Andrew Mawson wrote:

415v to 240v transformer feeding your wall wart - three phase has 415v
phase to phase and 240 (ish) phase to neutral so you take any two
phases as the 415v input to your transformer. Such transformers widely
used to power lights and such like on industrial machine with no
neutral feed. RS components stock them.


Thanks Andrew, that prompted me to have a look and JMS transformers made me
one with a 415V primary and 240V secondary ( for a heating time switch)
plus a 18V secondary with rectifier and smoothing capacitor (to supply the
gps device) Wired it all in today and it seems to work, as things are a bit
cramped I will check how warm everything gets in the morning.

AJH