC, and can be used that way, or with diodes to produce DC, if the motor has brushes it will generate DC current. Possibly one of the motors is the little DC motor that opens, and shuts the draw, the other one drives the scanning head, and I think that may be a stepper motor, it will have a long shaft on it with a screw thread on it. Ian S C

[johnny]

one of the motors moves the laser the other opens and closes tray

[Ian S C]

Then there is a third motor that spins the disc, its a little flat one, the coils are fixed and the magnet spins around outside the coils, it's three phase AC, controled electronicly, it could be converted into a three phase alternator, although the bigger ones of this type found in VHS recorders show more promise. Ian S C

[theropod2]

Then there is a third motor that spins the disc, its a little flat one, the coils are fixed and the magnet spins around outside the coils, it's three phase AC, controled electronicly, it could be converted into a three phase alternator, although the bigger ones of this type found in VHS recorders show more promise. Ian S C

If one constructs a matching set of iron discs of the same size as the coils of one of those motors and builds a tiny dual disc axial flux alternator one can harvest power very easily. That 3 phase, when rectified, makes some smooth DC, and with the right rare earth magnets the little alternator could be quite efficient. Perhaps the best way to drive one of these would be to build the crank with the inner disc fixed and float the coils with an attaching outer disc. The axial flux alternator can be seen here.

[youtube]http://www.youtube.com/watch?v=_jaIHJUf110[/youtube]

R

[Ian S C]

theropod2, you can strip and rewind these motors to run single phase, not quite so efficient, but a whole lot less complicated, you can put on a bit more wire on most of the motors, theres quite a bit on the net about brushless motors, these things can be moddedto power model aeroplanes, Then again its some times better to get into them and take out the little ball races, and not worry about the rest of it. Ian S C