kZs0lt wrote:I'm experiencing cutouts as well with my 6Fet and 12Fet controllers fitted with 4110 FETs. I'm using 9C 9x7 motor.
The 6FET controller works fine with 20A battery, but set to 40A battery/100A Phase it cuts out.
The 12 FET controller I have set to 57A battery (max in Parameter designer) on the 9FET setting and it also cuts out with max throttle from a dead stop.
The shunts are about 5mOhm on the 6 FET, and about 2.5mOhm on the 12 FET. What are the shunt resistances stock on the 6 and 12 FETs?
Could someone summarize all the info gained in this cut-out problem?
2. What is the cause of the cut-out?
-Too high battery or too high phase current?
-Or the voltage on the shunt is too high?
-Could be caused by the QF1 transistor activating?
2. What are the solutions to fix the cut-out problems?
- program the board with a higher FET number -> In my opinion this alone should not make any difference, as it will cut out at the same power level
- lower the shunt resistance -> maybe this could help?
- remove QF1? -> some reported controller failure for this
- alter QF1 circuit(resistor across c20, etc) - someone reported that the cut-out was clearly not caused by this as it was experiencing it even with QF1 removed
If it is the problem that was resolved, this was due to the time constant circuit ( QF1 and c20 ) on the hard cutoff of the controller ( a extra safety feature built in to the controller ) basically the battery current needs to reduce at a rate that the controller is happy with. Removing QF1 Is not such a good idea as this will disable the feature all together, The resistor across c20 increases the time constant of the circuit and may still cut out at even higher extreems ( this works but can be a bit of a pain to fit the resistor), so the controller fets will still have some sort of protection. Re-programming with a higher fet count works because the timed window on the pin that the RC circuit goes to is increased for the more powerfull controllers but you will also have to adjust the shunt value (lower) to the same value in the bigger controller i.e a standard 6fet will need 2 shunts instead of 1 if programming as a 12fet.