Varying the Voltage of a Flyer Transformer at Remote Locations

[lionelsoni]

That rheostat is certainly suitable, in fact, a bit of an overkill.  The Cenco price is $117.50:  http://www.cencophysics.com/air-cooled-laboratory-rheostat/p/IG0038227/

The behavior of Flyer trains is very similar to Lionel.  Both used universal motors.  The main difference is that Flyer locomotives draw a little less current, due to their smaller size.  With a transformer powering a universal motor, speed will vary with load.  Adding a rheostat will exaggerate that effect somewhat.

Tim asked whether he should keep one rail common between two regions powered by different transformers.  There is no good reason not to; and it lets you use an SPDT switch instead of DPDT.

I suggest that you switch transformers after the train has crossed into the local block, rather than before.  (And switch back before the train leaves the block.)  The toggle switch is easily fast enough that there will be no hesitation; and this avoids ever connecting the transformers together.

For enquiring minds:  An ideal series motor (like a universal motor) acts like a resistor whose resistance is proportional to speed and torque proportional to the square of current.  For a real motor, add a constant winding resistance to the speed-proportional resistance.

[Timboy]

Bob:  I never thought of it before, but the Gilbert factory issued a slide switch to manually reverse polarity once the loco is in a reverse loop.  It worked so fast that the loco didn't even hiccup.  So I think you are right.  A SPDT switch could be thrown fast enough.  I had to re-read your note to understand what you meant by "...connecting the transformers together".  I understand.  It isn't through the base post.  It's through the loco itself as the tender wheelsets bridge two transformers - when adjacent blocks are powered up by two different transformers.  So, a single insulated rail joint or air gap is sufficient - on the variable post rail of course.

I am relieved that I won't have to go to DCC again to do what I want to do.  Granted, DCC is awesome; but this is a retro-style Flyer RR I'm building and I so want to stay on point. 

Thanks!

Timboy