Paul & Sabrina's cheap DIY 144v motor controller

[Ken6881]

No, just when the throttle is pressed

[MPaulHolmes]

OK, then the pwm isn't making it from the microcontroller to the output of the driver. We just need to backtrack until we find where it's not making it. It's then probably just a bad solder joint or something. OK! Now, check the voltage across R16. One probe on one side of R16, and the other on the other side of R16, at zero throttle and at some nonzero throttle.

[Ken6881]

there is no voltage across r16 at any time ( i did check my voltmeter to ensure it was working)

[MPaulHolmes]

OK, so the mosfet driver is probably fine. The next culprit to check out is the HCPL-4504 optocoupler. Check opposite sides of R15 at zero and full throttle.

[Ken6881]

it is also zero at all times

for fun i went ahead and checked r14 and it is .88v at all times

[MPaulHolmes]

Try it with R12.

[Ken6881]

0v at zero throttle and 4.5v at full for R12

[mora]

Is your controller connected to a motor? If yes, how? (I mean which wire goes where).

[MPaulHolmes]

Well good! the PWM is working!! What's Pin 2, 6, 9, or 13 doing of the NAND (U5)? They should all be connected together, so I guess you could check that the resistance from one of those 4 pins to another is almost zero. I'd check ALL the solder joints connected in any way to U5, because I think that's where the problem is.

[Ken6881]

That was it, resoldered U5 pins and tested PH1 and PH2 to GR 1-10, got voltages. Then reconnected to pack, precharged, closed contactor. Controls motor! Thanks Paul!