Reply to "Increased American Models locomotive speed"

It's a lot to swallow at once, and it took me a few months to learn what I needed. This is what worked for me. From left to right on the diagram:

• a 22 milli-henry choke for about $0.44 each. This is an inexpensive option that makes the car more compatible with MTH's DCS system and more attractive if you decide to use DCS or to sell to the car to a DCS user later on. 

• a bridge rectifier to allow the passenger car to run on AC as well as DC. It is necessary to keep the LEDs illuminated when you change DC polarity to reverse an engine. (Without the rectifier, the lights would go out when you back up because reversing changes the positive DC track wheels to negative DC and the negative wheels to positive. The rectifier keeps the output current the same polarity even if the input changes. ) Rectifiers cost about $0.44 each.
• a 1000 micro-farad capacitor capable handling 35 volts (far more voltage than the track will ever see)
• the buck-boost converter in my example or a similar converter
• the LED strip in my example. The resistors and other components for the LEDs are already in the strip. It's just a matter of connecting the positive wire from the buck-boost to the the + solder point on the strip and the negative wire to the - solder point.

There is no need for a regulator with this setup. The choke filters the current. The rectifier keeps the same DC polarity to reach the LED strip whether the track has AC or DC current on it and if the DC polarity changes to reverse the locomotive. The capacitor stores a bit of energy to reduce flicker. Everything else is already built into the LED strip.

choke:

rectifier:

capacitor: