Part Number:DRV11873
Hello!
I have a problem with the DRV11873 brushless motor driver. I connected a harddrive motor with 4 leads, com, 3 coils with 1.5 Ohms. The circuit is taken out of the datasheet with an LED on the RD (lock) pin. For PWM there is an AVR connected. The motor rotates ok. The problem is, it starts somwhat bad and unreliable. It wobbles a few times and mostly starts spinning then. Sometimes it doesnt make it and does not start to spin. Also there is no strength in starting. If I just put a tiny paper ontop of the motor it will not start up. I run a small ramp on the PWM and tryed with different frequencies in the range given in the datasheet (10 to 100 KHz).
The question is now if there is any trick on how to start the motor reliably. Can anyone suggest a frequency and duty cycle ramp that may work? The motor doesnt need to drive a lot of momentum, there is just a small weight attached to it. But it needs to be reliable.
Thankfull for any tips!
Best regards
