Electronic DC Load Design and Testing

I keep saying that I need to build a DC Load to test the Power Supply designs and after a few Switching regulators reviewd and still no DC Load I decided it was time to get one done So wanting to support atleast 30V and 5Amps with the ability to hook up my Agilent 33622A Waveform generator and use a standard 5V signal to apply noise and other control signals + an accurate measurement on the shunt I set about designing one. Of course loads of folks have done one on the internet so I was in good company but adding my own features would keep me on my toes for design. I also wanted it to be stable and possibly have active cooling which was not part of this test but I did find an old CPU heatsink with a fan attached that will become part of the final build So I used my Keithley PSU to provide the source for testing and threw a range of signals at it all with great sucess I also tested to see "How Low I could Go" and managed to get the DC Load happily sinking over an amp into a meager 250mV source voltage. I was happy so now I need to get it into a case. Anyway, I hope you enjoy the video, sorry its just over an hour but its all there, the design, the testing, the lot. Blog post on Element 14 is here: http://www.element14.com/community/gr...