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Discussion Starter · #1 ·
Hi , i would like to replace some burn't out, as well as install some new L.E.D. lighting inside some of my 1/32 scale slot cars that currently don't have front head lights from the factory. The problem is on the Web Sites they commonly tell you that a given light has a certain degree of light variance I.E. 25 Degrees. If you have read into this that i don't now what i'm talking about ,then you are right. So does anybody now what degree or width ( spread ) of the light beam should be for a slot car. Feel free to jump in here before i buy something i don't need. Thanks Robert V.
 

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Digital "Tea Boy"
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Hi Robert,

I use these. - scroll down a bit and you'll see which model I'm referring to. The website in that link has a "technical specification" pdf file that you will be able to see the angle of the beam.

HTH.

 

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Discussion Starter · #4 ·
HI Keeto, thanks for the info. The info claims the angle is 30 degrees,for some reason i was thinking 20 to 25. But at least i can start looking for some L.E.D. of that dimension and that light angle. I am going to try to find something in the Automotive end of L.E.D. lighting because it's allready 12 volts and dosn't need any transisters to step it up or down. Thanks Robert V.
 

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Mr. Olufsen
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Keeto,

What a brilliant guide, thanks! I guess the brake light LEDs you would normally use are the 1.8mm Red LED High Power 1120mcd Rapid Online Item HERE, am I correct?

Br,
Christian
 

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Digital "Tea Boy"
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Yes, those are the ones Christian. I'll update the links. Thanks for that.
 

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Or, you could go this way.
Info needed. Forward voltage of LED, Current, (20 - 30 Ma) Source voltage, number of LEDs's
See this link for more help. Do the same as the link above, without the PCB.

LED

One I did a while ago. 8 LEDs, 4 front, 4 rear. 4 Bright white + 100Ohms res. 2 Bright Red 470Ohm, and 3 Bright Orange 330Ohms. (Running at 16V track, Hornby WW)





Lets KIS
 

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Rich Dumas
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LEDs operate at low voltages, usually 3.5 volts for white LEDs and 2 volts for red LEDs. If the voltage is a volt too high the LED will burn out at once. For automotive use the LEDs would have a dropping resistor built into the housing. Make sure you know what your track voltage really is before you use LEDs. Light kits like the ones that Ninco and Slot.it sells include voltage regulators. When people add lights to their cars they usually just use dropping resistors and there are many online calculators available to help you choose the correct ones.
Here is one: http://led.linear1.org/led.wiz
 

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Saviour, there is something strange about that LED formula link. - The link Rich gives is the same link.
I like the way it can display schemetic or wiring diagram, and for large arrays, it shows some alternate formulas, and my electronics knowledge is pretty limited, so maybe Rich or someone else who understands more can help.

But the formula it uses, seems to calculate mildly different values to the link I copied and formularized, then, when you get to a value of say 10 LEDs, it says a 1 ohm resistor is needed for a 12V input, 24ma output and 1.2volt LEDs, whereas I think it should be a 43 or 47 ohm (standard value) resistor.
Other figures are "nearish enough" in the world of LEDs.
The movement in value of resistor from say 9 to 10 LEDs indicates it may just be a bug in the formula.

Here's my formula link - an excel sheet online LED Powering Formula
LED Powering Formula
 
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