Large Scale Central

Loco headlights: bulb or led?

Electronics
#1

I’m sure this has been covered before but…

Having converted my Bug Mauler to battery, I have to redo the headlight wiring, which must be linked to the no-longer-used track pickups because the light doesn’t work. Anyway, while I’m in there, should I be converting to LED? If so, where do ya get 'em (Radio Shack?) and what kind? Also, what else do I need (resistor, diode, etc)?

Will the light come on almost immediately (before the loco moves) stay on, and be of constant brightness? By Rule Whatever, is the loco headlight supposed to stay on all the time, or only when the loco is moving forward?

And what about the tender “headlight.” I’m guessing it should light only when the loco reverses. So do we put a diode in there?

#2

Check on ebay for LEDS. Ralph sent me a link to a LED supplier and I think it was ebay. I got about a hundred of them for about 5 bucks. For headlight on a steam loco I think your better bet would be a smaller incandescent bulb. It’s a softer, more yellowish light then a LED. But I’ve heard you can paint a LED to give it that color.

My headlight comes on a soon as the engine is turned on and stays on until I hit Reverse, then the tender light comes on. That’s the way it’s wired into the RX board. Whether there’s a rule for that I dunno. It just tells me which direction it’ll go when I hit the “Go” button…:wink:

#3

Battery power means you have voltage present all of the time, so lights can be on all of the time without waiting for enough track voltage to turn on. Also the light is constant brightness because the voltage is constant, not changing with track voltage.

If you are using a RailBoss system (and I mention this only because I suspect you may be) you can wire LEDs directly to the Forward/Reverse lighting outputs without the need for an external resistor (no calculations needed!). The RailBoss has a constant current output specifically for use with LEDs. You can of course also use the same outputs with lamps and your battery voltage as the supply. Just make sure the lamp voltage matches the battery voltage or you will be back to using resistors again.

#4

Yeah, Del, I thought about just tapping into the battery input terminal, which would mean the light would stay on all the time. No problem with voltage either, since the battery puts out only 14.2 volts, which is what my stock bulb can handle (prolly more, ‘cause on track power I’m sure there were moments when I was pumpin’ 18 volts or more).

Now with an LED, I guess I’d have to use a resistor, right? If that’s the case, I mat just stick with a bulb.

What’s RailBoss?

#5

Sorry. I thought you had purchased one. RailBoss is a family of battery R/C controllers. See my web site for details. www.GScaleGraphics.net

#6

You can use a 1000-ohm resistor with the LED and be fine. I’ve converted almost entirely over to LEDs for my lights now, save for a few passenger car and caboose lights that are too problematic to switch over. For LEDs, look for strings of “warm white” LED Christmas lights. You can usually get them in the post-Christmas sales for around $5 for a 50 LED strand. Two of those puppies and you’re good for quite some time.

Depending on my loco, I’ve either got the headlight tied directly to the battery power (so I can tell if the battery’s on or not) or to the headlight or accessory output of the controller, so I can turn it on and off. On those locos, I have a cab light or other light that’s on with the power.

Later,

K

#7

Always use LEDs! This is the 21st century: we don’t need vacuum tubes in trains!

#8

LEDs!!! No heat, low power use, last forever…

#9

LED’s are directional and are great for head lights.

However, I do not like them for the 3 sided marker lights as the incandescent bulbs light up all 3 lenses evenly (Caboose lights for one). Sometimes old technology will always work.

#10

LEDs don’t have good dispersion unless you buy the 180 degree surface mount ones.

The 3mm and 5mm do not make good cab lights, nor are they usually good for number boards.

