Crystalyte 35a controllers

[Mathurin]

i have posted before about how i am using the irfb4310 in these controllers as a general 100v replacement. they seem to be performing reliably and putting 8 of them in a 20a controller and modifying the shunt seems to make it a reliable 35a unit. i have not checked these in very hot weather, so it will be important to watch it when it gets hot and see if more heat sink is called for. the lower Rds-on would lead me to believe it will not be needed.

So one could get away with the 72v20A controller with better fets and such for 35A, saving .75Kg and a fair bit of space over a 35A model.

Nice!

 

[knoxie]

Yes

Half the fets as well, I have also been thinking along the same lines as well! they will run a little hotter though, the big ones do cool better.

Cheers

Knoxie

 

[fechter]

I've run my 3808 (75v rated) controller on a 60v pack with no problems. Right off the charger, the pack is around 65v. I don't think voltage spikes are the main cause of failure. The main capacitors are there to absorb most of the spikes.

When you run a higher voltage, since the input current has the same limit, the output current can be much higher under partial throttle.

Depending on the resistance of the phase wires, the peak current is apparently high enough to blow the stock FETs. Perhaps the people running 72v with no problems are using longer phase wires, which have enough resistance to limit the output current .

I'm glad to hear the 4310's work OK. Bob, did you ever look at the gate signals with an oscilloscope?