wesnewell wrote:That's what I'm talking about. A 72V controller shouldn't get that hot at only 84V. Mine runs cool as a cucumber on 100V. And for The Mighty volt, 4410 fets are rated for 100V not 75V.
That's because it has 100V
rated FETS and should therefore be runnable at 100V
. Just like my Lyens controller.
A "72V" controller gets that hot at 84V because - as I ascertained from experiment - it is only suitable to be run at under 80V (at least this one from this batch).
Do you not understand that is NO SUCH THING as a "75V" or "100V" FET per se
? These are just nominal
ratings given based on their ability to run at these voltages while effectively dissipating heat. Quality of components varies. Some behave better than their rated values and others worse. If they perform well at higher voltages, someone stamps it with one little number, if they perform more poorly and get hot, they get stamped with another little number. But they are often exactly the same components, from exactly the same production process that SHOULD perform the same. That's the joy of statistical variation in quality: the whole thing is crap shoot.
You can "shoulda" til the cows come home, but at the end of the day you pay your money, you take your chances. Sometimes you end up with great stuff for near nothing, sometimes you pay big bucks and end up with shit. Get used to it.
And, again, "This is China!"