Switching Incandescent Bulb to LED

[C.S.R.R. Manager]

Hi guys, I'm wanting to replace the incandescent bulb on the old DC powered 2-6-0 with an LED headlight, the sort that comes with current Bachmann kits.  The LED would be wired in parallel with the motor, so it's getting track voltage, which I'm pretty sure is too much.  Would I need to bridge the wires to the headlight with a resistor?  Can someone suggest the size of resistor to use?

Any help would be appreciated.  As you can tell, I know just enough to be dangerous.

Manager

[Tim]

C.S.S.R.

You need to put a 680 ohm resistor in series with the led.

If you want the led to light in both directions you will also
need to insert a bridge rectifier in the circuit.  With the ac
terminals to the motor.  You still need the resistor.

Tim Anders
Souderton, PA

[jpipkin]

Since you are not using DCC you might want to consider a 470 ohm resistor.  It will give you a slightly brighter light at lower voltages yet still handle full power.  I used a 5 mm golden white LED on a 2-6-0 with great success.  The after market LED is much brighter than the Bachmann LED's.  It is also less yellow but has no blue tint like white LED's.

Jim Pipkin