It’s great to see you guys sharing the design progress on this ESC. I also saw that Makerbase recently merged a bunch of hardware configs with Vedder’s main branch, which is very helpful.
So did you also design the 75100 and 75200 aluminum pcb versions too? Are you an independent designer or working directly for Makerbase? Did the 75100&75200 alu designs get sold to Flipsky? Did they make the 75300 on their own? Sorry for all the questions, but I’ve been working on the hardware configs for the 75100 and 75200 controllers for a while and haven’t been able to piece together the whole design origin story.
I’m excited to see a 20s phase shunt ESC finally be commercially available thanks to the INA241. Also with 3 temp sensors and phase filters! The thermals on the 75100/75200 alu are really good, some of the best in fact, so I’d imagine this will be a great performer.
A few questions/suggestions:
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The DC-DC switch… so is this basically to shut off power to the STM32 and other chips so it can stay plugged into the battery without draining it? What’s the current draw with it on vs off at 20s? BTW for terminology you can use disable instead of disenable… or maybe just call it power on/power off if that’s it’s intended function? Or power on/sleep?
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The 75200 alu (and it appears this design as well) doesn’t have ceramic dc link caps on the power stage - do you plan to add those here or did you find them not to be necessary?
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How does the gate ringing look?
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On the 75200, the decoupling capacitors near the STM32 were placed a bit too far away and it was potentially messing with the motor’s voltage and current readings. An example (the yellow and black lines). Might be worth reviewing on this design too?
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How is the noise on the 5v and 3.3v rails?
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From a mechanical attachment standpoint, the 75200 had added epoxy to the standoffs between the power and logic PCBs which is a decent idea… but maybe consider the ability to screw the logic board down? There is a lot of vibration, and it can sometimes be tricky for the fab to consistently solder those standoffs to the power board especially with 5oz copper and an aluminum backing. I have seen these fail by lifting off the power board on other ESCs. Might need thermal reliefs built into the traces as well.
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+1 for posts instead of wires. 6AWG is very difficult to solder into the XT90 connector, and posts like the the MakerX G300 can make it easier to work with.
- There has been a lot of progress on the VESC Express which is an ESP32 based bluetooth module, compared to the NRF52 based ones most are using. Not necessarily recommending that, but maybe look into it to see if it makes sense over the NRF52 which isn’t really being updated anymore.