Rectifier Input Transformer Purpose

[ThePunisher]

This may be a very simple question to ask but I'll ask anyway. I would like to inquire as to what is the purpose of an input transformer on a 3 phase rectifier (battery charger)aside from stepping down the voltage? When is this not required with a 3 phase battery charger?

 

[ScottyUK]

If an isolation transformer is not provided then the DC positive and negative poles are essentially live at the potential of whichever phase has a diode or thyristor in conduction at any given instant. Most DC systems operate with either one pole grounded or as a fully floating system.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[itsmoked]

In a word: Safety.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[ThePunisher]

Thank you very much. Now is clear for me.

 

[waross]

There are rectifier schemes that don't use a transformer. Perhaps the most familiar is the automotive alternator where the AC output of the alternator is rectfied directly without the use of a transformer.

Bill
--------------------
"Why not the best?"
Jimmy Carter