Moving out to Singapore, I’ve become nearly disabled. No solder, no board, no multimeter, etc. Actually, my employer provides me with the tools, but I’m kinda hesitated to use it for my own personal use. I guess I have to buy it for my own later.
Anyway, since I’ve got nothing to do this Sunday, I’ve come up with quizzes, just to test my electronic insanity. What is the efficiency of these ugly linear PSUs ?
Simple Zener Rectifier
I’d say its efficiency is 17.59%..Here’s another one:
Current Feedback Linear Rectifier
My insanity said that it’s efficiency is 17.64%.
Is there anyone who has different answer than me ? 
