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LEDs for Signals and Lighting

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  • Member since
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  • From: North Dakota
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LEDs for Signals and Lighting
Posted by BroadwayLion on Sunday, December 14, 2014 12:33 PM

Merry Christmas! Now is the time for all good LIONS to go to Walmart and buy LED sets for the train layout. LED technology is growing by leaps and bounds (trying to stay one step ahead of the hungry LION, I suppose). LION was still building signal masts with 30 year old LEDs. Now him try something new.

These sets have a small LED inside of them. The LED is the color of the lens, but not white. White LEDs still cost more money, and so it behooves manufacturers to use the colored LEDs. The new LEDs are almost water clear in the off state, but are very bright and vivid when lit.

The cathode has the shorter lead and the larger flag inside of the plastic. This is the negative pole of the device. The anode then is the longer lead, and the smaller unit inside of the device. It is the positive pole of the device.

This is all well and good, but when you recover LEDs from the lighting sets you may break short some of the leads, so rever back to the actual anode and cathode inside of the LED when you wire them.

When you recover them from the lighting string you can observe several things about them.

First, the plastic housing is keyed, it cannot be installed into the string backwards. Indeed from this picture, you can see one side has longer plastic that the other, and that helps the assembly worker in China insert the LED correctly. If you buy sets from different manufactures you will find that they manage resistance in different ways. Some will have a large plastic housing in series with the set, othere will have little bittity resistors attached directly to the LEDs. These you can ignore while salvaging LEDs, you will just clip them off. But do not try to reverse engineer these sets for 110volt service. That could be very dangerous.

You will find that the plactic parts are very tightly assembled. The manufacturer does not want you to open them up as this could be dangerous to primates. I found that I needed a tool to hold the plastic base, and another to grasp the transluscent do-dad that covers the lamp. But they do indeed come off.

As I have said, these are much much brighter and more vivid than the 30 year old device that I had heretofore been using. An older signal can be seen out of focus in the distance. Perhps these are almost too bright. I doubled the resitance to 2K ohm, and they are still too bright. I shall play with the resistors and then find out what size I will need to buy. Still, I do like the signal reflecting off of the rails, as this is very prototypical, at least on the NYCT.

LION has very neatly placed the LEDs of him in these bottles so that they do not spill all over the shop, and that him can find the ones that him wants to use on the signals of him.

As far as lighting goes, some are "Cool White", and others are "Warm White". The Cool white emiulate flourscent and mercury lighting, the Warm White emulate incandescent. You can get them with rounded tops that focus light like a spot light, or flat tops that have an inverted cone top and spread light out around it like a flood light. You can get T1 (3mm) or T1.5 (5mm). In lighting the letter refers to the shape of the lamp (T=Tube), and a number which is the diameter of the lamp in 1/8ths of an inch. LION is going to phase out the larger 5mm LEDs, as the 3mms are more realistic for most applications.

In addition to the LEDs themselves, also take time to salvage the wire. For most of the length of the set you will see three wires, and only one has sockets on it in series. Thus on a 35' length of holiday lights, I can recover 70' of wire for the layout.

 

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by peahrens on Sunday, December 14, 2014 4:51 PM

A timely overview, LION.  Another source is Lowes, where I found inverted cone warm white 5mm LEDs in strings of 100 a couple of months ago.  They had no cover over the LEDs so the LEDs slid out when their wires were straightened.

 

Paul

Modeling HO with a transition era UP bent

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Posted by tomikawaTT on Sunday, December 14, 2014 9:41 PM

The really sly, cunning trick is to go shopping for those Christmas strings a day or two AFTER Christmas.  The stores are anxious to get rid of unsold holiday inventory and the discounts prove it.

Pre-LED, I scored a bunch of 2.5v lamps pretending to be icicle lights for about two cents a lamp, sockets included, wire extra.  It's actually less expensive to use four in series across the 6.3VAC lighting circuit than to buy and install the proper resistors - and no problem, since I have thousands of them.

Chuck (Modeling Central Japan in September, 1964)

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Posted by rrinker on Sunday, December 14, 2014 10:13 PM

 I am going to see if this works this year, since most stores are selling almost nothing but LEDs. In past years, a day or two after the holidays, the shelves were bare, except some odd colors no one wanted. However, when strings of 100 are now like 10 bucks regular price, it's still a steal.

              --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by hon30critter on Monday, December 15, 2014 1:41 AM

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by wickman on Monday, December 15, 2014 2:38 AM

This is an excellent topic I always find interesting.

