Err upgrade for scale turbine.

NO!  The resistor would be the hottest thing in the locomotive!

1A of power would be over the top for the smoke output of the R2LC, that will push you well over the operating temperature in only a few minutes.  Why not use the constant voltage board that's currently in the locomotive and just use a relay on the smoke output to switch track power to the constant voltage board.  No overload, and you already have the power source to drive the smoke units.

Wasn't sure. That's why I asked.

I like the relay idea. Do you have a recommendation on one?  Can the relay be used to replace the switch for the smoke units or does it need to switch the power to the constant voltage board?

Thanks for the help.

You want the smoke unit power to go through the switch and then through the relay NO and COM contacts.  The idea here is you can manually disable the smoke units with the switch, and you have command control of the smoke units with the relay. You use a diode and a 100uf 35V capacitor with the relay, that keeps any AC from reaching it, and also eliminates contact buzz from the half-wave power from the smoke output.  You will also need a .01uf capacitor directly across the smoke output to trigger the triac.

The relay that should do the job is this Songle SRD-12VDC-SL-C, eBay: 371662804965, 99 cents.

John - any chance you could give us a quick sketch of the wiring scheme you described in the previous post this topic?  I really enjoy learning from your posts!

Thanks John.  Is the cap wired across the connections (parallel) to trigger the relay and the diode is in series to trigger the relay correct?

The diode is in series, and the 100uf cap is directly across the relay coil.  The .01uf diode is directly across the smoke output to ground.  The output of the smoke control is positive, so the diode cathode faces the relay, and that's where the positive lead of the capacitor goes as well.

I was thinking of installing a cab light. Can I run 2 leds off the front light  terminal of the ac commander?

Sure, but remember to add the series resistor for current limiting.  Since the light outputs are negative half-wave in command mode, you'll need to connect the positive side of the LED's to frame ground, the negative side goes to the lighting output.  Somewhere in that circuit, you'll want a series resistor, try a 470 ohm, it should be good.

John, thanks for all the help. Finished the upgrade and it works great. Smoke control, led head light, fire box glow, and cab light. It's always nice to give new life to an old loc.

I love success stories, great that you got it all running.

The next upgrade I'll show you how to have two-level smoke, lower quantity when stopped and increasing to full smoke when moving.