I checked the PC boards for a 4-6-0 and 4-4-0 locomotives since there has been questions in the past.
The 4-6-0 PC board the decoder is plugged into has 1,770 ohms resistance in series with the plus lead, blue wire, for the LED. There is a diode in the minus lead, white wire, that drops the voltage by .7 volts. Good reason for dim lights when plugging a decoder into the PC board. If you hard wire a decoder, a 1,000 ohm resistor is sufficient. I have done that with a Spectrum 4-4-0 and a Spectrum 4-6-0.
The Spectrum 4-4-0 PC board has 1,424 ohms in series with the blue lead and a diode in series with the white lead.
I suspect the PC board for the 2-8-0 must be about the sames as the 4-6-0.
Rich
Rich
Thanks for the information, I plan to replace the lights on all my Connies with LEDs.
Now if I could only find the PC board and nomenclature picture Jim posted on his site. :D I switched computers and lost a bunch of his links.
Is this what you are looking for? I have never seen the 2-8-0 PC board up close so it may be different.
It is fairly easy to check with a ohm meter. Ok, maybe it is easy for me as I have been doing electronics since the 1950s.
http://members.shaw.ca/sask.rail/dcc/2-8-0/index.html
Rich
Thanks for the link. I'll try not to lose it again.
I have no problem with measuring the resistors, as I have also been in electronics for about 50 years, the problem is identifying where the parts are on the board. I can trace them out, but I hoped to see the board parts named.
In the good old "spaghetti" days, parts were easy to trace. However there aren't many parts on the board so shouldn't be too difficult.
It would be nice to have a schematic, like the old Howard Sams volumes. Unfortunately the factory considers the schematics "top secret".
Pull the PC board. Fairly easy to draw out the schematic. I have done it. Ok, I have to use an Optivisor.
Rich
I have a 5 diopter OptiVisor, but I need to get a stronger lens. It's heck to get old. >:(