quote:
Originally posted by rdigilio:
Steitzeit,
you are absolutly correct, but when I wanted to test my HV locos, I already had 2 Lionel Z transformers laying around, I didn't have a 220- 110 stepdown. Also for most people wiring one in reverse (i.e. swaping primary for secondary) could be confusing.
Another choice would be to use the same 220 step down wired to the 120 mains to get approx. 60 volts, then all that is needed is a suitable speed control.
Roland
I. I think it would be preferable for the step-down [ as an -up ] xformer to be wired on the output side of a regular transformer for a couple of reasons:
1) I think it is unwise to recommend that anything on the 'higher voltage' AC mains side be tinkered with; I would always assume that plugging into a wall outlet is the safer case -- especially if "most people" would find wiring the step down > up confusing.
2) One already has the safety device(s) [ circuit breaker, etc ] built into the train transformer, eg, between the 120 and the step up. When testing your work you can also do it at controlled low voltage, eg crack the throttle to 5 v and see if you get 10 at the track.
II. I'm a little rusty on "why" but I believe it's important when using the "two train transformers in series" approach that both be electrically identical, so that just using 'any two transformers might not be a good idea. I think many, if not most, readers have difficulty with phasing, which would be important here.
You give the impression you know what you're doing, of course.
Best, SZ