HOW TO--COACH LIGHTING.

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mortyfootball
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Post by mortyfootball »

Good to hear Greg.

Shaun
Currently on the rails with my camera
Mitzibitzi
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Post by Mitzibitzi »

I was just reading through this thread and noticed the complaint about the lights going off/flickering when passing over points.

There is a very simple cure for this.

When using LEDs, simply connect a 220uF 35v BIPOLAR electrolytic capacitor between the two pickup wires. It's important that you use a bipolar cap, or it won't work when the train is run in reverse and will probably blow the capacitor, as well. The LEDs should be connected in parallel.

To do it with grain of wheat bulbs, you need to run 4 in series (NOT parallel) and also put a 220-ohm 1/2W resistor in series with the chain, then connect the bipolar cap as before.

The only disadvantage to using the G.O.W bulbs with this is that if one bulb blows, none of them will light up.

For those of a penurious bent, such as myself, the requisite bipolar cap can often be scavenged from old PC motherboards. It's usually easy to spot, it has 220uF (470uF will work just as well) printed on it, is usually near the power-connector socket and doesn't have markings to indicate polarity.

However, if you want/need to buy them, the type you want is shown on this page:

Linky

Don't bother with the 16v rated ones, the back EMF from the motor during starting will muller them in short order.

Now for the caveats (there always is one): If you do this and run it on a system with DCC, your DCC won't work properly or perhaps at all. So strictly DC only. There are ways to make it work with DCC but they're too complicated to be worth the effort. I'd have switched to NiMH batteries in each coach a long time before I'd go to the trouble.

Also, if your DC controller uses current feedback sensing to improve slow starting (most Gaugemasters and similar high end units probably do), then it may affect the operation of that system. My feeling is that it should just mean a slightly more gradual start from a dead stop, which you might like, but I'm not willing to stake my life on it without trying it first.

For what it's worth, I prefer the rechargeable battery method myself.
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sanctuary
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Post by sanctuary »

Mitzibitzi wrote: For what it's worth, I prefer the rechargeable battery method myself.
I'm no expert hence my question to you Mitzibitzi, would it be possible to use the battery charging method and do as above re capacitor but use the battery as the capacitor in other words charge the battery from the track.

Thinking about it as I type I realise a couple of problems back feeding from battery to track would a diode solve this.
Reverse running wrong polarity across battery make some kind of rectifier work. I'm sure there may be more problems but could they be overcome and what size battery would be needed for the short stops at stations.
Tight Lines Aidan

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Mitzibitzi
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Post by Mitzibitzi »

In theory, yes, you could. You'd have a fair bit of trouble with the current the batteries would want to draw if they hadn't been charged for a while, though. Your controller certainly wouldn't enjoy it, so you need to fit a proper charging circuit inside the coach with the batteries.

The method I like best, as it involves no effort, is to replace the buffers on both ends of a rake of coaches with metal ones and use them as positive and negative terminals. Also add a wire that links all the coaches together, preferably with a plug, so they can be seperated easily. I've seen it run through the corridor rubbers on rakes that use those and you can't even see it.

Then you can run the rake hard up against a set of buffers (with metal faces, of course) on a storage siding and it charges from a proper battery charger while standing. Can even leave them there when you're not in, provided the charger is one of those that drops to a trickle charge once the batteries are full.

I like this best because you aren't having to handle the coaches more than usual, thus avoiding wear and tear.

I saw a beautiful example of this at an exhibition a few years ago. The rakes used authentic three link couplers to join them, which formed one 'wire' and the steam heat pipes formed the other. The lighting was so good that even some of the little overhead reading lights in the compartments were lit up with fibre-optics. And, get this, there was a guy in a suit leaning out the doorway window of the front coach smoking a faintly glowing cigarette. Incredible work. Shame it was GWR, but you can't have everything (flame suit on :D )
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Ironduke
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Post by Ironduke »

You could fix that with a constant current source but most batteries don't like being kept on a continuous charge. Even the ones you're supposed to be able to charge all the time (like lithium ion) have a limited lifespan when you use them this way :^(

If you really want true constant lighting you can
A. Get DCC or
b. introduce some electronics - an AC signal suprimposed on the DC voltage and filtered out in the locos so the motors don't heat up.
Regards
Rob
waz
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Post by waz »

Hi Chaps !!!!

First up, sorry, I havn't been keeping an eye on this thread, to be honest I'd forgoten about it.

So, Greg if you get back to read it--- great stuff and it's easy and effective isn't it. Bet your coaches look great in subdued light I know mine do.

Thanks to all recent contributors. Unfortunatly I am not an electronics whiz but then I suppose those of you who are don't realize it.

It was because I'm not that I took the Rupert the Bear route for the lighting. Still working a treat, by the way.

Many thanks to you all.

