Dimming passenger car lighting - alternative to LED

Well, obviously I have to recommend the LED replacements!

Probably the easiest non-LED fix is to simply add a series diode between the pickups and lighting.  Obviously, this still requires taking the cars apart.  In truth, I don't see any "easy" way to dim the lights without taking the cars apart.

One issue with the diode is you should alternate the orientation of them in a passenger car set so you don't introduce a DC voltage offset on the tracks.  This is especially important for conventional running as you'll get either horn or bell all the time.

Since you pretty much have to take the cars apart anyway, why not do the LED lighting.  You get vastly lower power consumption, (less than 10% of incandescent), no flicker, and intensity adjustment.  Also, with the LED strip, you get much more even lighting throughout the car, no hotspots under the bulbs.

A modest demurer:

Taking apart 90 passenger cars, ripping out the incandescents, and installing LEDs sounds like a lifetime project. Some cars are an absolute beeoytch to take apart. There should be a way to accomplish the job from the bottom of each car.
Some folks (raises hand) do not find the electronical side of the hobby all that much fun. Especially as I read and reread the woes of many on this forum. Although I am eternally grateful for GRJs wisdom &c..

Well, trying to sky-wire this from the bottom of the car will be a major kludge, so I don't recommend that approach. 

If it was me I would not put any kind of kludge with any device under or in my cars . Diodes clip one side of the AC, thus cutting power to the lamps in turn diming them. Even this will generate some heat. Heat = amps and amps = voltage drop. LED's are Diodes but they generate a more efficient light then Lamps and diodes.

I used Johns diode lighting and it works great!

With a ninety car project I would ask John for a bulk discount and he is always available for solid advice.

Now get busy having some fun becoming the best LED transition guy on the site.

You must have good, even power on your layout so not to have problems with all those bulbs.

I have to guess that you don't run all ninety the same amount? Maybe you could divide the job into sections starting with the ones you run the most?

I sure wish that all the manufacturers went to LED lighting much sooner than they did. They draw so much less and no heat issues. Even so, I find myself inside of many early cars for upgrades anyways. I can't stand flickering lights!

Hmmm, I think I'd put tint on the windows before I put up with the early LED cars flickering!

breezinup posted:

This is probably a question for GRJ or anyone else with a background in electronics. I have over 90 passenger cars (how did that happen?), all with incandescent lighting. I'd like to dim the lighting in the cars. I don't have the time (or patience) to take them all apart, rewire and install LED lighting, and then reassemble them.

I'm not well versed in electronics, so was wondering if it would be possible to attach a small rheostat (if anyone makes them) to the bottom of the cars, and wire it into the wires from the roller pickups. As an alternative, would it be possible to add resistors to the roller pickup wires? It seems either one of these methods would be a lot easier than doing LED conversions.

This may have been previously discussed, but if so, I missed it.

Disconnect the wire going to the truck pickup and put a diode in series. Do each truck with the diode pointing the same way as the other truck. On the next car, point the diodes the opposite way, and so on.

That will dim the lights without taking the car apart.

rex desilets posted:

A modest demurer:

Taking apart 90 passenger cars, ripping out the incandescents, and installing LEDs sounds like a lifetime project. Some cars are an absolute beeoytch to take apart. There should be a way to accomplish the job from the bottom of each car.

Well, at my age, it could turn out to be a lifetime project!   These cars include everything from baby Madisons to 18" aluminum jobs. I might get rid of some, and just selectively upgrade some of the remaining sets to LED, but it might still be more than I care to do.  

RobBoy's suggestion is the kind of alternative thing I had in mind. I suppose I could take a car and try it and see what happens. A redneck solution is to take apart the car to expose the bulbs and dab a little heat-resistant black paint on each one to reduce the light. Simpler than redoing the lighting, although some car disassembly still required, and you don't get the benefits of LEDs, of course. Actually, I've done that in the past on some interior lights like overly bright engine cab lights. Ultra simple, and it worked fine.

breezinup posted:

A redneck solution is to take apart the car to expose the bulbs and dab a little heat-resistant black paint on each one to reduce the light. Simpler than redoing the lighting, although some car disassembly still required, and you don't get the benefits of LEDs, of course. Actually, I've done that in the past on some interior lights like overly bright engine cab lights. Ultra simple, and it worked fine.

