Thread: Variac question
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Phil Allison[_3_] Phil Allison[_3_] is offline
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Default Variac question

three_jeeps wrote:



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


** 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.

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.



..... Phil