My Best Regards

BILL.
Mitzibitzi
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Post by Mitzibitzi »

Ironduke wrote:You could fix that with a constant current source but most batteries don't like being kept on a continuous charge. Even the ones you're supposed to be able to charge all the time (like lithium ion) have a limited lifespan when you use them this way :^(

If you really want true constant lighting you can
A. Get DCC or
b. introduce some electronics - an AC signal suprimposed on the DC voltage and filtered out in the locos so the motors don't heat up.
My Dad was playing around with that idea when we had the old layout set up at his house. He stuck 14v @ 12kHz on the DC line and used a little transformer inside the back (guard compartment) to drop it down to about 2.5v to run a string of LEDs through the rake and keep the charge topped up on a pair of 1.2v NiCads.

We just left the lights on when we had the layout switched off to run down the batteries and prevent memory effect. Well, that was the theory, but the current draw of the LEDs was so low it would take nearly 4 days for the batteries to go flat. Probably a 2.4v memory backup button cell would have been better but they were hard to get cheap back then. Pretty near free these days, of course.

The motor just had a cap across it's terminals to deck the AC, IIRC. Possibly a series resistor, too. Not too sure.

The main drawback of it was the need to have the Cl.25 and it's rake permanently joined, though I suppose we could have plug and socketted them together.

It's a lot of trouble to go to, though.
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sanctuary
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Post by sanctuary »

I'll go down Bills method when I'm at the stage of lighting the coaches, the other methods have to many side affects re my electronic controls, or just use a battery with LEDs. Thanks for your reply Mits and Iron.

PS Thank you Bill for the article.
Tight Lines Aidan

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RAF
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Post by RAF »

Great article and responses, I need to re-read it thoroughly before attempting my pullmans... If simplified it would make a great article section on the main site.

If I wanted to have 4 bulbs in each carriage then I assume I would need to wire 4V bulbs in series to equal 16V?

The other idea was that if I used much lower voltage LED's I could make a longer string that totalled 16V and spread them across all five carriages and permanently connect them, would that work?
oreomonster

Post by oreomonster »

This is a good article, I will tryand give it a go on some coaches that I have and let you know how I get on.

Thank you for the idea :D :D
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Ironduke
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Post by Ironduke »

RAF wrote:Great article and responses, I need to re-read it thoroughly before attempting my pullmans... If simplified it would make a great article section on the main site.

If I wanted to have 4 bulbs in each carriage then I assume I would need to wire 4V bulbs in series to equal 16V?

The other idea was that if I used much lower voltage LED's I could make a longer string that totalled 16V and spread them across all five carriages and permanently connect them, would that work?
No you cannot run series LEDs on a varying voltage source. Say if you had 2.2v LEDs then you could run 7 in series to make 15.4V, under 15.4V they will just turn off.. over 15.4V they will start to burn out. better off using 7 LEDs in parallel with a series resistor each. Or even better a constant current source so they have the same ammount of brightness over the whole voltage range (above 2.2+whatever the ccs drops that is).
Regards
Rob
mumbles
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Post by mumbles »

does anyone want to light my coaches for me!
no
oh well
looks like i'll have to try for myself then! :D
RAF
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Post by RAF »

Ironduke wrote:
RAF wrote:Great article and responses, I need to re-read it thoroughly before attempting my pullmans... If simplified it would make a great article section on the main site.

If I wanted to have 4 bulbs in each carriage then I assume I would need to wire 4V bulbs in series to equal 16V?

The other idea was that if I used much lower voltage LED's I could make a longer string that totalled 16V and spread them across all five carriages and permanently connect them, would that work?
No you cannot run series LEDs on a varying voltage source. Say if you had 2.2v LEDs then you could run 7 in series to make 15.4V, under 15.4V they will just turn off.. over 15.4V they will start to burn out. better off using 7 LEDs in parallel with a series resistor each. Or even better a constant current source so they have the same ammount of brightness over the whole voltage range (above 2.2+whatever the ccs drops that is).
Thanks for the info, was trying not to bother with resistors ect, so might resort to the the massive collection of spare xmas light bulbs I have. Can I run those in series as posted in my previous post?
sol
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Post by sol »

Irondukes' comments about LED's not turning on if below 15.4 volts ( for 7 of in series) - well I run LED's that are nominal 2.2 volts at about 1.5v & they work OK - current is down a bit as I use a higher value resistor - makes them last longer; it also protects them if the mains power spikes a bit & increases the LED voltage. The amount of light from the LED is still suitable for normal use.
regards
Ron Solly
Taw Valley
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Post by Taw Valley »

Mitzibitzi

i'm very interested in the whole metal buffers etc ( although im sure i could do something like that guy and have my hornby couplings as one "wire" and steam heat as another "wire or something simular ....

when banging hard up agaisnt the buffer stops on the track would this just be the end of 2 wires touching another 2 wires ( buffer to buffer) and going stright to a trickle charger?

also would it make sence to make small connectors for each coach so they can still be shuntted into new conbonations and just hook the connections back up once in the fiddle yard?



lol theres so many ideas from everyone on here that i want to have them all on my layout if its ever built but i just dont have the time / money / or know how to do half of it lol . although i love asking to see if i can still do it !!!!

also hello tom :D

wow , i should go to bed .
night all

* thinks who the f*** is up at this time of night so is really talking to himself , also things how good he was not to swear and to blank it out :D *
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