New LED passenger car lighting kits

quote:

Originally posted by Scrapiron Scher:

I don't know a 470 uF 50V electrolytic capacitor from a flux capacitor

The Flux Capacitor has three leads.

quote:

The lighting current prior to modification was 2.9 amps at 17 volts for 4 illuminated cars with 4 bulbs each. After the modification, the draw is .08 amps. That's a 36:1 improvement!

Wow, that says it all right there. Not only that, but you'll reduce the possibility of warped shells or cracking paint since there's (almost) no heat associated with the LEDs. That, and you'll most likely never have to replace a bulb in them again.

Great step-by-step Dale, thank you.

John

Yo guys... just wanted to let you know real quick that I wired up my LEDs last night with the advice from this thread (thanks John and Dale!) and they worked perfectly Now just going to figure out how to mount and permanently wire into my MTH passenger cars.

Thanks again! I'll post photos soon.


Chris

I've gotten so much from these forums, it's nice to give a tiny bit back.

LED lights can provide solid color to vehicle, or flashing, chasing color. They are available in ground lighting kits, LED screw lighting, accent lighting, beamers and more, adding versatility and choice to cars accent lighting.

4x4 shop

What value is used for the polyfuse, and how do you add a voltage doubler? Thanks.

Here's a voltage doubler that drives LED's from varying track voltage. This works down to 6-7 volts and still maintains full intensity. Note that if you run at 18-20 volts on the track, you might want to clip on a heatsink to the CL2 as you'd be nearing it's power dissipation. Here's one persons solution. DIY Heatsink for Small Transistors

Here's a commercial heatsink for TO-92 packages. HEATSINK TO-92 .72" BLK - 575200B00000G

Anyone have pictures to share of passenger cars that have been converted?

quote:

Originally posted by Popsrr:
Anyone have pictures to share of passenger cars that have been converted?

Did you look through the whole thread? Here's just one that I posted, there are others.

Various circuits shown here (see LED circuits) to suit your needs as well as mounting techniques and LEDs used.

http://www.jcstudiosinc.com/Bl...tegoryMain?catId=426

Dale H

John,

 

Thanks so much for this diagram.  Would you be kind enough to put together a list of the above components and source.  I just ordered the roll of led's mentioned on the previous page and have several K-Line Madison coaches to do.  I will probably only use 1 CL2 as not to have too much light.

 

Thanks in advance,

 

John

Well I have now made about 20 of the LED Strips with the help of all of the great tips on this fourm. It really goes pretty fast once you do a couple. Special thanks to Dale and Dave for all of the step by step! I have only installed one strip so far because as others have noted, half the battle is taking the car apart!

 

I am also still seeing a fair aount of flicker.

 

Can anyone give me a recomendation on a good capacitor to use to stop the flicker? I used the 470 uF 50V from a post above and really did not see a difference between the lights with or without the capacitor. I have pleanty of room for something larger, just not sure what I should buy.

 

Any recomendations are apreciated

 

THANKS AGAIN FOR A GREAT THREAD!!!

John, I buy most of my stuff from either Mouser www.mouser.com or Digikey www.digikey.com.  I'd post a formatted link, but with the new forum, I can't seem to find the method of posting a link.

 

As far as capacitors to stop the flicker, the bigger the better.  I'm guessing you could use a higher value with a lower voltage rating across the LED strips, 25V should be plenty since they'll be running at less than half of that value.  Try a 10,000uf capacitor, it should reduce the flicker for anything but a really huge power hit.  I'm assuming 20MA through one CL2.  You can also use the higher voltage rating capacitor across the output and use a smaller value, say 4700uf.

Are you running Command mode?  If so, the 470 uF should be plenty of hold time.  The capacitor is across the bridge output, and it is sitting at nearly 25V.  That gives plenty of discharge margin before getting down to about 13V - the minimum actual input voltage to the CL2.  I calculate about a quarter of a second.

Do you have both sets of trucks feeding the bridge?

