Lighting the trackball

The trackball Im using for The Rage has a translucent ball, which means the ball can be lit.
The light source mounts to the bottom of the trackball. A hole in the bottom lets light through, to make the ball glow.
This is a really cool effect, and if you can afford the extra cost, get one for your arcade. (Its really not that much more expensive, and well worth it, in my opinion.)

The trackball came with a 12 volt incandescent bulb and socket, but I used that on the marquee, so I had to come up with a different light source.
I used a jumbo red LED. I used red because thats the only color Radio Shack had at the time.
The ball is orange, so the color of the ball with the LED illuminating it is a reddish orange. It doesnt look bad at all.
The LED is a Jumbo Super bright, Radio Shack number 276-086.
It is rated for 40 ma max current, so to use it with my 12 volt supply, I selected a 330 ohm 1/2 watt resistor, to limit the current flow through the LED.
Using Ohm's Law, I=E/R, or Current (I) = Voltage (E) divided by (/) Resistance (R)
The LED drops about 2.4 volts, so I subtracted that from my supply. (12 volts -2.4 volts =9.6 volts).
So, 9.6/330 = .029 amp, or 29 ma. (result rounded.)
This is well below the maximum current of the LED, so I should be ok.
The LED is very bright. It is uncomfortable to look directly at the end of it.
I mounted the LED and the resistor to a small piece of perfboard (also available at Radio Shack).
I then attached a piece of speaker cable to the LED and the resistor. The speaker cable will be the wires that will tie into the 12 volt supply.
Here is a picture of the finished board:

The board will mount to the bottom of the trackball. The LED will shine into the trackball through the hole in the bottom of the trackball.
The LED looks clear, but it glows red.
The hole at the end of the perfboard will be used to mount the perfboard to the trackball.

Here is a picture of the LED powered up.



And here is the end result, pretty neat huh? (It looks a lot better than this picture.)


I didnt get a good picture of the the perfboard mounted to the trackball, so I drew a rough sketch, which should give you an idea how it's done.

At the bottom of this sketch is the electrical schematic of how the resistor and LED hook up.
I wired the LED, the resistor, and the speaker wires by twisting their leads together and soldering. This method is called point-to-point wiring.

The circuit must be hooked to the power supply as shown. It wont hurt anything if I hook it reversed polarity (backwards), it just wont work.
So when I hook it to my power supply, if it doesnt come on, I will just reverse the wires.
(One of the speaker wires is marked with a red tracer, I'm using that one for the positive, just so I get it right the first time.)

If you have any questions, just email me. I'm no expert, but if I can help I'll be glad to.
email: kenrager@hotmail.com

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