When we were discussing green electron current (differential mode) in the last post, I mentioned that common mode (CM) currents (red electrons) are typically caused by unbalanced differential mode (DM) currents. It’s pretty easy to visualize that in an unbalanced differential transmission system, one of the traces is longer, has an extra via, needs a branch, the spacing … [Read more...]
Mom! Dad! Do Open & Short Circuits Really Exist?
I debated whether I should introduce radiated pickup by the DM loop area next and then dismissed it so that I could continue with radiated emission from common mode (CM) currents. These tend to be very mysterious because they are typically caused by unbalanced differential mode (DM) currents. Often these are caused by a few extra grounds floating around somewhere in … [Read more...]
Radiated Emission from Green Electron Current
Well . . . I’m back. I hadn’t planned on being out of print so long and it will take a few paragraphs to bring everyone up to date.A number of you learned at the IEEE EMC Symposium in Pittsburgh that my family and I were taking our little travel trailer on an extended camping trip immediately after the symposium. There were several National Parks that we have wanted … [Read more...]
What is Differential and Common Mode Current?
Answering the title question will be a hot topic at the IEEE 2012 EMC Symposium in Pittsburgh. Hopefully many of you will have the chance to attend it this year. There are always some really great technical papers presented at this show – some more practical than others. If you’re there look me up. I’ll be spending some time at the Interference Technology booth, #817.The … [Read more...]
