Quote:
Originally Posted by julie_m
Surely an electric toothbrush is an intermittent load?
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The toothbrush itself is only used intermittently, but they're generally designed to be left on charge continually (with coupling between the charger and the toothbrush itself being inductive).
The transformers in electric shaver units are generally designed to saturate easily, as a safety-feature: this provides a current-limit and a rapid drop of voltage once the current-draw reaches the design 'turnover' value.
[I once thought I could use one of these transformers - rectifying/smoothing its 115V output - as the HT supply for a piece of battery-valve equipment. Having felt how hot it got even with only 1/2 a Watt or so being drawn from the secondary, I soon changed my design plans]