I’d love a momentary power switch, and maybe 1-2A 5v output for LEDs
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Yes yes yes, so much yes!
Just a question, does the 16S rating negatively impact the usage at lower voltages (12S)? For example, is the typically higher Rds ON of MOSFETs rated for higher voltages gonna be a problem to achieve greater phase currents? (or would we have to modify the thermal management to account for it?)
Just the removal of the DRV and the phase filters alone would more than justify the major version bump for me…keep up the great work!
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Nope. The mosfets I have in mind are low enough Rds(on) to achieve the 120A motor current I have in mind. And that’s a conservative estimate. The little FOCer v1 had higher Rds(on) mosfets and that could do up to 140A
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Cool I had wanted to ask about that too, do you know if it’s just due to generational improvements in fets or is it because you specified bigger/more expensive ones that are effectively just spreading the load over more gate cells?
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Neither. It’s mostly the improvement of my ability to tune gate driver circuitry to achieve good stability of the mosfet. This is why I could go up to 140A on the little FOCer but only 80A with the CFOC2 with both having TO-220 mosfets. There’s still the limitation of the package itself that is a hard limit. But now I’m able to reach those limits with my designs which makes thermal management a big factor in keeping things running nice.
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the 1 to 2A 5v output is doable I think.
I can try the momentary switch support but it will be experimental. There are circuits that basically convert a momentary signal to a latched signal and that’s what I’ll try.
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So CFOC3 it is. Guess I’ll make another thread for it after I’ve gotten further in the design.
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Not sure if you meant circuits as in building it discretely, but if you add a single cheap flipflop IC, and a jumper to configure the switch input as either its normal path or routed through the flipflop, I reckon that could do it.
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Yeah discretely is what I had in mind since discrete components are in better supply right now. I could do a flipflop IC or make a flipflop circuit out of NOR gates but the issue again is finding good stock of this stuff.
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Havn’t studied the design enough, did you implement the push to start circuitry?
Since you removed the DRV this might be bit harder to since its tied to the EN pin
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I haven’t done a huge amount of research but a quick check on digikey showed around 3,000 flipflop IC models in stock, the first one I checked had over 10,000 ready to ship. Is it very inconsistent with availability and they might not last, or am I missing something else?
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It’s about finding one on JLCPCB/LCSC and in a small package. Digikey is nice for me in making these for sale but not great for the DIYer using JLCPCB to do most of the assembly and sourcing.
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No I didn’t implement this. Yeah I’d have to adapt this to an enable with different logic since I’m not using the drv
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I’m mostly going through this for my own experience rather than backseat driving, feel free to disregard it. This looks like it fits the bill; 25,000+ in stock and SOT23,
Or this is even smaller
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Good job! I’ll read the datasheets this week and see if they’ll be good candidates.
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I was hoping for integration with the firmware’s momentary switch features.
Tho any momentary support would be better than a 2 position, I had my EUC shut off when it fell over once (it has an in/out latching switch), and I’m forever worried it might shut off if it hit a gnarly bump.
LED power will be awesome, even if its limited 1 amp, that’s 20x ws2811b, maybe a little less if there controlled by an esp32
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Firmware based shutdown isn’t true shutdown in my opinion. Everything but the STM is still fully powered on and sapping energy. I prefer implementing a true shutdown where the drain on the battery is less than 1mA when turned off.
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This is actually happening
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Switch guards might help too. Widely used in the heavy ass military comms equipment I used to haul around. Keeps the bumps from switching/damaging the switch. Would probably work for the button type latch switch too
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Greats news on cfoc 3 can’t wait for updates. Will the layout and bolt holes stay the same as V2 cfoc for easy upgrade?
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