If you're taking the car apart, you've already done the hard part of the job, so it escapes me why you wouldn't simply go the whole job.  You'll spend half (or more) of the time, and end up with a mediocre result.

Even with more difficult cars, I can knock one out in an hour or less, so I don't think it's a "lifetime" unless you're worried about living past next week!

The simple MTH Premier cars I can have LED's up and running in the coaches in around 15 minutes.  Observation and dome cars take longer.

Tom, I have to agree with GRJ here.  Over the last year or so I’ve changed over 40 cars to leds using his modules and a DIY variant.  Hardest for me were the Williams streamline aluminum.  Sliding the chassis and trucks past the rolled under shell was a bear.  But our favorite series,(6-15311,12,13,17) were pretty easy, and the 18” with streamline lighting even easier.  You eat an elephant one bite at a time.  It won’t take as long as you think.  And all of a sudden your eight car Super Chief with LABC high smoke goes from 8.5 amps to 3.5.  Give it a whirl...  

Alright, John, I surrender.   Thanks for your information. Very helpful as always. Was just curious if there were any shorter distance between two points, but it doesn't appear any other alternatives will offer a simpler route. Don't want to do anything if to "sky-wire this from the bottom of the car will be a major kludge."  I have enough kludge around here already.

Thanks, all , for your views. (John, get crackin' on development of those rheostats. ) Ted, thanks for  your input. Interesting you mention that series of cars, including those CZ cars, as your favorite. Mine as well. I have 4 sets from that series - terrific cars for 15" fans. Glad to hear they're relatively easy to convert. 

As an aside, regarding your comment about the Williams aluminum streamlined cars, and that "sliding the chassis and trucks past the rolled under shell was a bear," I haven't taken any Williams apart, but have done similar MPC-era Lionel cars. Maybe it isn't possible with the Williams, but after doing exactly what you described with a Lionel Illinois Central aluminum set, I discovered that the way to do it is to remove the trucks first. Very easy to do with the Lionel cars. Without doing that, the truck sides rubbed against the rolled under shell portion, as you described, and it was indeed a real bear. Lifting off the trucks before sliding the frame out of the shell made the process a cinch, though.

banjoflyer posted:

Well this'll sound silly but one method is to use a higher rated voltage bulb to get a dimmer lighting output. Think 24 volt bulb used in a 12-18 Volt circuit. It should give out less light than an 12 or 18 Volt bulb..........

 If you are unhappy with your car lighting take the plunge and upgrade the ones you want to keep.

Thanks for your idea. However, many of the cars I have use light strips with multiple bulbs soldered to circuit boards affixed to the top of the car, so it's not really possible to replace the bulbs. Your comment about taking the plunge and upgrading the ones I want to keep is right on the money, though, and is what I'll be doing. 

breezinup posted:

Alright, John, I surrender.   Thanks for your information. Very helpful as always. Was just curious if there were any shorter distance between two points, but it doesn't appear any other alternatives will offer a simpler route. Don't want to do anything if to "sky-wire this from the bottom of the car will be a major kludge."  I have enough kludge around here already.

Some K-Line cars also need the trucks removed to slide the chassis out of the aluminum shell, not an uncommon situation.

Sorry I had to take the large hammer out to drive the point home, but sometimes the shortcut you consider is the long way home.  

I just hate to see someone do half-way measures and end up with something not much better than when they started.  I figure if you're going to do the work, might as well reap the benefits.

FWIW, and to BanjoFlyer’s option of increasing the bulb voltage, this heavyweight car from a ‘97 set, the previous owner put 4-24v bulbs in to dim the output.  I superimposed a before and after in the photo.  I used warm white led strips painted with Tamiya X26 clear orange.  Some go ahead and use amber leds.  YMMV on your color taste.  Something else(warm white) installed in the streamlined, and still more blueish on the newest Amtrak sets simulating fluorescent lighting.  Many options out there to try.  Good luck.

If it makes you feel better about the LED upgrades, the hardest part of the job (in my opinion) is taking the car apart and reassembling.  The LED's and the control electronics can be prewired if you have a group of similar cars and simply need to be attached to the ceilings and tapped into the existing power wiring.  I used John's convertor boards and while they may not be the cheapest approach, they certainly saved me quite a bit of time which was well worth the money in my opinion.