I recently aquired two brass locos. Both are in mint condition and have not been painted. My intention is to paint both engines but before I do that I would like to fit their headlights with bulbs. I will more than likely go with LED’s. The question is. What’s the easiest way to do this without adding unwanted detail such as heavy wires? I realize I will have to drill.[:0]
With incandescent bulbs, only one wire would be necessary because the brass locomotive shell could serve as one of the conductors since it is probably already used as one of the conductors to the motor. Trying to use an LED headlight would necessitate the use of two wires and some way, such as a small bridge rectifier, to maintain the proper polarity, assuming you’re going to use DC power and not DCC.
Fergie;
Piece of cake
You are going to have to find a volume of about 1/4" x 1/4" x 1/2" for electronics. Often you can remove the smoke box door on brass locomotives, and there may be space there - shortening the weight is one option.
Go with the LED. One way to do it is here:
http://mywebpages.comcast.net/mjmx/lights.htm
I would do it similarily except using a seperate bridge rectiifier, and LM317LZ (smaller than the TO-220 case). This can be used with DC or DCC. Use the smallest wire that you feel comfortable with, 38 guage is plenty big for the current load.
The two sources that I use for electronic parts are:
http://www.digikey.com/
and
http://www.allelectronics.com/
E-mail me if you want me to send you a circuit diagram.