# LED Lampost



## T-Man

Just to expand on some thoughts. I originally introduced the idea in the how to thread on O scale. Most of the electric projects I do, can be dno e in other scales. The Lampost is one of them. You just consider the size and power supply.

Today I am using a 5mm LED . 3 mm can be used for smaller scales.

I use a coat hanger for support and a piece of telephone wire insulation to hide the wire.



















To be different I used a part to a Three LED flashlight.










I cut up the three sections. Soldered the wire to the LED and epoxied waht was exposed.



















And a bench test with a three volt battery.


----------



## xrunner

Nice. Good use of available materials. :thumbsup:


----------



## T-Man

Next is power connection. The easiest for both AC and DC use is a Bridge rectifier that I make with four 1N4001 Diodes. You can use smaller diodesBut you ca also use it to power more than one post. I am planning on three.

 Examples are seen in the 2020 LED thread refresher.










The last part is a resistor. Since the post are spread out each one will have one. A quarter watt will work. Anything from 650 ohms to 1000 will work. All accessory power packs operate on 16 volts ac.

You can operate on DC power from the track too with the same setup.


----------



## T-Man

Metal coat hangers are getting harder to find.


----------



## T-Man

*DC operation*

Trying to keep it simple, telephone wire is available, on the other hand the old serial port printer cables are waiting in boxes at thrift stores. I can't remember who just suggested that idea. hwell:

Another item is a DC output wallwart used to charge phones etc. A 9 or 12 volt can be used. The hardest part is cutting off the plug and determine the wire polarity. A little figure on the adapter will tell you or use a meter. This plan uses three LEDs with a 470 ohm resistor. It wll work with 12 or 9 volts. You can try a 330 with the 9 volt for extra brightness. If you use the LED to determine polarity makes sure the three are wired together with a reisistor. 

Another option is to visit a Michaels and buy string lights from LEMAX. Halloween line should be out now. They run on batteries but they sell ready to plug in adapters too. Their buildings add an interesting dimension to the O scale lot too.


----------



## T-Man

*LED Source*

The easiest way is to go to a dollar store and see the LED items, for example a flash light. Some are blue but white is getting to be more common. Then you have alocal Radio Shack store too. ALso there is a huge 8 or 10 mm LED there.

My flashlight was run by three triple A batteries at 4.5 volts DC. I checked the wiriing and they were in parrallel. My three volt check battery ran the set up.
Come to think of it it was a push light not a flashlight. A sticky light for the closet. They may be sold in a three pack for $5 at a Home Imrovement store.
Also LED Xmas LED replacement bulbs will coming out shortly at these centers.


----------



## Big Ed

T man any plant that has uniforms most of them are brought back clean on the metal hangers.
We have a bunch in the locker room, I have a bunch in my garage.
If you know anyone who works in a uniform ask him for a bunch of hangers.

Nice street light, some scrap copper tubing/pipe would work nice too.

My plastic hangers are solid.


----------



## T-Man

That is good to know. Also brass tubing is found at hobby stores.

To work with the LED you have to know polarity. The plus or minus side. In layman terms the current goes IN the plus and OUT the negative. It works for me. I use a 3 volt watch battery to test as I go along the project. For phone wires, I use in color pairs, solid and color/white. The solid attached to the positive lead. Once assembled all you have is the wire. The battery test wil work until you add the resistor. Then you will need a larger battery. For 12 volt systems a 9 volt battery will work. I aslo have a handy 12 volt wallwort with painted leads to help.


----------



## gunrunnerjohn

T-Man said:


> The easiest way is to go to a dollar store and see the LED items, for example a flash light.


The Dollar store is where I got my flickering LED candles, three for a dollar. Best deal I've ever seen!


----------



## T-Man

That is a bargain! :thumbsup:

I made board to Tie the posts together to a power supply. I used a makeshift bridge to reduce line voltage and each LED has 650 ohms. A convienent use, Anything from 470 to 1000 will work. The higher the number the longer the life.

I did mark the pos terminal connections for the solid blue wires. Load terminals are to the left the power supply terminal to the right.










Plenty of room to add more.