Greg

#11

All the lights on this engine are the same 3mm warm white SB LEDs with different resistors

#12

Guess what, Joe?
Steam engines used oil or…a dynamo…as in electric.
They used incandescent bulbs.
I have yet to find even a warm white LED that gives me that colour.
ALL of my steamers get GOR bulbs, 14V, and I can read waybills by the light of the silvered reflector…and see switch positions…and to switch cars.
I am trying to think if I may have mis-spoke…but to the best of my knowledge, not one of my steam engines uses an LED for lighting.
Of course, you could always buy a Bach 45-tonner have have carbon-arc blue headlights, just to be different…

#13

The early warm while LEDs had a yellow color if you turned them down with a larger resistor. These newer ones are closer to a pure white. They actually act like headlights and light up in front of a train like a real one. Of course, I’m talking about a modern train with a bulb for a headlight.
If your running battery especially and worried about battery life, I would think you’d like the results with the right LED and resistor combination.

#14

A Grain of wheat headlamp has minimal if any effect on a battery pack. I had this discussion with a friend before. My K27 will run for 6.5 hrs on a full battery charge on rollers lights off. With it’s lights on it ran for 6hrs 20 minutes. Granted I’m not the best time keeper but that’s pretty durn close. It’s also kind of boring…

In my opinion LEDs don’t look good in steamers at all. Sanding, painting or resistors they still look like LED lamps. They do look great in a diesel though.

As for life span, My station is outdoors from the time the snow melts till if comes back down, about 7 months. Everynight at dusk the lights come on, in the morning the go out, all grain of wheat. After 5 years I just had one go out.

By the way Joe, that’s a sweet looking loco!

Terry

#15

I go along with Dave and Terry, on this. I have changed all my locos (steam & gas/mech) over to bulb from LED for the reasons stated. All are battery and I really never run a single locomotive long enough for lights on or off to make any difference to charge life. To run any single locomotive 4-5 hours straight, well I don’t have that kind of time, usually takes 2-3 sessions to drain a battery then we just drive out another loco to take over.

#16

Terry Burr said:

A Grain of wheat headlamp has minimal if any effect on a battery pack. I had this discussion with a friend before. My K27 will run for 6.5 hrs on a full battery charge on rollers lights off. With it’s lights on it ran for 6hrs 20 minutes. Granted I’m not the best time keeper but that’s pretty durn close. It’s also kind of boring…

In my opinion LEDs don’t look good in steamers at all. Sanding, painting or resistors they still look like LED lamps. They do look great in a diesel though.

As for life span, My station is outdoors from the time the snow melts till if comes back down, about 7 months. Everynight at dusk the lights come on, in the morning the go out, all grain of wheat. After 5 years I just had one go out.

By the way Joe, that’s a sweet looking loco!

Terry

I can understand that. I really went LED when my old HO engines would melt if the bulbs were left on too long. If you ran long sets of passenger cars and noticed how much power you’d lose to bulbs, you might start looking at them closer. They have better color choices out there and tone down quite well if installers would take the time to size the resistor to get the desired yellowish color hue. There are all kinds of dispersion patterns available now.
BUT!, One grain of wheat bulb, is not a big deal.

#17

Yeah, but we aren’t talking passenger cars. Good idea on them…IF you light them. All the examples shown are diseasemals, yet young Joe has a…Bug Mauler!

I have seen writeups on painting the backside with some special Tamiya paint to get the colour right…and it never works.
I started doing it when all you got from Botch was wimpy yaller LEDs you couldn’t make any brighter. Tried. Got down to about 50 ohms before the flashbulb went off.

I get 14V GOR bulbs (big, same size as the LED’s used in most LS headlights) from a Lionel parts source. I don’t think I’ve lost one yet. Used to use Miniatronics 12v GOW bulbs…occasionally, 10 years or more out, we’ll lose one.

TOC

#18

Curmudgeon mcneely said:

wimpy yaller LEDs you couldn’t make any brighter. Tried. Got down to about 50 ohms before the flashbulb went off.
TOC

If anyone wanted to make the LED brighter, you could use the LED voltage calculator to figure out what size resistor to use. You can’t go smaller because too much voltage will be passed, as pointed out here. You can go larger to dim the LED when it’s too bright.

#19

Calculating LEDs is easy. http://www.barefootelectronics.com/led001.aspx

Basicly, R=(Vsystem - VLed)/Iled