When I'm doing an upgrade, I frequently come across some pretty ugly smoke PCB's. Previously, I had created a replacement PCB for the standard rectangular smoke unit, detailed in this thread: DIY Rectangular Smoke Unit Replacement PCB. However, the Smart Smoke Unit has a different diecast 2-piece case, so that PCB didn't work for a direct replacement. In the last two months, I've run across three of these smoke units where the PCB was toast, so I had to replace them. Given the spotty availability of the older TMCC stuff, I figure it's only a matter of time before I can't get these PCB's anymore.
In a preemptive strike, I simply am creating a replacement for upgrades. I dispensed with the screw terminals for attaching the smoke resistor, never did like those as they come loose, develop high resistance, and that destroys the pads they attach to, thus killing the PCB! Even if they don't kill the PCB, the smoke performance goes down hill when they come loose and necessitates opening up the locomotive to tighten them. The screws are also a bit of a PITA to deal with when replacing the smoke resistor. Finally, when I'm installing the Super-Chuffer, I don't need all the extra stuff on the smart smoke PCB, the Super-Chuffer does all those functions and more. I also wired the fan and heater connections to one connector making the removal/replacement of the smoke unit a little cleaner and easier.
I retained a simple power supply circuit for the fan to allow this to be used for diesel applications. To use the power supply for diesel fan, jumper J3 is installed to supply a power ground. For steam, I simply leave the power supply components off as the Super-Chuffer provides smoke fan power. The board is designed to mate to the 2-piece diecast smoke fluid reservoir and fan chamber.
