Not foc DT compensation. That reduces dt at low rpm in foc mode. I mean the deadtime number in the hw ifdefs. Transistor gate capacitance and gate resistance is an RC circuit. It has to charge up to 3.5V to start turning on, then it needs the miller charge, then it is on. If you use gate resistor that is 4x or 10x as large, it makes sense that it would take slightly longer to turn the transistors on. Its obviously not noticeable, so it is probably not a problem, but if it was my VESC i would flip my board over and take 5 min to look at the gate waveforms on the scope to double check.
The default is 60 timer counts (at 168mhz, this is about 357nS.)
The ntmfs5c628nl has a gate charge of 54nC, and an input capacitance pf 3.6nF. With 47 ohm gate resisfors this results in a rise/fall time of ~300nS. It cuts it close, but if there were problems with shoot-through, we wouldve encountered thermal problems during testing fairly quickly.
You definitely would have noticed a problem by now. Sorry to be a negative nancy today
No problem, I actually forgot about dead time insertion with respect to the gate resistors, thanks for bringing it up. Always good to indicate all possible problems with changes.
I need this also, but itās a bit daunting when I donāt even have a work bench. Can anyone provide this service?
well I dont have the equipment/ experience nor the time to make it worth while. Idk be creative contact people that knows their ways around electronics and supply them with the resistors and the vesc and a few beers. Or go to a computer repair store and se if they can do it after hours or something.
@boramiNYC I searched for all kinds of service providers in order to find someone capable of doing this repair down here in Miami. I havenāt gone to see him yet, nor do I know how much he will charge for this repair, but its a Computer Motherboard repair shop. You might be able to find someone in NY doing this type of work. Someone who āreally repairsā phones might be able to do it as well, but def not a shop that just replaces broken screens mostly.
@boramiNYC just an idea. Just look up Loius Rossmann(https://www.youtube.com/user/rossmanngroup) on youtube. He does board level repair. Maybe he can help you.
It took a couple of hours but I maneged to change the resistors and oh boy did it work! No more cut-offs!
Hey thats awesome to hear! glad we could help!
Where u ordered them? I guess 602 size is all thats needed and 1% tolerance, right?
Not sure I will order from Arrow, so should find alternative locally
I got them from a local shop here in Sweden. But I think as long the size, tolerance and of course the resistance is correct it should work. It took me a few tries to get the motor to spin correctly due to one or two resistors not soldered correctly. So no worries when it comes to burning the vesc
Actually I need to do 24 of them! I have 2 dual vescsā¦ Groanā¦
I talked to drv wizard himself and he seems willing to do them at his vesc repair price but offers no guarantee or warranty on this flipsky fix. Ive sent my focboxes and vescs to him many times and he returns them flawless. I am absolutely getting this done!!
Successfully!!! installed the 603 resistors for dual 4.20 took couple of hours and the freaking flipsky anti spark explode! ruined my discharge port and lucky not dangerous. Iām sticking x90 loop key from now on.
Any update from flipsky about the new resistor modification for 4.20 fvesc? Iām planning buy another one for my second eboard.
look more up in the thread. there is a statement from flipsky and what they going to do.
Flipsky are now shipping all their 4.20 based Vescās with the newer resistors. They just have not had time to update their website as they are in the middle of moving their entire factory. Have seen and gotten a few questions regarding it so I thought I might post it here.
So who is going to be the one to order one for science? Thank you to @Schtekarsten and @Gamer43 for going out of your way to figure out their mistake.