What voltage are you using?
Are the mosfet tabs touching perhaps between phases?
I’m using 20s so 83ishV. Are the mosfet tabs not meant to touch? I thought they were grounded. That would definitely explain it.
The “upper” 6 mosfet tabs are on same potential(Vin), but the bottom six go to the phases. Out there, only each pairs tabs are on the same potential. I grinded down a litle from mosfet tabs to ensure there is no short betwen different pairs.
It is possible to use one switch for two boards?
Just ordered 10 boards for 77.34$ from jlcpcb including shipping but without extended components. I will have to order from lcsc either way.
Found some good prices for mosfet (0.30$), can chips(0.27$) and stm(2.28$) on aliexpress.
Anybody tried this mosfet driver ?
https://www.lcsc.com/product-detail/C20623204.html
It seems to be the same as the IRS21867STRPBF just for half the price.
You can do that with a simple relay for the power module buttons. Or a anti spark smart switch between controllers and battery and have the power module on always on
For the slower of us here, does that mean bare boards without even the surface mount components, or this was for 10 boards with the basic surface mount components installed?
Only basic surface mount components.
Im about to order the rest of the parts from lcsc.
Still not sure about the IRS21867STR(UMW) mosfet driver. I think i will find out.
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I dont want to use relay, and anti spark switch. Now i am turning off the bms completly, but when i charge its turns on the controllers also. I want to keep the key for the bms and use push button to turn on/off the controllers.
Then a double pole switch will do what you want
“Just use a loopkey” is usually the answer
Yeah the FETs should never touch, otherwise you have a big short. I always have isolation in between. (Heatpads which are unconductive) With 20s you can run really big motors!
yeah the boards work great, i use them all the time!
Thanks for the advice! I put epoxy between the tabs of my new board and it survived low current testing (20A) but when I loaded 100A settings in VESC-Tool the motor jumped and it shorted 2 phases from VBat to Gnd. Is it possible that programming settings in VESC-Tool caused uncontrolled signals from the mcu? I can’t think what else would have caused this.
Check you motor that should not happen. I already pulled more than 100Amps no problem are you using 6 or 12 FETs?
I use the same motor with another controller no problems. Perhaps I’m getting shorts between the shunt and FET legs? How do you avoid shorting them when you assemble the boards? I checked with a multimeter and they weren’t connected but there’s less than 1mm space.
I’m using 12 FETs btw
mhh with how are you cooling the fets?
the backside of the FETs should not be connected at all, if the are you have a complete short