I want to change the bulbs for LEDs in two Bachmann steam locomotiveS. One bulb is dead and the other is too dim to be realistic. The two locos are:
- Bachmann Spectrum 2-8-0 with a TCS DP2X-UK decoder;
- Bachmann Spectrum 4-6-0 with Digitrax DH123 decoder.
I will use Miniatronics 3mm Yeloglo LEDs.
Will a 1k resistor do the job to limit current?
Guy
Modeling CNR in the 50's
That should work just fine for you, Guy. And be sure to put heat shrink around the exposed legs of your LEDs so that they don't short to the chassis.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
The 2-8-0 at one time had light bulbs which did burn out. To my knowledge, no resistor on the PC board.
The 4-6-0 has an LED down inside the smoke box with a resistor on the PC board. Over 2k. I have this loco.
Remove the PC boards and hard wire with a 1k, 1/4 watt resistor.
Not easy to change the resistor on the PC board.
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
richg1998,
How can I have access to the LED inside the smoke box of the 4-6-0? It is the one that is burnt out.
I could be wrong but the front boiler plate is probably a press-fit and will pull out, if coaxed. Some come out easier than others.
I pulled the boiler off. Terrible time putting it back together with all the pipes. There is a 5mm LED with a light pipe feeding up to the headlight.
http://www.hoseeker.net/assemblyexplosionbachmann/bachmannspectrum10wheeler460pg2.jpg
Rich
The resistance on mine was about 2.3k. Much too high.I found two resistors in parallel and in series with another resistor. Remove those and put in 1k, 1/4 watt resistor. They are marked with R. Remove the caps. Marked with C. Don't worry about the inductors. They look like green resistors or as I said before, hard wire. Rich
The resistance on mine was about 2.3k. Much too high.I found two resistors in parallel and in series with another resistor. Remove those and put in 1k, 1/4 watt resistor. They are marked with R. Remove the caps. Marked with C. Don't worry about the inductors. They look like green resistors or as I said before, hard wire.
Thank you gentlemen,
Tom,
I will follow your advise and protect the legs of the LED.
Rich,
The photos of the 4-6-0 clearly show which screws are involved, which is not clear in the exploded view.
I would probably follow your advice about hardwiring the decoder and get rid of the PC board. I have recently hard wired some decoders in diesel locomotives but I never thought that I could do it in a steamer. Maybe it's because I am intimidated with those steamers.
Hardwire is probably the best. Changing SMD resistors on the PC board is difficult.
I have seen many postings here and the Bachmann forums about dim lights in Bachmann locomotives.
richg1998 I have seen many postings here and the Bachmann forums about dim lights in Bachmann locomotives. Rich
As I could remember, the light was OK on DC. I think the light dimmed after I put a TSC DP2X-UK decoder. A simple plug in job. Is there any additional resistor in this decoder? I can't tell.
I never ran mine on DC. Look at the PC board. The resistors are clearly marked. The value is marked on the resistor. I used a magnifying glass to read them. Verified with my ohm meter.