Why no smoke in Legacy using conventional mode but smoke with DCS

in most MTH smoke units that I have seen there is two resistors which help MTH products produce more smoke at lower voltage.

If two resistors is all its takes then how idiotic of Lionel not to use that design.

I don't know about the Lionel engines and smoke output but it might be a design feature so that you will buy the new Lionel command control system to use the smoke feature. If so there is some electronic device in the Lionel engine that will sense whether you are using the Legacy control or not.

Lee Fritz

Try Using DCS to turn on you smoke unit and leave it on at desired smoke level. Then shut off the power. Then Try it in conventional mode.  

Art, don't have DCS or Legacy - just run trains with a Z1000. If you are saying that a smoke level set with DCS won't be maintained running in conventional then so be it. At least you can get a MTH loco with Proto 3 to consistently smoke in conventional mode which is more than can be said for Lionel Legacy locomotive.

So in summary, is it a given conclusion that legacy smoke will be anemic in conventional mode, when voltage is in the 12-15 volt range?

Try using a Lionel transformer if you can. I think the problem has to do with MTH pure sign wave vs Lionel chopped sign wave. I may have this backwards. I remember seeing a Lionel video about this subject.

Rod Miller

Hmmm, since the last time I ran the legacy locos in the dark (when I love to see the smoke), I switched from z1000s to a z4000. Seems smoke output is down more than it was before. You must be thinking of the famous Mike Regan video, I need to watch again. 

ns1001 posted:

If two resistors is all its takes then how idiotic of Lionel not to use that design.

Can you say patent?

Some Lionel engines need a transformer with a chopped sine wave to smoke good in conventional.  I have worked on a few Legacy Flyer engines with that same issue.  Rod is correct.  

Ok, so it sounds like I hurt my situation when I switched transformers since the z-1000s have a chopped sine and the z-4000 is a pure sine wave if I remember all the past posts correctly. It is a bit puzzling to me how MTH's  parallel resistors do better since the wattage is the same at a given voltage.  Here are my simple calculations. 

1) Assume lionel applies 10 volts to an 8 ohm heating resistor. P=VI=10*1.25 amps= 12.5 watts.  2) If I replace the 8 ohm with parallel 16 ohm resistors (assuming that was possible), then we have half the current in each leg and the power is 2*10volts*0.625amps = 12.5 watts.  Same as before. 

Does the resistance change on these heaters with higher voltage? Or does the wider dispersion of heat with two resistors do the trick?  I defer to the experts on this one.