If you do that the driver won't be able to regulate at all. This means no ramping and no modes. I haven't tried it, though.
You still need to tweak the sense resistor stack value for it to work. You could try an R004 on top, it could work well or it may not. Add some heatsinking to the thing in such a case, as you'll be above the maximum power rating for single 1206 resistors (a couple stacked one doesn't changes this significantly). A good mound of thermal glue above sense resistor and MOSFET could help.
If the driver uses R010 for 6A this means sense voltage is Vsense = R × I = 10mΩ × 6A = 60mV. If you want to add 1.5A, you need Rextra = V / I = 60mV / 1.5A = 40mΩ or an R040 in parallel with the existing R010.
I have not measured how that driver behaves actually but if you really want to be sure to hit 7.5A, add some more conductance is my advice. I'd look for an R030, which would raise the maximum current to 8A theorerical (6A + 2A), albeit it would leave the actual figure in close proximity to 7.5A effective due to MOSFET heating, imho.
Yep, just gotta do the calculations and get the right resistor. Looks like an R010 on it, and max of 5A. Depends on how far you want to go, as to what you need:
6A total: Add an R050
7A total: Add an R025
7.5A total: Add an R020
Thank you guys!!
The only thing that was turning me away from this driver was the overaggressive thermal throttling!
Now a way to get a bit for regulated current out of it? SWEET
In what reviews I spotted of the SST40 based S21A, when you engage Turbo Mode, it almost immediately starts stepping down, pretty much negating anything useful of that mode.
I have to replace the driver in my nephew's S2+, torch predominantly used with the short tube, guess I won't mess with thermal throttling in that one. The other driver, though, is another story.
I did some electronics courses a very long time ago, so I’ve basically forgotten everything I ever learned…
