Passenger LEDs

[Railrunner130]

I'm trying to upgrade the lighting in a number of passenger cars. I purchased three passenger led boards from the folks in China at a good price. I figured I'd install them and consider buying more. I also figured it wouldn't take much to install. Unfortunately, there were no directions that came with them. My concern is I don't want to hook it up and blow the entire board because I didn't use resistors. I'm running straight DC on my HO-scale layout.

What do I need to look for in order to hook this up without blowing the board? I do have a resistance meter.

 

[bwells]

Do you have a link as I am interested in doing the same thing. Are there no resistors wired into the board for each LED? I'm still having difficulty picking up power from the trucks, so far I've tried 2 different methods and it really decreases the rollability of the cars, alot!

 

[Railrunner130]

http://www.ebay.com/itm/8-pcs-12V-w...l_Railways&hash=item3ccb62f308#ht_5081wt_1161

I don't know why it's showing in Aussiebucks, but here it is. There are a few different ways to purchase it.

I'd recommend going through Athearn parts to find what you need.

 

[bwells]

I've looked at those but the only problem is they need 11-12 volts to operate and I run my engines around 8 volts. I've been toying with a 11.1 volt lipo battery which can be recharged and will not flicker due to bad contact with the rails. Thanks for the link, I've bought trees from them before.

 

[bwells]

Did you figure out a way to power these? It appears each strip is made up of 6 LEDS 3 in series and then paralled to the other three. They must be 4 volt LEDS and the info says you can cut them and I assume that is on the line with 2 dots in the middle of the strip. Not sure why you would want to though. I just ordered some and plan on running them with a LIPO battery 3 cell (11.1) volts with a magnetic reed switch and a LVC ( low voltage cutout) since LIPOS hate to go below 3.2 volts per cell, really hate! Plugs between the cars is the next thing to figure out, maybe some micro plugs and one to recharge the battery. Let me know what you come up with. Thanks Brian

 

[peroni]

If you look at the strip it has a resistor between each led, so it can run on 12v and if you cut it in halves where the two pads are, you can still run both sections on 12v each.
The only problem with using leds on DC are they are polarised, which means if they work when you are going forward then when you reverse they will not work as the positive and negative have to switch around to reverse, and the positive side of the led will have a negative polarity to it. This will not harm the led because of the resistors in line with them.
I run on DCC and I bought a similar strip but much cheaper:

http://www.ebay.com.au/itm/5M-SMD-5...443?pt=LH_DefaultDomain_0&hash=item27c90d540b

These are the same thing with the resistors between each led but they have a sticky back with a peel off tape, and you can cut them where the pads are to have them any length you like, running off DCC you need a small rectifier and a cap and it doesn't matter if you go forward or reverse the polarity to the led will never change.

 

[Railrunner130]

Brian,
No I haven't gotten it figured out yet.

That strip led system looks really neat. The warm white is what would appear to be the right one to use. I'm running regular DC. How would I connect it to a power source? Is it as simple as connecting the strip with a wire and then to the powered truck?

 

[bwells]

If you look at the strip it has a resistor between each led, so it can run on 12v and if you cut it in halves where the two pads are, you can still run both sections on 12v each.
The only problem with using leds on DC are they are polarised, which means if they work when you are going forward then when you reverse they will not work as the positive and negative have to switch around to reverse, and the positive side of the led will have a negative polarity to it. This will not harm the led because of the resistors in line with them.
I run on DCC and I bought a similar strip but much cheaper:

http://www.ebay.com.au/itm/5M-SMD-5...443?pt=LH_DefaultDomain_0&hash=item27c90d540b

These are the same thing with the resistors between each led but they have a sticky back with a peel off tape, and you can cut them where the pads are to have them any length you like, running off DCC you need a small rectifier and a cap and it doesn't matter if you go forward or reverse the polarity to the led will never change.

I assume the rectifier is to change 16 volts AC to 16 volts DC but then you would need a regulator to cut the voltage to 12 like a 7812? If that is correct, it seems the best way for DCC. With DC, the lights will burn too dim if at all until 11 or so volts( not sure, I will check when I get mine). Railrunner, If you have trucks with one side metal, opposite on either end, that should do it but I'll bet you really have to put the beans to it to get it to light!

 

[peroni]

I tried just a rectifier I was running on 16.6v and the leds were much too bright as these are made for cars which is around 13.8v they will take the higher voltage for a very short time, you really need to use a 7812 voltage regulator to peg the voltage at 12v and a cap across the output to stop any flicker like when you go over a set of points.
On DC you cannot have a truck reversed on one end because the wire from the truck either positive or negative would then have to connect to the leds and they already have a positive and negative going to them, so it would end up a dead short.
There are several things that you can do, (1) turn the passenger car around when you go in reverse, (2) use a small relay to switch the power to the leds, (3) use two strips in the passenger car so that one strip lights one way and the other strip lights in reverse.