wrote:

Phil Allison wrote:




Isolation transformer are used a lot in servicing certain type of
electronic equipment (e.g. tube TVs, amplifier, radio transmitters,


** But only those examples where the items have no AC supply isolation
transformers - IOW they are *HOT CHASSIS* designs. All of them very old
and very obsolete.

Well, they were standard & widespread in the 1990s.



** Live chassis tube TVs and radios " standard & widespread " in the 1990s ????

FYI:

The OP did NIT even mention "live chassis" so his post was wrong and so is yours.



Contemporary use of 1:1 isolation transformers would be for
servicing devices like SMPSs.


It removes the direct path to ground of the electrical power,
significantly reducing the chance of death.

** That is wrong.

Using an isolation transformer allows one to connect the common
rail ( or any other point) of an off-line SMPS to safety ground.
After which you can use a scope in the normal way to investigate
various waveforms, maybe small ones like MOSFET drive signals.


One can, but they are also used to reduce shock risk.


** Biggest safety myth out.

Using an isolation transformer unnecessarily INCREASES electric shock risk.



..... Phil