I never saw that happen with a constant voltage transformer (transducer).
Are you sure yours is based on transformer/choke and not an inverter?
However, how do you measure AC with a moving coil meter?
From: firstname.lastname@example.org [mailto:email@example.com] On
Behalf Of John G3UUT
Another caution, this time about constant voltage transformers. I had
one of these and tried to use it to stabilise the mains to a signal
generator to improve drift. It sort of worked but the main problem with
it was that it distorted the mains waveform quite badly, sufficiently so
that a normal moving coil meter read very inaccurately
Amps mailing list