hi,
recently i have made a project involving cd-rom brushless motor. In order to project the motors contol driver i used a triphase inverter with bjts and a microcontroller to make the logics. Because of logistic problems of my applicaqtion, i didn't use hall sensors but i made the one i think it's called open loop actuation.
To avoid problems to the start-up of the motor, i set the rotor in a definited position before of becoming the actuation. It works fine and it's just quite performant for my application.
The problem is that i must write a paper about, and i can't justificate my way of proceding whitin the fact that he just do it. I read i little of documentation and it sims to be impossible to drive a bldc without sensor or the metod of back EMF. But i don't understand why this feedback is really needed : maybe for the speed control ( i don't made it but i can see that if i increment the frequency of switching of the driver it goes faster, and that is what i need) or maybe for a torque trimmerable to the change of loads (my load is alwais quite the same) or to avoid a torque with steps ?
Can u help me? someone kwnows how to find good documentation on bldc or driver systems?
Thanks a lot and sorry for my english.
bye
recently i have made a project involving cd-rom brushless motor. In order to project the motors contol driver i used a triphase inverter with bjts and a microcontroller to make the logics. Because of logistic problems of my applicaqtion, i didn't use hall sensors but i made the one i think it's called open loop actuation.
To avoid problems to the start-up of the motor, i set the rotor in a definited position before of becoming the actuation. It works fine and it's just quite performant for my application.
The problem is that i must write a paper about, and i can't justificate my way of proceding whitin the fact that he just do it. I read i little of documentation and it sims to be impossible to drive a bldc without sensor or the metod of back EMF. But i don't understand why this feedback is really needed : maybe for the speed control ( i don't made it but i can see that if i increment the frequency of switching of the driver it goes faster, and that is what i need) or maybe for a torque trimmerable to the change of loads (my load is alwais quite the same) or to avoid a torque with steps ?
Can u help me? someone kwnows how to find good documentation on bldc or driver systems?
Thanks a lot and sorry for my english.
bye