----------



## Nuttin But Flyer

T-Man -- You get your name from that comic book or the other way around?


----------



## T-Man

The wife suggested the name. I needed one to join this forum. Later a thread appeared on How You Got Your User Name. Reckers had a lot to do with it. He used Google images and found signs with his "Recker" name. Only then did I get the idea to Google it and the comic came up. 

I can't find it now that you asked. hwell:I just use it as an avatar.

Some else joined this forum and claimed that was his nick name. I forget who but it's all in here someplace.


----------



## T-Man

*Tower base*

First I used some 5/8th dowels and slightly beveled the top. Then I drilled an 1/8th hole for the hanger and a smaller one for the wire. ELmers was used to attach it to the base a 2 by 3 quarter inch ply. I run the edge with scatch putty to smooth it out.


----------



## T-Man

A sketch of the board. This leaves the LEDS free of soldered resistors. I can change them at will.











The bases were 2 by 4 inches but I cut them down to 2 by 3.


----------



## T-Man

*The end*

With assist back lighting




















and without.













See also the Type G Signal Tower


----------



## T-Man

This is the type of light I used to build the lamp post. Mine were bought in a yardsale for 50 cents apiece.


----------



## Mrs.NIMT

Those are great! I am going to have to remember this thread...


----------



## T-Man

Thank you Mrs. and welcome to MTF.

Links to all my projects are found in my signature link.


----------



## Fighterpilot

As I understand this LED lighting thing, you must match power to the LED. Therefore three 3 volt LED's can be wired in series to one 9 volt battery or 4, 3 volt LEDs can be wired in series to a 12 volt battery. Am I correct here? I thought about doing some lighting in this manner using 12 volt DC wall chargers as a power source. I could use 2 circuits each wired in series with 4 lights each and hook them in parallel to the 12 volts source. Do 3 volt LEDs come in different output levels (watts or milliwats)? To determine the load in amps or milliamps wouldn't I just divide watts by voltage to get the amp load?

Could you hook up 6 LEDs in series and connect them to 18 volts AC. I have some small light fixtures designed to be side lights for trailers with regular light bulbs, not LEDs. They are meant for 12 volts DC, however, I tested them on 12 to 18 volts AC and they seem to work just fine. Using them to light up a couple of buiildings on my layout. Are the LEDs compatible with AC voltage?


----------



## gunrunnerjohn

Don't connect LED's directly to AC, they'll enjoy a very short life. They may last for months, but they won't last like they should. A series diode will protect them from the AC.

Basically, LED's are current devices, and not really voltage devices. The best way to use them is to control the current to them. They are also DC devices, and if they experience a reverse voltage greater than 5-7 volts (depending on the specific LED), that will damage them.

I recommend always allowing overhead and using series resistance to limit the maximum current to the LED.


----------



## ktcards

T-Man said:


> Next is power connection. The easiest for both AC and DC use is a Bridge rectifier that I make with four 1N4001 Diodes. You can use smaller diodesBut you ca also use it to power more than one post. I am planning on three.


You can get a full wave bridge rectifier already wired (saves all of that wiring and soldering) for as little as $0.50 each. Add a capacitor and it becomes a constant lighting unit which will work on either A.C. or D.C..

I put several together and the total was less than $1.00 each.

Ray


----------



## T-Man

Don't stop there. How about some details?

I bought diodes in bulk, plus I can arrange them on a board as needed. I would like to see the board you use. Is yours for any specific scale?


----------



## ktcards

T-Man said:


> Don't stop there. How about some details?
> 
> I bought diodes in bulk, plus I can arrange them on a board as needed. I would like to see the board you use. Is yours for any specific scale?


This concept has been discussed before. Here is a link to the thread.

http://www.modeltrainforum.com/showthread.php?t=15513

Ray


----------



## T-Man

A 1.4 amp diode and 680 uf capacitor. Got it! :thumbsup:

I just like to see what people are using.

I tagged the thread as LED constant.


----------



## gunrunnerjohn

I use the CL-2 constant current source for truly constant intensity LED lighting. If I want more current for multiple LED's, I use an LM317T in a constant current configuration.


----------