One idea that has been floated previously (and is a good one), is to put a resettable fuse between the two pickups so that a derailment doesn't risk cooking the pickup wires.  I agree with Dale, I didn't see much flickering when I tried that circuit.  Since I run just command, I don't actually use that scheme, I just use a bridge rectifier across the 18V from the track.  I came up with that for folks that run conventional, since they don't have as much track voltage to work with.  However, if you have flickering, the cure is a larger capacitor.  Here are some parts that will work in that circuit, I picked 1000 uF caps for a little more hold time.

 

CL2 - http://www.mouser.com/ProductD...fDsdbv7CfbaiDKVaw%3d

 

1000uf CAP - http://www.mouser.com/ProductD...1iNnMtp06dqSFit8U%3d

 

Diode - http://www.mouser.com/ProductD...UXCJI7Y4lo311UlJRhyh

 

Gunrunnerjohn,

 

Thank you for the above.  Now I feel comfortable building this.

Piece 'o cake.   Just build one and do some bench testing and make sure you're satisfied with it.  What I did for a group of passenger cars is build all the little modules with bridges, caps, and regulators on small cardboard squares (hot glue), then test them and finally install them and the lights in the cars.  Once you do one, the rest will go very quickly.

 

Note that if you run only command mode, I don't recommend the voltage doubler, I'd just go with a bridge rectifier, the cap, and the CL-2 regulator.  The voltage doubler is good if the input voltage is between 6-14 volts, it allows you to have lighting a low speeds conventionally.

1000 uf usually eliminates flicker in most all cases. In tight spots it may be difficult to fit it in.  Another source is www.allelectronics.com

 

I run conventional and wire the LEDs individually,not in series of 3 with the strips. If doing it that way a single CL2-n3 chip drives each LED or a 7805 regulator circuit is used so a voltage doubler is not needed. Using the 7805 circuit and super capacitors the car will remain lighted a minute or so after power is removed.

 

Dale H

Thanks again!

Some MTH Heavyweights I upgrades to LED - Before and After Shots - Used the Evans Design LED's

 

Before LED Upgrade

 

 

After LED Upgrade

 

George I hope the passengers were wearing sunblock in the before shot.

 

Nice Job!

I too have seen challenges with excessive car lighting current.  I have known Jack Pierce for about 7 years...since I worked with him to get some of his models into the TCA NTTM, Strasburg, PA.

 

Jack offers a service unmatched by others to add extensive interior and exterior lighting, and table lighting with optic fibers.  I have used his service successfully for upgrading a GGD dining car.

 

I looked at Jack's lighting board along with several others.  My criteria was low current draw per car, adequate number of LEDs to light a scale length passenger car, easily adjustable lighting level and low cost.  

 

In short I decided to design and sell my own that does everything above at lower cost.  I have passed a couple of boards to Jim Barrett for his use.  If anyone has further interest, email me at ROYZTRAINS@aol.com.  My boards were first offered at the Oct York show.

After reading through this topic multiple times, I just wanted to make sure I am ready to order all that I need.

 

I can use the above circuit to power up 6 of the LEDs that come on these rolls that are available through eBay

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&Item=150571299400

 

or Amazon http://www.amazon.com/Flexible-LED-Ribbon-LEDwholesalers-2026ww-31k/dp/B002QQ48TK/ref=sr_1_fkmr0_2?ie=UTF8&qid=1319738373&sr=8-2-fkmr0

 

And I should be able to use this in cars that I am running conventional and also with DCS, but I should add a 22uH choke in between the "Pickup" and "CAP C1" in the above circuit for DCS operation, as well as the heatsink referenced for the CL2.

 

Parts:

1 - CL2N3-G per car

http://www.mouser.com/ProductD...fDsdbv7CfbaiDKVaw%3d

 

2 - 1000uf electrolytic capacitors per car http://www.mouser.com/ProductD...1iNnMtp06dqSFit8U%3d

 

2 - 1N4005 diodes per car

http://www.mouser.com/ProductD...UXCJI7Y4lo311UlJRhyh

 

1 - 22uH choke per car

http://www.mouser.com/ProductD...PHl1FCPZucit6Q%3d%3d

 

At this point, I am only running my MTH subway in DCS and all others in conventional using the DCS variable voltage terminals or TMCC in conventional mode. I do want to be able to be flexible should I want to run any car on any of my loops.

