Chuck, if the ZW-L is really able to put out 180 watts on a channel, the peak voltage shouldn't really be much of an issue. If it's putting out a higher peak voltage chopped waveform, it still shouldn't be exceeding an average power of more than 180 watts. If it is, then I would consider it a poor design for it's intended purpose.
Also, since I believe 18V is close to full throttle setting, the output waveform should actually be pretty close to a sine wave with only some minor truncation on the trailing side.
Nothing in this thread has convinced me that we don't have a possible electrical noise issue. I don't say that's a certainty, only that it's one possibility. It seems clear that the test locomotives are not pulling anywhere close to 180 watts, so the operation of the ZW-L is suspect with the AC motors at the very least.