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Posted by xdford on Monday, December 15, 2014 2:56 AM

Hi there,  I have my own for a while using bidirectional LED's and the net cost is about $1 each... details are on my site

http://www.xdford.digitalzones.com/construction%20of%20a%20model%20railway%20signal.htm

also for some ground signals, admittedly ersatz in nature...

http://www.xdford.digitalzones.com/modelrr11.htm  which are now functioning with Bi directional LED's and have done so for a few years now! 

 

Hope this is of use,

Regards from Australia

Trevor

 

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Posted by BroadwayLion on Monday, December 15, 2014 6:46 AM

tomikawaTT
The really sly, cunning trick is to go shopping for those Christmas strings a day or two AFTER Christmas. The stores are anxious to get rid of unsold holiday inventory and the discounts prove it.

 

Yes, LION do this, but only if there are leftovers that him wants. You want to be choosey, then ewe buy before Christmas and pay more.

 

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by peahrens on Monday, December 15, 2014 8:53 AM

hon30critter
You can get cheaper LEDs through eBay

Excellent point.  I can recommend this also basis experience with small resistors.  In the LED case I wanted immediate supply and Lowes had them.  But with resistors I got some U.S. stock quickly through Ebay for immediate use, at a bit higher price plus shipping.  Then I ordered more variety from China, lowest price and free shipping, if you're willing to wait 2-3 weeks.  All arrived reliably.  Do read the descriptions carefully as some may be sketchy enough that you're not sure what (watt?) you're getting.  And if you're lighting structures, check out the 16' LED strip lighting also, where they can be cut into 3-LED segments that are set up for 12v DC.  Also on Ebay.  

Paul

Modeling HO with a transition era UP bent

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Posted by chutton01 on Friday, December 26, 2014 8:14 PM

I just got back from our friendly local Wal*Mart on this day after Christmas. Some observations were that they were selling (clearance) a whole lot of Incandescent mini-light strings, not LEDs but filament bulbs! I had no interest in them, and I'm not sure why people would buy them - they didn't seem cheaper than the equivalent LEDs, and they run hotter and burn out.
Second, the "cool white" LED strings (strings, to distinguish between decorative  holiday lights most lootable for their LEDs, vs ornaments, stars, lighted trees and less fertile sources) were available only in 5mm by one manufacturer (in strings of 100); the "warm whites" came from a different manufacturer in strings of 50 3mm LEDS. Cool White have no hard-to-pull-off covering, while the warm whites do (requiring at least 3 grunts and 5 cusses to remove).
Looks like everything is inverted cone, and the cool whites worked out to be 3.5 cents apiece (excluding labor, of course), while the warm whites were more expensive at 4.8 cents apiece (and more labor, dangit). I'm sure these prices could be beat on eBay, but it seemed cheap enough.
Brother Elias's idea regarding bottles of different LEDs seems like a good idea, and I plan to implement it, so ...maybe you can send in another tip to MR's Workshop, Brother Elias.

I was searching around a bit about shaping LEDs, and came across this site, which seems a bit behind the times - almost a dollar for 3mm white inverted cone LEDS, while we quibble over a penny difference apiece store vs eBay? OK, they include a 470Ω resistor, but still I must be missing something here...

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Posted by hon30critter on Friday, December 26, 2014 10:19 PM

chutton01:

I have a feeling that the website you referenced is indeed a little behind the times. The latest date I could find on the site was 2011, and at that time $1.00 a piece would not have been a bad price for white LEDs. I noted also that there was no reference to 'warm white' LEDs, and none of the lights in their examples were warm in tone.

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by gmpullman on Friday, December 26, 2014 11:37 PM

If anyone wants a nifty little dwarf signal you can get these guys already in a holder for 25¢ each.

http://www.allelectronics.com/make-a-store/item/led-183/red/yellow-bi-level-led/1.html

You can gently bend the leads straight, swap the red for the yellow and if you flip one over you have +- and -+ so when you bend the leads back down * they will be properly oriented to solder together, with your wire. Put it in-line with either leg of your Tortoise and you have a signal protecting your siding. I glue a short piece of coffee stirer with the front cut on the bias for a visor, glue it to a little square of styrene (I've used LEGOs) for a base. Cheap and effective!

For facing point you can get yellow/green too.

* not all of the LED housings allow you to remove the LED. The ones I got at All Electronics you can. The ones at LEDswitch, you can not.

For making signal heads I find that the 1.6mm axial water clear LEDs are the best. When you bend the leads back they fit inside the Oregon plastic signal head just right. Like Dave, I find the best deals on ebay. I have been dealing here for years and always get good service. http://www.led-switch.com/

Happy New Year! Ed

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Posted by BroadwayLion on Saturday, December 27, 2014 4:12 PM

Been there, done that, got the pix to show for it.

WEnt back to using wooden masts. I just like them better.

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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