I totally agree. I’ve killed a controller by messing with the 5v pin. Best to only use the 3v(not for leds though).
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Having trouble powering my qs138 90h with V2.
It heats up at low speeds, don’t get great performance
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You can draw 500mA and be fine
Feel free to share more details via PM. Be prepared to tell about your thermal management and all relevant settings. Might be as simple as tweaking a few things.
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The main reason why I stay away nowadays is on other controllers I’ve broken them by accidentally shorting to ground. Would that kill your focer?
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The 5V supply has an over-current limit and will go into protection mode. It shouldn’t result in damage as long as the controller was otherwise idle. If it happens mid operation of a motor, then the logic side experiences a blackout and is subjected to a sudden stop in motor operation.
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Oh that’s very good to know. Thank you. I started out by using it to charge my phone. It was too low current for any newer phone. It also made my adc not work. I don’t recommend doing that 
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Alright guys! Here’s the Little FOCer finally all wrapped up in an enclosure! Check it out!
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Beautiful. Nice work on that case.
le giggle 
Whats the status on the controller? how many is out in the wild? any obvious setbacks?
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More than one of them haha.
And so far I am the only one dumb enough to accidentally leave off current limit mode then hit some drops, frying it then some sketchy SMD repair and get back rolling.
Oh wait lol I wired it backward on first setup too forgot to mention that. Quick DRV swap fix.
@shaman what blows up with reverse polarity on this Rev3?
hmm wait actually @kevingraehl melted his fets slightly or something on this one.
I don’t have an exact count that’s out there but there’s quite a few across several different applications.
The 250A rating isn’t something I recommend starting out with. Try building up to it from a more conservative limit. Very high kv motors (>300kV) tend to need more conservative limits where hub motors and lower kv motors are fine.
Thermal management is always key here. The stock heatsink is just a brick of aluminum. I recommend implementing some way of heat rejection in your system. Achieving that 250A requires excellent thermal management.
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The v3 units have reverse polarity protection for the control circuitry since certain people had a habit of somehow plugging in the v1 units in backwards. The large caps would be the ones to take damage depending on how long the reverse polarity condition lasts.
The people melting anything on the controllers tended to be the ones not using good thermal management or skipping straight to the max limits with high-kv motors.
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was more giggling at the “peek” phase current, than the actual value 
Good to hear you’re progressing making cool stuff! 
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Believe or not it can do 250A peak phase current in the right conditions. Again not something I would immediately try without first trying more conservative limits. For example, a tester recently tried 225A while building up to 250A but his system couldn’t handle that much torque
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Just wanted to post some pics and videos of my focer builds. Been working on a cool drift trike, awd go karts and a liquid-cooled pit bike. Check out the pics n shit. Little kart is 4 cheap focers, red pit bike is a little focer v3 everything else is using the little focer v1.
https://photos.app.goo.gl/94cFzyXaiFSfkram8
Thanks for making such a kick ass controller for a good price @shaman 
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Was that me? I sent you a message regarding some things that happened with a different revision of these, lmk when you’ve got the time to check it out!
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No your issue was different. It had to do with the kv of the motor you were using.
To be more specific, the HTD belt of the tester I was talking about couldn’t handle the torque of the motor when given 225A and the belt came off.
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Yep the controller has more to give my pit bike but the belt was slipping.
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Do you have a build thread or pics of your pitbike?
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