power supply / transformer with more than one voltage out

Hi All; How does a transformer know what output voltage to supply when the output states 3.0 to 13.8v dc? There is no twist knob to select. I think its from an ethernet hdmi extender.

by gav22
September 17, 2022

It is generally linked to the number of turns before using a tap on the coil. If the coil has, say, 100 turns, then we can weld a T tap on the wire at 25, 50, and 100 turns to get the proportion of 25%, 50% and 100% of the full maximum voltage. The manual selector is then a switch about which tap (or which two taps) have to be used.

by vanderghast
September 20, 2022
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