You are here:

Electrical Engineering/Question on kickback voltage on coil


In this buck regulator circuit:
When current to primary coil is cutoff, kickback will develop on primary coil with polarity (+) at bottom. So direction of D1 is correct for this kickback voltage.
But on the secondary side, when current that was coming from the dot was cutoff, kickback would develop with polarity (+) on top (??)(to maintain the original direction of current). If that is the case D2 would be no help to absorb the kickback. Is there something I miss in this observation ?
Thank you!

D2 charges up the output cap whilst conducting.  D3 keeps the output cap from discharging whilst D2 is non-conducting and conducts forward as well to keep the charge at the output cap.

A full explanation of the buck converter is found at:

Hope this helps.  

Electrical Engineering

All Answers

Answers by Expert:

Ask Experts




All technical areas of Electronics Engineering.


BSEE, MBA, Design, R&D, University Research.
Senior Life Member of IEEE. Life Fellow of AES.

IEEE, Consumer Electronics Society, Audio Engineering Society.
Broad teaching experience; work experience mostly in consumer electronics and conversion from analog to digital technologies. Pioneer in digital audio at all levels.

BSEE (Equiv) BYU BSEE University of North Dakota MSBA (MBA) Illinois State University Graduate Studies in Computer Science - Bradley University Graduate Studies - Ohio University Graduate Studies - University of Missouri Kansas City DeVry Tech - Electronics

©2016 All rights reserved.