Re: OPEN SOURCE: New Boost Drive, 2.4A capable from one cell, tested and working
I'm doing a digikey order this week, so I can test out some other inductors with the driver
Let me know which ones you have in mind (already added the 587-2956-1-ND to cart) and I'll test it out.
It would be worth testing the following inductors on the 850mA V14:
587-2956-1-ND
(which you've already added)
and
ASPI-6045S-470M-TCT-ND
What would also be hugely valuable would be if you could take the V15 and swap the RSET to lower its current to 850mA. V15 already used a higher inductance inductor, so testing it at 850mA and 6.5V (or something close to that) will give us useful information. If it scopes well, then we could consider not forking the driver at all (though we'd want to have a discussion in the thread about whether 2 forks of a small driver are preferable to 1 universal driver that needed to be larger - but we'll cross that bridge if we come to it).
One challenge is that I can't remember the scaling resistances I used, so I can't tell you exactly what RSET to purchase. Any chance you could measure the resistance on this?
I'm thinking it's around 500 ohms. I may have paralleled a couple resistors vertically. I can't remember. If you can test that resistance, I can find a part number for a set resistor that will switch this driver to 850mA.
EDIT: There was a question earlier about whether a zip file is out for the driver V14. In short, no, not yet. I know it's really tempting to want to use this driver since it's now scoping really cleanly for 445s, but there is some housekeeping / general tidy-up required. V14 had a few awkward component placements that, while not a show stopper, were annoying, and should be fixed. There was also a problem with the wire-holes not really being convenient. It also wasn't tailored to the exact dimensions of the inductor (because we were testing a couple different ones), so it's worth getting that right, now that we know what components we're landing on. Finally, in all likelihood, we should make it adjustable. So while it's exciting that we're at or near the end of the road here, there still a little bit more revision required to get this perfect. ARG's testing (above) may give us some ideas too.