Hello,
I always wondered if this was possible after reading about Chris Meyer's 9v backward compatibility for new plastic track. I haven't seen other posts about this; am I really the first to have tried it? I can't believe that.
Nothing fancy, just copper tape on the rails:
It's only a rudimentary test (having moved, I don't have a 9v train motor on hand right now), but it seems quite promising. Wide curves, anyone?