# Taking the leap to DCC and question about LEDS.



## 2genflyers (Jan 14, 2013)

Question(s) about DCC and lighting.

This message goes out to those of you who KNOW about electronics(WVGA & Gunner, etc):worshippy:... and NOT the "pretenders".
I'm an S-Scale/Flyer guy, (ok, stop laughing please) I'm looking to add some reliability and realism to my passenger cars. Currently they utilize a single floor/center-mounted incandescent bulb, which "over-exposes" the center of the train but leaves the ends "in the dark". Additionally,even with very clean track and wheels I get periodic flickering/outages. That's the nature of the beast with 60+ year old cars.

I'd like to switch to 3-5 LEDs (3mm) spread across the inner roof for more realistic light distribution. I understand that LEDs need a DC current flowing in one direction (hence the longer/shorter leads). DCC causes a problem in that the current can alternate (auto-reversing track segments) and a host of other situations. A bridge rectifier and resistor are needed to solve this problem and to insure decent bulb life. I've found these, prepackaged at a number of retailers, so that part of the problem is solved.....

...However...

And now for the question...Can I add a capacitor to this circuit in order to eliminate current interruptions? And if so, what specs would you suggest on the capacitor and where in the circuit do I add the capacitor?

Now that I've revealed how utterly noobish I am with things that "spark".... and once you've stopped :laugh:, please feel free to correct EVERYTHING I've just said! You won't hurt my feelings!

Any other tips are greatly appreciated.


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## wvgca (Jan 21, 2013)

You might check out some of the posts on "Passenger Car Lighting", while these are directed towards O scale, the basics are the same .. doesn't matter much to a bridge whether it's fed AC or DCC ...


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## santafealltheway (Nov 27, 2012)

I bought a roll of strip LED's from china on ebay... they light up regardless of which way the car is turned on the track.


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## gunrunnerjohn (Nov 10, 2010)

Those strips are polarity sensitive, so for HO you'd certainly need a bridge rectifier at least to insure they light at either polarity.


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## CTValleyRR (Jul 26, 2014)

2genflyers said:


> This message goes out to those of you who KNOW about electronics(WVGA & Gunner, etc):worshippy:... and NOT the "pretenders".


That's kind of rude. At least it seemed that way to me. I only know of one person on these boards who would reply with questionable knowledge. He would have copied and pasted an answer that he didn't completely understand from some other website and passed if off as his own knowledge. That member is currently banned (although if history is any guide, he'll be back with another screen name and proxy server IP address in about ten days).

Really, the question isn't that hard, and you haven't yet delved into any topic that would take a real expert to answer.


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## 2genflyers (Jan 14, 2013)

CT... I simply didn't want misinformation which would lead me to make an expensive mistake so I called for advice from WVGA and Gunner. You may have a PhD in EE... so I'm sorry if I left you off the list. WVGA and Gunner seem to be knowledgeable and helpful so I reached out to them. Isn't that one of the purposes of the forum? I clearly explained my lack of understanding of things that "spark", and was genuinely asking for help. Sorry my level of understanding and question did not represent an "expert" level question... but to me it's beyond my understanding, so it might as well be "expert". "Bad" advice can come at ANY level.

Regarding being "rude".... I think that's the pot calling the kettle black... given what I've read in MANY other posts about the individual in question. Me calling him a "pretender" PALES in comparison to the paragraphs written. Frankly some on this forum have gotten down-right aggressive on that issue...BUT it might be deserved, I wouldn't know as I'm a noob. What I DO know is that I didn't want HIS help on something that already has me confused. 

WVGA - Many thanks for the tip to do a search. Found an outstanding post from L0sts0ul.


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## Tom_C (Jan 8, 2016)

2genflyers said:


> WVGA - Many thanks for the tip to do a search. Found an outstanding post from L0sts0ul.


Please share the link. I know my way around a soldering iron but still interested to read what you found.


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## 2genflyers (Jan 14, 2013)

Here you go Tom....
http://www.modeltrainforum.com/showthread.php?t=108729&highlight=passenger+car+lighting


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## gunrunnerjohn (Nov 10, 2010)

One thing to note, for an HO application, you'll want a solution that includes a bridge rectifier to allow the lights to function no matter which polarity is applied. It would suck to only have the cars lit going one way on the track.


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## 2genflyers (Jan 14, 2013)

Gunner... can you recommend some specs for Tom and I?


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## 2genflyers (Jan 14, 2013)

*gunrunner*... sorry.


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## gunrunnerjohn (Nov 10, 2010)

If you're looking to roll your own, I'd recommend something like this. This gives you flicker-free lighting with constant intensity. This works for AC or DC power on the tracks. There are many ways to skin this cat, this is just one of them.


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## 2genflyers (Jan 14, 2013)

Thanks much. They are available through online suppliers.... but what's the fun in that. Besides, how is one to learn anything. And yes, I have a fire-extinguisher in the workshop!


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## gunrunnerjohn (Nov 10, 2010)

Well, if you want something ready made, I designed and built lighting modules. Variable intensity, flicker free, and they even include a choke for MTH DCS compatibility.

These are sold through Henning's Trains, Tel: (215) 362-2442


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## CTValleyRR (Jul 26, 2014)

2genflyers said:


> CT... I simply didn't want misinformation which would lead me to make an expensive mistake so I called for advice from WVGA and Gunner. You may have a PhD in EE... so I'm sorry if I left you off the list. WVGA and Gunner seem to be knowledgeable and helpful so I reached out to them. Isn't that one of the purposes of the forum? I clearly explained my lack of understanding of things that "spark", and was genuinely asking for help. Sorry my level of understanding and question did not represent an "expert" level question... but to me it's beyond my understanding, so it might as well be "expert". "Bad" advice can come at ANY level.
> 
> Regarding being "rude".... I think that's the pot calling the kettle black... given what I've read in MANY other posts about the individual in question. Me calling him a "pretender" PALES in comparison to the paragraphs written. Frankly some on this forum have gotten down-right aggressive on that issue...BUT it might be deserved, I wouldn't know as I'm a noob. What I DO know is that I didn't want HIS help on something that already has me confused.
> 
> WVGA - Many thanks for the tip to do a search. Found an outstanding post from L0sts0ul.



Well, I meant rude to the rest of us. If that was a cheap shot at ED-RRR, or whatever he'll be calling himself next, then no worries. For me, I have only been *intentionally* rude to two people here: ED and some guy trying to set up links to his Amazon Associates site. And yes, I freely admit that the key word there may be "intentionally".

I certainly don't have a degree in EE, and when it comes to actually modifying a circuit board, I'm as lost as the next guy. DCC, capacitors, and LEDs is pretty basic stuff, though. Lots of folks could have pointed you in the right direction there, EE's or not. It sounded to me like you were deliberately excluding all but the very elite, so if not, no harm done.


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