We had a power outage here yesterday for a few hours. We put in a new
radio phone system a month or so ago, and it went down with the
power. Nothing worked here - except my little experiment, which is
battery operated. I took off the scope probes and hooked up a couple
voltmeters and was back in business with the aid of a book light
attached to my Carhartt's bib jeans! 8^) I was able to look at the
voltage drops across a wide range of rpms, and there was not much
difference. Max was maybe 4 V across the motor total. That was
uncertain. I was surprised to see how wacko it made the digital
voltmeters. The scope signal looks fairly smooth and narrow-ranged.
Since the motor is a bit strange I decided today to do a quick test
for conservation of angular momentum. I remounted the steel bearing
motor vertically for the test, and spun it up with a Dremel tool, and
started the power. The film says it all. No significant COAM
violation. However, as the unit rotates a bit you get a view of the
battery and makeshift splashguard and get to see the motor run fairly
fast. Not much compensation for watching, I know! 8^)
http://www.youtube.com/watch?v=6OdBa8bZHl8
http://tinyurl.com/r7e5gu
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
