Originally Posted by Sephiroth

lol... yeah, I understand the bridge rectifier is for the AC off the secondary coil...

but what I am saying is that when the coil first becomes energized it induces current in the secondary at an equal voltage to the primary voltage. Then when the coil de-energizes, that is when we get the voltage spike going in the opposite direction to the originally induced current from the coil energizing.

So here is why I don't understand why we use the bridge. The energy being gathered by the secondary coil when the coil energizes is being taken directly from the current supplied from the battery.

and that current will be at an equal voltage to the primary voltage.

So unless the charging battery or capacitor is at a lower voltage than the primary battery there won't even be any current in the secondary coil and so the recitifier is useless. And if the charging bank's voltage is lower then the input voltage then it will just be feeding off power from the primary. The real charging power comes from the collapsing field which induces current/voltage in the opposite direction and so only one diode should be neccessary even with a trifilar coil set up like it is in the bifilar.

Or am I completely wrong?