On 11/22/2017 03:16 PM, Stu jaxon wrote:

here's the model Norstar ST-750.. it's on ebay for half price used. so more or less this just a surge protector.?


That unit appears to be intended for those situations where, say a 120
VAC appliance sold in the U.S. is to be used in another country like the
UK on 240 VAC (also assuming the U.S. appliance can cope with 50 Hz vs
60 Hz). Vice-versa for using a UK-marketed appliance in the U.S. Most
likely it's a single winding transformer with a tap(s), which makes it
an autotransformer (no input-to-output isolation). But it could also
have separate primary and secondary coils. No way to tell from a
picture or not having a schematic. Sincerely,

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J. B. Wood e-mail: