Trackball Lighting

[TazMan]

Got a 3" translucent trackball (Happs) and want to make it "glow".
Would LEDs be my best bet?  If so, what mcd?
 
Thanks

[RandyT]

Got a 3" translucent trackball (Happs) and want to make it "glow".
Would LEDs be my best bet?  If so, what mcd?
 
Thanks

This is a tough question.  It depends alot on how you plan to implement this.  Generally, you will want the brightest ones possible, but you also want a wide view angle.  Sometimes these don't go hand in hand.  

I used to have a Panther XL Joystick with a glowing trackball built in.  They used a small board with 4 very bright red LEDs mounted under the ball.

You have to know a bit about electronics to know what size resistors to use based on the voltage you are feeding the circuit, the total number of milliamps the circuit consumes and the voltage requirements of the LEDs.  You have to use ohm's law.

If you could supply the specs of everything, I'll try to give you starting point.

It might be easier to use a colored 12v lightbulb, but that's gonna generate heat, and burn out regularly.


RandyT

[RacerX]

I bought a 6 volt bulb (kind of like a flashlight bulb, but a bayonet mount one) and a bayonet mount socket at Radio Shack.  There's a hole built into the Happ Trackball casing to screw one of these sockets into it.  To power the bulb, I got a 5 volt universal AC adapter at Radio Shack and I hooked it up to the bulb.  Voila!  The trackball is lit!

[slug54]

I went the LED route and I am very happy with the results.
I lit my translucent blue T-ball with 2 led's mounted at different angles. I like using the leds because they don't give off any heat and they should last a long time.
I cant remember the mcd but I'm thinking they are 1600

                          Slug54

[Ted_Striker]

To light my ball I bought a .99 flashlight at walmart.  I then unscrewed the top part (bulb reflector housing etc...) just like you would to replace the batteries.  I then mounted that thing under my trackball and wired it to the 5 volts of my pc power supply... the plastic assembly of the flashlight keeps the heat away from the trackball and the reflector give a nice wide viewing angle... works well and was cheap.

[Frostillicus]

I used a $1.45 nightlight from lowes.  Looks like a clear xmas bulb and has a protective plastic shield.  Mouted it on the wood below the trackball - it's pretty easy to wire since you just plug it in and turn it on. - Any light like this: just turn it on and plug it into your  master powerstrip(if you have one) and it will pop on when you hit the master power switch.

[RandyT]

I used a $1.45 nightlight from lowes.  Looks like a clear xmas bulb and has a protective plastic shield.  Mouted it on the wood below the trackball - it's pretty easy to wire since you just plug it in and turn it on. - Any light like this: just turn it on and plug it into your  master powerstrip(if you have one) and it will pop on when you hit the master power switch.

I would recommend not going this route.  Those bulbs can put off a lot of heat, and nightlights have been responsible for more than a few fires even when used as they are intended.

Low heat and low voltage are the way to go, and LED's last for over 10 years before burning out.  

I even replaced the light in my coin door with a white LED, but that's me

RandyT

[TazMan]

Thanks for all the input guys.

I went to Radio Shack - actually I went to three different Radio Shacks, man don't ask them any questions unless it's about a cell phone or DirecTV - but I digress  

Anyhey,  the brightest white LEDs they carry are rated at 1100 mcd with 100 degree viewing angle.  So, I snagged a few along with some reflective holders.

As far as calculating the resistors needed, guess it pays to have a father that's an electrical engineer - some of that vast knowledge must have rubbed off on me.

I'll let ya all know how it turns out.

Wish me luck, I'm going in!

[eightbit]

I've heard there are 12v LED's that can be hooked up without a resistor. Is this true? Can I run them directly off the 12v on the pc power supply without messing around with resistors?

[TazMan]

I've heard there are 12v LED's that can be hooked up without a resistor. Is this true? Can I run them directly off the 12v on the pc power supply without messing around with resistors?

The only ones I've seen at Radio Shack are real low mcd - I remember 24mcd and 100 mcd.  The 100mcd might work for illuminated push buttons, but don't think they would come close to making a trackball glow - if that's what you're going for.

[RandyT]

I've heard there are 12v LED's that can be hooked up without a resistor. Is this true? Can I run them directly off the 12v on the pc power supply without messing around with resistors?

Using the handy-dandy calculator at the bottom of this page:

http://www.aaroncake.net/electronics/math.htm

the answer is yes.  But you have to make sure that the supply is regulated (like the one in your PC) and that the voltage is within about 10% or less of the rating of the LED.  

But as always, YMMV

RandyT

[TazMan]

Hey Randy,

Want to double check my math (and knowledge of ohm's law)

Since I went with a parallel wiring scheme (as opposed to a series), my formula doubles the mA; but not the voltage.

I put it together last night and it works - nothing seems to be burning hot, etc.
I haven't actually mounted it under the trackball; but, in holding the trackball over two of the LEDs, looks like that should do the trick rather nicely.

btw - the other 6 LEDs got to 4 illuminated push buttons and the coin door lights.

Thanks for your help,
Rob

[RandyT]

Everything looks good to me!

You got the resistor value right at 210ohms and your circuit looks fine.  Each of the LED pairs is only drawing a little over 1/8th watt, so you should be plenty safe with the 1/2 watt resistors.  No harm in a little overkill on the resistors.

Good job!

RandyT