On Thursday, 8 November 2018 06:37:49 UTC, Phil Allison wrote:
tabby 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 ????

Live chassis TVs were very common in the 90s. Live chassis radios disappeared in the 60s.

FYI:

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

I was responding to your mention of 'hot chassis' not the OP's. What the OP mentioned is irrelevant.


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.

The UK government certainly disagrees with you. We have used isolation transformers for decades in bathrooms to reduce shock risk. Of course you're free to explain your pov.


NT