Lionmaster Big Boy headlight LED conversion

I believe you also need a diode to prevent reverse voltage getting to the LED so it doesn't burn out.  You also need a filter of some kind or else it'll mess with the DCS signal.  Search the forums for passenger car LED info as the basics will be the same, and there have been many long threads about LED conversions.

The choke is 22uH and is placed to filter between what you are wiring and the track voltage.

Actually, you don't need anything but a 680 ohm resistor and a diode for reverse voltage protection.  The headlight is driven from the R2LC headlight output and receives half-wave track power for command operation.  For conventional operation, the headlight is full-wave track power.  No choke needed as you aren't putting any capacitive load across the track power feed.

gunrunnerjohn posted:

Actually, you don't need anything but a 680 ohm resistor and a diode for reverse voltage protection.  The headlight is driven from the R2LC headlight output and receives half-wave track power for command operation.  For conventional operation, the headlight is full-wave track power.  No choke needed as you aren't putting any capacitive load across the track power feed.

John, does it matter on which leg of the LED the resistor and diode go on?  And thank you everyone for the quick help. 

It doesn't matter which leg the components go to, but it IS important how the diode and LED are oriented.  The headlight output of the R2LC is negative in respect to frame ground, so you have to have the cathode of the diode (banded end) pointing at the headlight output.  The negative lead of the LED also has to go to the headlight lead side.  The positive side of the LED goes to frame ground.