# end of track bumpers



## jlc41 (Feb 16, 2016)

I would like to add an LED to my end of track HO bumper. I have Bachmann ho bumpers. My idea is to install an LED into the bumper. Can someone tell me what size LED I would need. Am thinking I could turn it on when the turnout is thrown to allow the train on to the track in my yard. Thanks in advance.
Joe


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## traction fan (Oct 5, 2014)

*LED size*



jlc41 said:


> I would like to add an LED to my end of track HO bumper. I have Bachmann ho bumpers. My idea is to install an LED into the bumper. Can someone tell me what size LED I would need. Am thinking I could turn it on when the turnout is thrown to allow the train on to the track in my yard. Thanks in advance.
> Joe


Joe;

The most common sizes for LEDs are 5mm. and 3mm. diameter. There are much smaller ones called "surface mount" LEDs. Unless you really need a very small size, I would stick to the 3mm.& 5mm. types. You will need a current limiting resistor on each LED. A 680 ohm resistor works well with 12 volt power. Running the LED without the resistor will quickly burn it out.
I don't know the size of a Bachman HO bumper, so I can't tell you which size will fit. I don't think I have ever seen a real track bumper with a light in it. That doesn't mean you can't have them though. Some modelers, and real railroads, use short "Dwarf" signals on the tracks of train stations. These change from red to green, to let the engineer know when it's safe to go onto that track.

good luck with your project;

Traction Fan


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## Cycleops (Dec 6, 2014)

I would think the small surface mount leds would be more suitable on a small item like that. They are very difficult to work with but would look better imo.


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## shaygetz (Sep 23, 2007)

If you're using straight DC power, use a bi-color one--re/green for instance--so it will change with the polarity...green for inbound, red for out...


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## jlc41 (Feb 16, 2016)

Very good information. Thank you all.


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