Problem with my BEMF (ESC control motor)
Hello !
I'm making a ESC for my BLDC motor. I used a STM32 (to generate my PWM), 3 IR2101 mosfet drivers (https://www.infineon.com/dgdl/ir2101.pdf?fileId=5546d462533600a4015355c7a755166c) and 6 mosfets to control the differents phases of the motor.
Here is my schematic:
I generate my PWM and here is what i get (PHASE A, B and C):
The signals seem correct. When I plug my motor here the signal. We can see the BEMF before after each signal (I guess).
But when I check my BEMF there is a problem.
This doesn't look like a BEMF (too many spikes and not the right voltage) and I don't know why. I try to change the frequency of the PWM, change the duty cycle or the delay between each phase but nothing change (and sometime it's worse...). Do you have an idea why ?
My STM run at 8MHz.
PWM frequency : 900Hz with a duty cycle of 5%.
During this test my motor consumes 12V / 0.8 A.