I have been reading some posts from several years ago concerning the modification of the above smoke unit when installing in a TMCC equipped loco. 20 ohms was mentioned as the safe limit to create more heat for the smoke unit. What wattage and what is a good source is my question.
Rod: Do you have any tips on how you wire-brush the coating off those resistors without nicking the resistor wire?
What I do is use the Dremel SS wire brush and go across the resistor parallel to the wires inside. That minimizes the tendency to break the wires. Also, I use a light touch to just knock the ceramic coating off.
The resistor should be a 2W or 3W wire-wound the correct physical size to fit without shorting to the sides of the bowl. I also take the square 5W wire-wound resistors and crack the ceramic off them in a vise, a perfect resistor for smoke lives inside.
Many thanks Gentlemen!
I have used 18 ohm in the 8057-200 successfully, running command. Smokes really well. I have also tried mth's 16 ohm resistor, but it is a bit much. Ideally you want about 10-12 watts to make good smoke IMO. This translates to about 0.6 amps additional load when the smoke unit is switched on.
The problem with going lower than 20-22 ohms is the dissipation in the smoke triac, I measured the triac temperature with 18 ohms at 18V track power, and it was around 90C, a bit higher than I want to see. The 20 ohm resistor topped out at around 75C, pretty warm, but well within reason.
FWIW, I get more than sufficient smoke with 20 ohms with TMCC, so that's my standard upgrade value.