 

Thanks so much for all of the info. I posted initially on the Subway forum, and somebody directed me to this topic.

Rrgarding the voltage doubler circuit as described above.  You will need a CL2N3 for each segment of the LED strips you referenced (quoted as around 35ma per each 3 LED segment) from eBay.  Note that voltage doubler circuits are generally not very efficient for current output...hence their reference to voltage doubler.  I have built LED lighting board with and without the 22uh choke...didn't notice any difference with DCS.

 

 

From my experience, one CL2 per 3-LED segment is too much brightness.  I have run up to 5 3-LED segments from one CL2 with good results.  Experiment before you build a bunch!

If you want an efficient voltage doubler use a bridge rectifier and 2 capacitors. Hook one cap minus to minus on the bridge. Hook the second capacitor + to + on the bridge. Hooked the remaining 2 leads to either one of the ~ terminals. having said that you are putting a lot of voltage on the components,some which are rated at 35 volts.

 

Dale H

Dale, the fullwave bridge yields exactly the same circuit.  Two of the diodes are always reverse biased and contribute nothing to the bridge's operation.  Are you suggesting otherwise, or are you just saying this is just a convenient connection method?

 

Each capacitor still sees only the peak of the AC voltage - about 25 volts for 18VAC.

My experience mirrors Dale's, no way you want all those LED's at full intensity!  You'll be trying to find your sunglasses every time you run the trains!  I used one CL2 (20ma) for a strip of 12 LED's (4 segments), and that's marginally too bright in the cars I did.  I toned it down for the next set.

Thanks for the replies. I am assuming that placing the choke between the "Pickup" and "CAP C1" for DCS operation is correct?

 

I did come up with a few more questions that hopefully someone can clear up.

 

1. Are the LEDs on these rolls in groups of 3 in parallel or in series? Does it make any difference with gunrunnerjohn's CL2 circuit?

 

2. At approx. 5-6 VAC track power, will this be enough volts to light the 6 LEDs?

 

3. Using the 2 diodes as pictured in the circuit would be cheaper than using a bridge rectifier. Would the bridge rectifier be better? I am looking at doing about 50 passenger cars and about a dozen cabooses, so cost is a factor.

 

4. It was mentioned that the use of a polyfuse between the 2 rollers is a good idea. Does anybody have info as to a suitable item - voltage rating-current rating? Mouser lists several in their catalog.

 

Thanks again for all the assistance. I have done several electronics projects in the past, so I'm sure I can accomplish this. But, I am just trying to learn from those of you in the know, and not try to reinvent the wheel.

The choke indeed goes on the pickups to isolate everything in the car.

 

1. The LED's are in series in each group, so there is a dropping resistor that drops about 3V and the three LED's drop 9V.

 

2. At 5-6V, you'll need to consider the voltage doubler I previously posted.

 

The two diodes or the bridge rectifier do exactly the same thing, and the diodes will probably be cheaper.

 

I use 3A ones, you could probably even go lower.  Obviously voltage rating of over 35 volts should be fine.

Hi Dale

 

the circuit using the bridge doubler is drawn and described in "Getting started in Electronics" by Forrest Mimms. Pg 102.  To quote from the book

 

"The bridge doubler is more efficient than the conventional and cascade doublers. Since 4-diode bridge rectifiers are available, it is easy to make"

 

Dale H

From my schooling earlier in the year, in case anyone else finds it useful (picture worth a thousand words, etc) closeups of the package I produced with 'gunrunnerjohn's help, for my MTH Superliners:



Viewed from the other side to show how I assembled the package during the learning phase (this was before I added the choke seen on the red lead above)


And the results:



---PCJ

I'm sure that quote refers to the component count and not true circuit efficiency.  As Dale M stated, the effective circuit is identical.

Question for the Dales.

Why is a choke necessary for DCS, and what does it do?

