LED Light Conversion - The End Result

Bobby,

What was the driving force which convinced you to make this conversion?  Where you having difficulty with the standard lighting?

Ron

Ron

the difference is very visible. led lighting looks so much better and clearer. with led you can see the inside details of the passenger cars as people sitting. I as well just finished up my conversion on mth r142 subway set and lionel mw 18" passenger cars. They came out great. Dont mean to hijack thread from bob. I will be posting pics as well. And like bob said, a great many thanks to gunrunnerjohn for all the help. 

BOBBY O -

Thanks for your great tips, diagrams and photos for upgrading our train lighting systems. I think most guys really appreciate your info and knowledge and would like to do these projects too.

I have one request - do you have any photos of the exact wiring connections before the heat shrink was applied?

I am a complete electrical novice and not good at soldering either.

Thanks again

Great post, thanks for taking the time putting together the document. Only thing missing are the links to websites for buying the parts or maybe someone buying bulk quantities and selling unassembled kits on the forum?

I chose to assemble the kits and sell them.

It should be fairly easy to select a list of parts from Digikey or Mouser and post them.  The only problem is the peanut gallery will then start telling you that you can buy part XYZ cheaper on eBay or some other source.  The difference is, you can get good prices on a package of parts and buy them all from one source when you pick a major electrical distributor.

Thanks for posting, I saved your attachment for future use. Some electronic parts must be sacrificed during the development of all new circuits. Sometimes even when reproducing a circuit that was proven to have worked previously. Fortunately most parts are inexpensive, and always order extras. Don't ask me how I came up with this theory...

Bobby (and by reference, John) - nicely done all around.  The fact that you (both) are willing to explain these things in detail - in some cases repeatedly - is really very helpful, especially folks who are just 'tuning in' to these kinds of conversions.  Kudos for your patience.

I do have one - hopefully clarifying - question regarding your intended use.  I assume your application is for a layout with constant voltage command/control, e.g., Legacy, TMCC or DCS (or, I guess, LC/LC+), so the circuit will then deliver constant current DC to the LED strip (at a more or less constant DC voltage).  But in your nicely done MS Word writeup you say: "However, this is not for powered units with DCS, TMCC and Legacy command controls".  So I'm confused, unless you are referring to the actual locos themselves and not the lighted rolling stock(??).

If this circuit were used with conventional variable AC track voltage, presumably it will still work, but the LED brightness will vary with input voltage up to ~12 VAC??  As has been discussed in other threads, if one wanted to have a constant LED brightness in a variable VAC system, you'd have to go to a buck-boost type circuit.

Having converted LIONEL postwar and MPC/LTI 2500 style aluminum passenger cars (the ones with silhouettes), the switch from OEM incandescent bulbs to LED's has a couple of advantages.  Cosmetically, the LED strip lighting eliminates the hotspots typical of incandescent bulbs, especially for those using DCS or TMCC/Legacy.  Also, the LED's greatly reduce the current needed to light the cars.

I've toyed with the idea of revisiting a voltage doubler circuit with an LM317HVT part to cover the full range of around 5-6 volts up to 18-19 volts track power.  However, for really wide ranging voltages, the buck/boost switcher is probably the best answer.

GRJ, would that be because of heat from the LM317, or just not a good application for it?

And is the buck/boost switcher you mention the small inexpensive Asian one with the bridge rectifier already added and LM2596?

I am going to try your light boards in a couple of caboose (cabooses, cabeese?). (Still don't have any passenger cars, Lionel got my entire train budget this time around for those new command control accessories...)

Yep, the power dissipation of the LM317 when it's dropping a lot of voltage would start to be a factor.  The voltage doubler will put out around 40-45 volts at 18 volts track power, let's assume 45.  If you are running 30ma to the strips, you'd be generating a bit over a watt of heat in the LM317.  That's getting into the area where you may need a heatsink.  Certainly, at those levels, you wouldn't want to put the LM317 against a plastic shell!

It's certainly a thing that can be done, but it's something that would take a little thinking on.  It's also hard to compete with the cheap Chinese parts...

Ok, thanks for the explanation. Maybe some of this is going to stick one of these days (or finally has?).

I was just looking at your lighting kits and it said for command control and 12-19 volts. I thought you were using the constant current and the lower conventional voltages could be used as well?

I'm all command control, so they are fine for me, was just curious? Maybe I got lost somewhere in the thread you had going about them? Apparently that didn't stick.

The difference in my lighting kit is no voltage doubler, hence I'm dissipating a lot less power in the LM317T part.  If you figure I get around 25 volts on the input, and there is 10 volts (approx) on the LED at the desired brightness, I only have to handle the 15V drop across the LM317, about 0.45 watts.  That's half what the voltage doubler solution dissipates and makes a significant difference in the operating temperature of the LM317.

Ron045,

What drove me to the LED conversion?

I currently have 12 8-car passenger trains and two 6-car El trains running, 6 of which consume power on my layout at one time. Also I have several lighted cabooses on my layout. That's a lot of current flow from my single Z4000 power supply, and I need more than 50 LED conversion circuits.

So the bottom line reasons for my do-it-yourself LED conversions are to reduce the current draw from my Z4000, and to make the cost of the conversions affordable.

Next I will be converting the 14 switch controllers and switch lanterns that draw track power too.

Bob, per chance did you measure the current on an incandescent car and the LED conversion?  I recall gunrunnerjohn had posted this information, albeit not for your specific circuit or car, but it was dramatic.

The LED upgrades typically use around 20-40 ma, depending on how bright you like your lighting.  The MTH 18" passenger cars with incandescent lighting clock in at about 1/3 amp.

For my measured usage for converted and unconverted car...

LED Lighting: .025A

Incandescent: .33A

Looks like around 8% of the current draw of the original car.  All measurements at 18 volts.

Thanks GRJ and Bobby O. I've learned a lot about LEDs.  Great work.

grj, thanks for posting the information--only using 8% of the current draw compared to the incandescent car is very significant.

I see why Bobby Ogage has undertaken his extensive conversion project.

I have converted 15 Rail King passenger cars to LED lighting. The sketch below is the general arrangements I have standardized for my trains. Before you start stringing wires, it's a good idea to do the following detailing beforehand:

> Interior painting;

> Decorate the dining tables;

> Adding passenger figures;

> Attach a drumhead to the observation cars;

> Add baggage and or freight in the baggage car and combine.