supply to tranformer - what if supply is applied to passive

[among]

supply to tranformer

hi ,
im using a passive transformer in my application,
the suggesting circuit says that the 3.3v supply is connected to center tapping point.
what happened when supply is applied to passive tranformer.
Regards
among

 

[biff44]

Re: supply to tranformer

I have done that from time to time. It depends on how the transformer is being set up, and how the internal windings are made. RF transformers sometimes are not wound at all like you might think they are wound.

So, the first thing to check is how the transformer is wound. You want to make sure that putting a DC voltage on the center tap does not short circuit that voltage to DC ground!

Usually the center tap of an RF transformer is a virtual ground. If so, you can just connect a capacitor to ground at the center tap, and feed the DC voltage at that point.

I would not put too much voltage there, as these things are wound with very thin--poorly insulated wire that is twisted together into pairs and wound tightly onto ferrite rings with sharp edges.