 

I am anxious to start converting my Rail King passenger cars to LEDs, and I have all of the components except for the choke coils.

 

This is a really good post topic. Thanks guys for sharing the schematic and diagrams. 

 

My offer to draw diagrams for electronic installations is still on the table for you electronics wizards. I will do this so they can be posted on this forum and downloaded by anyone for non-profit use.

DCS transmits it's 3.27mhz signal on the outside and center rails.  If there is a component, such as a capacitor, that shunts the signal inside the car, it will cause issues with the DCS signal.  The choke prevents the DCS signal from being affected by the shunt components in the car in question.

 

TMCC has a track and an air component, so the same considerations don't apply to TMCC.

Dale, on second look the circuits are not identical.  For the bridge circuit, each of the two capacitors is independently charged, and the voltage across each capacitor is near the peak of the sinewave.  The capacitors are being charged on alternating half cycles of the sinewave.  The load must float with respect to the input ground.  It still looks like only two of the diodes in a fullwave bridge are used.  The "bridge" must refer to the way the circuit is driving the capacitors in a balanced way, not the fact that a bridge rectifier is used to drive it.  You could do the same thing with two discrete 1N400X diodes.

 

John's circuit must be the "cascade" type mentioned in the book.  The second capacitor is charged once per cycle by current flowing through the first capacitor.  The voltage rating of the output capacitor must be the full doubled voltage- twice peak.  The advantage of this circuit would be that the ground from the source carries through to the load.  (For an LED circuit, this is unimportant.)

 

My apologies.

 

I use the bridge circuit on my racing trains.  I include a switch that changes the circuit from a conventional full-wave bridge for "slow"-speed testing to a voltage doubler.  (The poor little can motor takes a beating when I apply the doubled voltage, but it is fast - for a while.)

What's the circuit we're talking about?  Not having the book, what's the difference from the one I posted?

 

FWIW, when I started, I wanted the ground to be common, but if you isolate the output circuit, that would not be an issue.

Dale "drew it out" in words in his post a while ago.

If cost is a factor as you stated later, and you're building over 50 of these, I suggest you take a look at the LM317T regulator IC as an alternative to the CL2N3.  If you search on LM317T in the forum search box you'll pull up several threads on LED car lighting using this device.  RailRide's post above shows photos of the LM317T in action.  The LM317T is cheaper than the CL2, and while it requires one or more external resistors for a few pennies each it probably will not need that heatsink you reference so the construction time might be a wash.  I searched eBay and while there were no hits for the CL2, there were hundreds for the LM317T which is sort of an indicator of availability.  The LM317T is also adjustable via the resistor(s) which might apply to the comments about the fixed-output CL2 being too high (bright).

 

Is there something special about those $3 per 1000uF cap you selected?  That's pretty spendy and I'd think you could get these for less that 50 cents in small quantity.

 

Stepping back a bit, a few years ago when the topic of LED lighting came up, the white LEDs were maybe $1 a piece.  With these 3m strips, the LEDs are pennies a piece.  That said, another idea is to use the strip but bypass 2 of the 3 LEDs per segment so that you can drive the strip with, say, 4V (instead of 12V).  The strips are very narrow so if you need more light you could run a 2nd strip in parallel with the first with the active LED offset for uniform car lighting.  You still take advantage of the compact packaging of these LED strips but eliminate the need for the doubler circuit and those large caps.  So even "wasting" 2/3rds of the LEDs, the LED cost per car will still be 20 cents or so.  The LM317T could be used in this application or Dale has a blog somewhere that describes how to do this with IIRC a 7805 regulator chip (also cheaper than the CL2).

I agree with the LM317T, it's great for higher power and the ability to adjust intensity.  Here's some 1000uf Capacitors at 35V for a lot less: Kemet ESX108M035AK2AA

 

If you want 50V, here's the same one: Kemet ESH108M050AM7AA

 

 

I'd rather use all the LED's and use the doubler.  Also, if you want to drop the voltage required a little, you can jumper out the little resistors for each group, and still retain all the even illumination of the multiple LED's.