On Thu, Sep 8, 2011 at 12:35 AM, David VanHorn wrote: > > Why is that? Due to inductive/electromagnetic effect? > > Light bulb resistance is non-linear with temperature. > > I'd think that a constant current sink into a transistor would be a > better way to go, you can water cool if needed, but 100W isn't that > bad even with just passive air cooling. > Wow, I completely missed that. And I'll probably never go above 15W anyway, so yeah, I could use maybe 4 power transistors in parallel and regulate eac= h individual one to sink an equal current to a total of whatever I want. I already have constant current source designed, so this shouldn't be too hard. Perfect, I'll just go this route. > A constant power load would be a little more interesting. > Wouldn't that be my constant current source with a voltage monitor at the terminals? Adjust current to get IV =3D whatever Wattage you want. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .