Skip to main content

I have a MTH Imperial S2 Turbine (30-1308-1) that began life as a Protosound locomotive.  Many years ago I converted it to PS2.

Now the PS2 boards were lost to a short circuit and kits are not available, so I decided to upgrade it to TMCC using a Cruise Commander and RS Commander boards.

During the upgrade from PS to PS2, I cut the trace on the smoke unit (SS100).  Now that I am going to ERR, what do I need to do to the smoke unit?  With twin 18Ω resistors, the smoke unit is 9Ω.  There is nothing in the ERR documentation about the resistance of the smoke unit.

Any suggestions?

Original Post

Replies sorted oldest to newest

I take the Stackpole CB5JB20R0 which is a 5W 20 ohm resistor.  I put it diagonally in my vise long ways and slightly tighten.  The outer square ceramic shell cracks away and I end up with a perfectly formed smoke resistor.  Much faster than cleaning the ceramic powder off the other offerings.

After a few bench tests and measuring the temperature rise in the smoke triac, I've determined that 20 ohms is the lowest you can go and still be relatively safe with the power dissipation of the smoke triac at 18 volts on the track.  I've talked to people that have used one of the 16 ohm MTH resistors, but when I tested with that value at 18 volts, the smoke triac got close to 100C, too hot for me to be comfortable with it.  With the 20 ohm, the triac never gets past the mid 60's in my testing.  I can live with that.


Images (1)
  • mceclip0

My conversion is almost finished.  All the lights are LED's and the smoke heater works great with a single 20Ω resistor wired through the feature channel.

What I am left with is how to power the 5vdc smoke fan motor using the Cruise Commander and Sound Commander boards.  I do not see a 5vdc connection anywhere.  Is there anyway to connect it that can be controlled via TMCC?  It would be great if the fan ran slowly at idle then sped up when the locomotive started to move, like GRJ's Super Chuffer without the chuff (it's a turbine).  I could use an AC/DC buck converter and a latching relay to turn it off and on, but that seems like an awful lot of hardware for one dinky little motor.

Any ideas?

You can actually power your fan power off the smoke output as well, that way the smoke fan run with the smoke.  No relays in sight.

Truthfully, since the smoke motor only draws 30-40ma, you can do it with three components, a diode, 220uf 35V cap, and the LM7805T regulator.  40ma isn't worth wasting a switcher on.   I use the TO-220 regulator as it will run nice and cool with 40ma, the TO-92 low power one actually gets a little toasty with 40ma.

Add Reply

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
Link copied to your clipboard.