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Yard Master & Research
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Discussion Starter #1 (Edited)
Lately, I have been ignoring my LED curiosity. Today I was in Radio Shack, shopping with the family. I mowsied over to the electronic parts and hit paydirt. Tis the Season! :eek::DI found surface mounted LED's. I bought 2 white for 2.39.each. Here is one operating on 3 volts.

The orientation has the positive feed to the bottom and negative at the top. Comparable to the bulb LED of the the long lead being positive and the short negative.




Now for the technical. They are low profile not actually a surface mount but ideal for our use. The surface mount I have seen at FRY's on the west coast were prewired to a strip and about half the size of the one shown. They have a 130 degree angle of viewing.They are advertised as high inensity but the picture was distorted by glare. High but not super bright.The last photo I could see the clear case. Operating range is 3.5 to 4 volts DC. These are ready to solder to a common board. They have 4 leads to make it easier to string out. Two leads for power and ground and two for the next one. Two could easily light an O scale car. Ideal to light a scale workshed.So far in my work AC or DC power suppllies have worked. The problem has been on board ligting from the track. A 9 volt battery will work. But the reversing polarity of the rails is tricky and DCC is entirely different. The only sure way to light is with a voltage regulator and bridge rectifier on board. For the moment just sit back and say Cool!:cool:

Product number is 276 0024
 

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Yard Master & Research
Joined
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10,752 Posts
Discussion Starter #2 (Edited)
Research

I have been reviewing the LED uses. One new problem is the wattage used when using AC power. Common resistors are only rated at 1/2 or 1/4 watts. It appears for use that one watt resistors are more practical. My flashers are ok it is mainly the use of the LED with transformers. I am working on a spreasdsheet too. I am trying to incorporate an article from CTT in SEPT 08.
Radio Shack doesn't have one watt resistors. More on this later.

More: Radio Shack has 1 watt resistors in stock. 10,100,1k. So I can get them locally.Using my two new LEDs in anti parrellel with 16 volts ac I calculated 280 ohm resistance. So 3 100 ohm resistors will work and give me .59 watts of power used. Now all I need to do is buy and assemble. Maybe I wil try this in my old station house. It may be small but the only building I have that is larger and is 3 dimensional is my wife's dollhouse.It would be nice to have an engine shed.
 

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Yard Master & Research
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10,752 Posts
Discussion Starter #3 (Edited)
Finished project

It works but with the large dispersion it does not have the brightness of the bulbs.
See for yourself, the only room available was a doll house.
I cut the board to separate the lights.


 
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