So, I was looking around on Hackaday and found this
post about a starlight
project from Zach. That inspired me to make one of
my own (my 3 month old baby loves the results.) As with
any project, there are a few ways to get anything done,
none of them necessarily wrong. I chose to use a gear
reduction motor instead of a servo and micro controller. I
also found some automatic RBG leds that change color every
few seconds, by themselves. The details are below.
Please forgive my crude schematic. I think it gets the
12 volts comes into the motor from the power supply
to turn the light ball.
12 volts also goes to the 7805T to regulate the
voltage down to 5VDC for the LEDs
I used a 100 Ohm resistor I found for current
control, should draw ~0.050 amps (~50mA), nice and
The circles you see in the picture are the foil tape
slip rings, the LED leads drag along these rings as
the light ball rotates.
I also tied the anodes and cathodes of the LEDS
together, so if one lead looses contact with the slip
ring, the other could still conduct.
First, I poked holes in the pingpong ball, small
ones to let light out and two large ones to hold the
After I soldered and epoxied the LEDs in place I
painted it black.
The copper foil tape, was simply placed on the
motor, around the rotating axis.
Then a small strip cut away to make two conductors
for the slip ring. Note the wires already soldered
to the strips. and extra piece of foil was placed
over the blue wire for continued contact:
I soldered all the components together:
and put the in a fuse box, with some double sided
In the above, you can also see I have bent the LED
leads to contact the foil slipring as the ball
To attach the light ball I found a sharp screw,
with a head that fit snugly into the center of the
motors shaft. Then, I applied power to the
motor to rotate the shaft counter clockwise. This
caused the screw to turn as I held the light ball,
pulling the assembly down on the screw threads and
ensuring the leads had a good connection to the slip
Below is a short clip of the unfinished finished
device (just to show the effect of the LEDs):
If you made it this far, Thank you for viewing. I
know, I'm no good at building webpages, or even
designing them, I just wanted to get my version of
this project out there. I do welcome any comments or
questions you might have.