nipkov disc

This was invented by Paul Nipkov

print,cut out, fold up fan blades. Below is a code disc

print, cut out, glue to back of nipkov disc, program by cutting out slots, glue cardboard disc to center (dotted line), make bearing out of thumb tack and plastic bead, make arm out of bent wire attached to bearing which shines toshiba high-brightness led through the slots as it rotates (towards your face as you blow), hold small plastic mirror to reflect intermittant beam of light onto disc. You get as many images as there are dots, each one scrolling radially by one dot row.
You have to make the disk very flat, any vibration will blur the image which is pretty faint anyway. Make the bearing as near the disk as possible to minimise wobble. Use a drinking straw to blow the windmill.

movie wheel
Benham disk
instructables zoetrope
simple technique for laser scanning
simple laser pattern
link to site about Paul Nipkow
Philo Farnsworth on 'I've got a secret'
Measuring the speed of light

my email is
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