My set of SP cars have lighting which I found problematic. The two interior LED's give very bright lighting easily seen in a lighted room. But they look wrong in a darkened room, and the problem is made worse because light comes thru the sides of the cars, making them look like they came out of a furnace. A lot of painting would be needed to fix that.
I studied the main PC board, which has a regulator transistor connected thru a diode and a 22 ohm resistor to the LED's and 1 farad cap, in parallel with them. I cut the land between the 22 ohm and the LED's/cap, and tried resistors to cut the brightness to a good night level. I chose 470 ohms. I decided to make both brightness levels available, so I put a magnetic latching reed switch in parallel with the 470 ohm and mounted the two at the left side roofline above the board, snug against the plastic. Pass a magnet-works great. In the dimmed mode, nearly zero shinethru. Should work on other MTH HO cars if and when.
You could also rig the switch to just turn off the dimmed or undimmed lights. Be careful to leave the cap in parallel with the LED's; it is only rated for 2.5 volts. A side advantage of the dimmed mode is that the lighting drain per car drops from 23 to 11.5 ma. The switches are available from Demar Electronics.
Hal
Interesting. But that just seems like a lot of work. I have the entire 8 car set, plus and additional one. 9 cars total. And I really don't feel like making these modifications. They don't look that bad, enough to justify the extra work.
But I still appreciate your help posting this.
Michael
CEO- Mile-HI-RailroadPrototype: D&RGW Moffat Line 1989
Hi Motley
I was taking the cars apart for seated people anyway, so the mod didn't add too much time. If you don't ever run your train in the dark (it IS a Daylight), it may seem trivial. I also put in a decoder for the backup light.
Diode and small resistor? That sounds like an inrush limiting circuit, particularly if there is a 1 farad capacitor in there. That's a lot of inrush time if the cap is fully discharged (which probably takes a month with LEDs)
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Where are you getting your latching reed switches? Regular ones are easy to come by, but my previous source for latching ones no longer sells them.
Steamnut, they are available from Demar Electronics. Randy, yes, the lights take 10-30 seconds to turn on all the way. They also glow for about 90 or more seconds after power removal.
hdtvnut Hi Motley I was taking the cars apart for seated people anyway, so the mod didn't add too much time. If you don't ever run your train in the dark (it IS a Daylight), it may seem trivial. I also put in a decoder for the backup light. Hal
Hal,
What you did sounds really neat. I am wondering why you didn't just put in a 4 function decoder since you were putting in one for the back up light. That way you could have lighting and lighting levels controlled with your system and fewer overall components.
Richard
Richard, that would be great for the Obs car, but I didn't think it would be worth it (the reed switches are only about $2) for all the cars, so I put a reed switch in it for consistency. If only a few cars were involved, I might have considered stringing a wire between them, but I have 26 interior LED's
Micheal, with average room lighting, minimum problem. But if one darkens the room, the cars look pretty bad. I considered painting the insides of each car with something opaque, then restoring the wall colors. But this also would have required removing the windows, which are pretty well glued in. More work than the reeds. And IMHO, even without shine-thru, the lights would still be too bright. By the way, the BLI Obs car is even worse, with gross leakage around the back end, room lights or not.
How hard is it to take these MTH SP cars apart? I would like to apply figures in my cars.
How hard is it to take these cars apart? I would like to add people inside all of my cars
Thanks,
Gary
That was 18 months ago, so I am hazy about the details. The bottom separates from the side walls and top with careful prying. I think you have to remove either the cut levers or the steam pipes and couplers first. Easier and less hazardous than Walthers cars.