Does this look right? I made a basic can bus splitter (just jumper wires) and this is my plan
I am not 100% on if i need to tie all the 5v and gnd connections from one of the solos to power the xlite or if the xlite provides 5v. I don’t want to put two 5v sources together through ignorance
is can bus termination a problem for us when there’s more than two devices? i thought our devices had termination resistors built in.
Iirc total resistance of the can should be 60ohm- so whatever gets me there in the end. If two devices (the solos) have 120ohm termination resistors i am set. If the megan also has a 120 ohm resistor then thinks need tinkering. The ennoid xlite afaik doesn’t have a terminal resistor.
Megan has a CAN terminal resistor but it’s disabled by default. If needed it can be enabled by creating a solder bridge here:
I’m not sure 5V on the Ennoid needs to be (should be) connected. Doesn’t it get powered from the battery pack directly? And then GND probably doesn’t need to be connected either.
Other than that it looks good.
Don’t quote me but I believe it’s not strictly necessary to have exactly two terminal resistors. It will still work with 1 or 3 as well, though it’s not ideal.
XLITE-V3 do not have CAN bus termination resistors.
XLITE-V3 needs the 5V & CANGND to operate.
You mean “to operate in general” or “to communicate over CAN”? Because the former would seem weird. I guess it should still operate when charger is connected even if it doesn’t get 5V from ESC (or other device). Right?
It should wake up when it receives the 5v so that it can communicate to the vesc and megan but otherwise would enter sleep state? (assuming nothing else is causing it to be in the on state like charging/balancing)
I agree that was confusing…I try once more:
*XLITE-V3 needs 5V & CANGND for the CAN bus to operate
It’s been a while since I posted some news about my latest VESC. Many asked me questions, so I will give some info here.
I’m now up to version MK5 and will probably keep updating/improving/testing the whole thing before going into continuous production
Here are some details and some pictures:
I have a stable 100V version running/being tested for more than 2-3 month with very good results and a 150V version coming-in next week. Both support momentary switch which is a new feature in it’s category. Before that, I went through 3 hardware iteration before getting the push button/auto-shutdown+firmware to work flawlessly. The 100V version also has phase shunt sensor which allows a more efficient and smoother operation than usual low side shunt. Also a first AFAIK. it uses a 6 layers 2 oz fr4-cu pcb with blind vias when needed. It is simply the most complex PCB I have ever made so far
The aluminum case is actually the biggest challenge on my side. I had to go through many iterations and still doing many changes to make it perfect. Cooling is a big deal when it comes to high power and the actual case is very good at it. It is also possible to get the whole VESC watertight when using julet connector to interface with external devices which is very nice.
The 100V uses 1.2mOhm-100V rated mosfets and the 150V version uses 3mOhm-150V rated mosfets. (Using TOLL mosfets)
That mean that the 150V version will not be able to carry as much current as the 100V version on paper, which was to be expected, but both will be limited by the XT60 connector anyway.
Here are the things I’m still working on before going into main production:
I think that sums up well the status of my latest VESC.
I’m not planning to sell many of them for now, but I will slowly ramp up. The fungineer VESC is a serious competitor in the 100V VESC category. UBOX is dirt cheap, good design, but less capable in pure power terms. The FOcer was first to market, it is apparently reliable if handled properly and is also well established even though I’m not a big fan of the overall design. FOCer is way overated and UBOX underated IMO.
I think there is space for everyone on the market. My VESC brings some innovations, with a smaller form factor, nice aluminum case. Will it outperform the Fungineer VESC? I don’t know, but I think it will only depends on the cooling factor. The dual side cooling is quite hard to beat IMO.
24s fine for the 100v version or too high?
With regen brakes.
100V version is 20S max.
The 150V version will likely outperform the Tronic in current capability anyway. I know that some people are planning to use the tronic with 24S, but regen is apparently limited. I don’t know which exact mosfet they use but even the lowest RDson 125V rated mosfet on the market I can find have 2.9mOhm. 120V is the minimum required for 24S+regen, which is similar to the 3mohm 150V I’m using.
Aren’t toll mosfets made for primarily botom side cooling? but you use fr4 which is not as good as ims for cooling?
Yes, I agree, naked (no aluminum case) mk5 would be quite bad at cooling compared to your Fungineer VESC that use aluminum PCB.
Having a precisely machined aluminum box around the mosfets and PCB free space areas makes the mk5 quite good at removing heat. Also, phase shunt makes it a bit more efficient. Thermal potting is also an option with the actual aluminum case.
You can say, well lets design a similar case around the fungineer VESC. Then it would likely beat the mk5, but would also be a bit bigger. My end goal was to have something small, sealed and powerful enough for most use case. Going aluminum PCB with a second PCB for the logic side would make the whole thing a bit thicker and more tricky to assemble together/package. Ease of manufacturing (outside for the aluminum case) is why I kept the more traditionnal single board approach.
How phase shunt makes it a bit more efficient? Phase shunts are good for HFI and to measure current in any time. but this can not affect efficiency?
I will not comment this as I do not have experience with top side cooling of TOLL mosfets. If I remember correctly I read somewhere that bottom side cooling is 4* better in heat transfer as top side cooling.
They are designed to be cooled from the bottom.
But TOLL packages are primarily designed for Cu-IMS or FR-4, not Al-IMS (aluminum PCB’s). The CTE’s for the PCB and the FET package are quite different when using Al-IMS and that causes strain when thermally cycling a TOLL package FET. This can easily lead to failure of the component.
TOLG is a much better choice IMO for Al-IMS when thermal cycling is involved as the gull wings were designed to allow some flex. Not sure about how TOLT fits into all of this.
IMO, Cu-FR4 is a better choice when using TOLL.
As always, we design based on the strengths and weaknesses of each component (which includes the PCB) and how they interact along with considerations for SWAP-C (which can greatly impact our decisions).
I don’t want to jump into this. It is very technical, in some case you are right, very little to no gain, but in some area there are some real advantages of having phase instead of low side shunt. So much gain with phase sensing that most high power/high voltage controllers ditches the shunt sensor for the generally more bulky and less precise hall sensors due to the lack of any available shunt amplifier able to withstand the higher common mode voltage required for phase sensing.
I also havent mentionned the “risk” element associated of going with aluminum PCB. Indeed TOLG and TOLT seems to be better options when it comes to aluminum PCB and expecting long term reliability, but is also unique to infineon, subject to shortage and expensive.
Also, you can’t really cool on both sides when stacking PCBs together like the fungi vesc or ubox.
Very interesting. I look forward to trying those out.
