Instructables

Rainbow Stick and a Crystal Ball

Picture of Rainbow Stick and a Crystal Ball
DSC_4375.JPG
Okay... There are plenty of Instructables here that explain how to build LED circuits, so we will not be reviewing that except to provide a few links.

My 'ible on Light Pens covers it as well as this tutorial on my web site.

Also see LEDs-for-Beginners. And search for LED to find many others.

Here are 2 recent creations.

The first is a light stick I built for the Maker Faire. It is a great light drawing device that will make a big picture quickly. See our Best of Maker Faire Light Doodles here.

The second uses a geode we found in a rock shop which makes an unusual home display.

 
Remove these adsRemove these ads by Signing Up

Step 1: Rainbow Stick

Picture of Rainbow Stick
DSC_4415.JPG
DSC_4418.JPG
DSC_4417.JPG
DSC_4427.JPG
mf2.jpg
This device is an extension of our light drawing pens. I strapped 6 different colored LEDs to a 2 foot long stick with 3 AAA batteries and a switch postioned to easily turn off and on with your thumb.

The 3 AAA batteries are wired in series for a total of 4.5 volts.

The LEDs are wired in parallel to the power source and the switch is inline so they all light at once.

Since each LED has a different forward voltage and maximum current load, I wired a different size current limiting resistor to each. Here are the specs.

Power source is 4.5 volts

LED...................| Forward Voltage | Forward Current | Resistance

Super Blue.......| 4.0 volts................| 25ma..................| 20 ohms
Deep Red.........| 2.5 volts................| 25ma..................| 80 ohms
Yellow Green...| 2.5 volts................| 25ma..................| 80 ohms
Super Orange..| 2.5 volts................| 25ma..................| 80 ohms
Light Green......| 4.0 volts................| 30ma..................| 18 ohms
Awesome.

Your Instructables are always awesome, keep up the great work! I want to build one, and I have LED's -- a lot of them now. Thanks for the Instructable!

+5/5 stars.
(added to favorites)
find a cheap place for leds?
i know right
I love the crystal ball but how do you find the ball
unklstuart (author)  funnylily231 year ago
Thanks. That is a geode they I bought at a rock shop.
thanks
kcls4 years ago
I love the rainbow stick... nice job!
bybabylove5 years ago
this is a very good idea 4 my science project and its goo it got me a A+ on my report card
Wonderful Work! Congratulations!
tudgeanator5 years ago
Awesome. I have an idea! You could put loads of LED's really close to each other on the end of a big paintbrush and use that to 'fill' the pictures in!
sponges5 years ago
Awesome. The crystal ball looks like a prop from Star Trek TOS XD
"It's a being of pure energy!"
Plasmana5 years ago
Wow! I love your rainbow stick, great work! I want to build one, but unfortunately I used all of my LED's to make this project, I will have to buy more LED...
http://www.instructables.com/id/Spinning-rainbow-light-wheel/

4 star rating.
Pro

Get More Out of Instructables

Already have an Account?

close

PDF Downloads
As a Pro member, you will gain access to download any Instructable in the PDF format. You also have the ability to customize your PDF download.

Upgrade to Pro today!