LUGNET News : ~330/FAQ/Build/lights


Cary Clark / FAQ / Build / lights

How can I fabricate lights?

From Martin Legault: !

An LED will do, use the 1 3/4 mm size since they fit great into technic holes.

Brightness will depend on the current you send through the LED. In general, 10 mA will work just fine. The formula for current is C = T / R, where T is the voltage and R the resistance. The LED will drop about 2V (between 1.8 - 2.2, depending on the colors).

For example:

     R     led
---/\/\/---|>---
     7V    2V

...so take 7V, divide it by .01A, and the result is a 700 ohm resistor.

700 ohm resistors are NOT the standard value, so you could take a 680 or a 720 ohm resistor.

From Tom McDonald: !

If you’re not math-oriented like me, I’ve found that if you use 5 ordinary LEDs connected in series with each other using 9VDC they work fine. If you use LEDs that soak up more current than your average LED (often because they’re bigger and brighter) you can use fewer LEDs. I tried to use all lego for custom lighting on my train station platform; but alas, I had to use 8 gauge copper wire for pole strength and conductivity along with insulated 30 ga. I used pneumatic tubing for the outside of the pole, and clear 1x1’s fit right over my LEDs :)

I’ve also used light bulbs. MagLite flashlight bulbs work great as they’re very bright for their size.

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