Many moons ago Elektor came out with an issue which contained nothing but
projects using empty soft drink cans. Among the assorted circuits in there
was one where the can had a column of LEDs mounted and was rotated using a
motor. An LM3914(or one of those chips which drive an LED bargraph based
on a voltage input) chip was connected to these LEDs and the result was
an oscilloscope! The time sweep is adjusted by changing the speed of the
motor.

Memories of the issue are pretty dim now... One of the projects was a can
with a battery driving a motor with an off-centre weight on it. A mic
circuit in the can then responded to hand claps and would roll the can when
that happened.

Regards

Prashant
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  Prashant Bhandary             | Tel:  +61-2-9662 5299
  Spatial Information Solutions | Fax:  +61-2-9662 5348
  Roads and Traffic Authority   | Email: prashb@rta.nsw.gov.au
  Rosebery NSW 2018, AUSTRALIA  | "2b|!2b" - William Shakespeare
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