I’ve send a mail to jlcpcb about the issue, because even with mouse bites it is to be considered a single board. Also, open source is in their interest - they can only gain from that.
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My reference for doing this is again the MP2 design, where they have a triple parallel mosfet setup, and they use the same mosfets as I do. It’s certainly simple in terms of the schematics. The issue seems to be in the pcb layout and correct choice of mosfets.
BUT, if you want to move up the ladder of getting more and more amps through an esc, I think it is the way to go, as long as you remember individual gate resistors, which is what I forgot in the hush.
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In my current understanding, there are three parameters of consideration in the case of paralleled mosfets. Supposedly, with extra attention the negative influences can be counteracted effectively:
| Parameter | description | Effective solution |
|---|---|---|
| RDS(on) | gate on resistance | Tight pcb layout for equalized junction temperatures. Add lots of solder to junction. |
| QG | gate input charge | Smaller value resistors in parallel at the mosfet side, and one larger common gate resistor at the gate driver side. |
| VGS (threshold) | gate input threshold | The mosfet of lowest threshold will be first on last off, increasing its dissipated power → increased temperature → even lower threshold → BAD. Again tight pcb layout for reducing parasitic resistance and inductance. Lots of solder at junction. A single gate driver for driving all paralleled mosfets is recommended. |
In particular, variations in VGS (threshold) are important to keep as low as possible.
To this I should add that to keep junction temperatures at their lowest, attention should be payed to keeping switching losses at a minimum. This of course requires good gate drivers for fast switch on. Fast switching off is addressed by the added local PNP turn-off circuits (this can also be too fast → dv/dt stuff). I might have to reconsider my choice of gate drivers.
| Gate driver | current (src/drain) | datasheet | LCSC ref. | price | in stock |
|---|---|---|---|---|---|
| EG3112 | 1A/1.5A | EG3112 datasheet | C111908 | US$ 0.45 | 5182 |
| IRS21867S | 4A/4A | https://datasheet.lcsc.com/lcsc/1809291620_Infineon-Technologies-IRS21867STRPBF_C52290.pdf | C52290 | US$ 1.13 | 4685 |
| TF2190 | 4.5A/4.5A | https://datasheet.lcsc.com/lcsc/2207181730_TFSS-TF2190M-TAH_C2917161.pdf | C2917161 | US$ 1.47 | 5959 |
Above I have shown 3 potential gate drivers. Currently, I use the EG3112 due to its very low price. But it cannot source more than 1A, and therefore is not able to switch on as fast as the two other alternatives. Considering that the driver is now switching mosfets in parallel, I will change the design to use the “IRS21867S” instead. It has the same pin-layout, so I don’t really have to change anything except the BOM. I have used this driver in one of my previous designs, so I’m comfortable with it.
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Remember though that the faster you switch the greater the spiking/ringing in the circuit. Circuit layout is even more critical as things speed up.
There’s always a frakkin’ compromise. 
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Good luck!
I would like to add support for a power button, whatever that is.
Do you or anybody know the specifications for such a power button?
I can see that the vesc has an MCU input for “shutdown” - I guess you drive that input high, and you just want to be able to access that input via a pin on a jst connector or something, right?
But that only drives the MCU in sleep mode doesn’t it? The power supply is still active and uses power, and I guess this is how it’s supposed to be, or?
Sorry, but I use this thread a little bit like a blog of what I do, so sometimes I’m answering some of my own questions.
But, the power-switch on the vesc seems to be like a latched relay - you pulse it. Just need to figure out if there’s anything on the board I need to shut down together with the mcu - like CAN, or power to NRF, etc. - and eventually, how to do that. Need to take a look at the vesc source code.
And, yes, for the MCU to wake-up from sleep, you obviously cannot shut down the serial chain of power supplies to the board: V_in → 12V → 5V → 3.3V. Must be kept running.
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@jens_overby I really admire your work, you are creating the future! I just wanted to say this) I’m following you with great interest and my “onewheel” is waiting for the final of the project! 
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Oh thanks a lot.
Maybe you then can tell me how I can get a onewheel? Is there any DIY onewheel projects? On Ali you can buy hubmotor that look like those on a onewheel. Here are 3 examples:
But you need this PAD that senses your foot pressure right? And why is it that you need that? Couldn’t you just use IMU for sensing if the platform isn’t horizontal, and then accelerate if it’s tilting forward or decelerate if it’s tilting backwards?
Or maybe you only need the pad for sensing if there’s a person standing on the onewheel or not, so it doesn’t take-off by itself.
I’m missing something in my understanding of the “wheel” 
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Don’t buy those Ali motors. Try this:
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It does use the IMU for that. The footswitch controls whether the board is on or off. Otherwise, when you stepped off, it would shoot at top speed in one direction or another until it crashed.
Yes, exactly.
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there are many different diy projects
https://youtube.com/playlist?list=PLiYCRuOFm1MNj5a5LCCYhqoHpRu8Sc1Fx&si=LF5RwsauU4BC-S84
https://youtu.be/0shWuGG8B4I?feature=shared
You can see mine here in this thread. OneWheel uses highly complex algorithms to maintain a central position under various conditions. this is a very interesting topic.
https://forum.esk8.news/t/yet-another-hoverboard-to-onewheel-project/60979/32
https://forum.esk8.news/t/diy-onewheel-hoverboard/18862
https://github.com/EFeru/hoverboard-firmware-hack-FOC
https://t.me/joinchat/BHWO_RKu2LT5ZxEkvUB8uw
here’s everything I use
I’m wondering if it’s difficult to adapt the firmware created by this OneWheel community for FOCKING?
I think it’s a funwheel community. 100% absolutely not endorsed by Future Motion.
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Are you thinking this one could be ready for release?
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I would try separate those battery terminals abit more, Might just be the pictures but they look too close for comfort. They seem to be in the middle of the current carrying polygon tho, which is good.
Whats you’re isolation and creepage distance?
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I’m testing it at the moment. It needs a few pull down resistors.
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