[sdiy] motors (was Embedded micros)

[Scott Gravenhorst]

Very true.  AFAIK, only motors with permanent magnets
for the field will generate current independantly.

Many moons ago, I worked for Digital Equipment Corp.
I have 2 DC motors from a DEC line printer that were
used to move the ribbon.  I used to play with these
connected together, turning one would generate enough
current to cause the other to turn at almost the same
rate.  The puzzling part was the number of other techs
that were amazed by this and didn't know why it worked.

sasami at blaze.net.au (Ken Stone) wrote:
>The easiest way is to turn the shaft, note the physical resistance, then
>short the output and try again. It should be a lot heavier to turn.
>Generally motors with magnets in them will work, but those without will not.
>(unless you plan to endergise the field coil separately, then they will
>too.) Stick to DC motors of the brushed type. Stepper motors will also work,
>though you will probably get AC out of them.
>
>>>Actually, I've been toying with a "mechanical" module the last few days.  I
>>>have a motor from an old Laser Disc Player that conveniently works as a DC
>>>generator.  It has a 3.5" diameter wheel attached to the top that I'm
>>>planning to weight with lead-free solder for a little more inertia.
>>
>>I've been wanting to do something like this for a while now.  Anybody 
>>know if there's an easy way to tell if a particular DC motor will 
>>also work as a generator?  How about AC motors?  And I mean besides 
>>using a voltmeter (like if I'm rummaging through trash or in a 
>>surplus or junk store).  Is there any particular kind of motor which 
>>does/does not function both ways?
>>
>>I haven't messed much with DC ones, but I know a lot of the AC motors 
>>I've tried will not generate.  I wanted to take an old turntable of 
>>mine and mount a bunch of AC motors on it so the turntable would turn 
>>their shafts.  By varying the turning speed of the turntable and 
>>position of the motors, I could get them to emit tones in and out of 
>>harmony with each other.  I think it would make a nice sine wave 
>>generator.  Is this feasable with any existing AC motors?
>>
>>-Tavys
>>
>>
>_______________________________________________________________________
>Ken Stone   sasami at blaze.net.au  
>Modular Synth <http://www.blaze.net.au/~sasami/synth/>
>Catgirl Paradise <http://www.anime.net/~kens/>
>Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>
>

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