Create a instaspin motor control

Martin Marmsoler

Other Parts Discussed in Thread: INSTASPIN-BLDC, CONTROLSUITE, DRV8312

Hi,

I saw a video about instaspin BLDC on youtube in which was explained the instaspin method. But something I didn't understand:

The instaspin uses how the traditional method the back emf. Why this is less complicated than the traditional method?

From where I get the back emf signal? When I have the back emf signal and want to integrate it, it's difficult because I have to change the frequency of the low pass filter or is that wrong?

I hope somewhere understand me and can help me.

Best regards

Martin

over 9 years ago

0 ChrisClearman over 9 years ago

TI__Guru** 118000 points

traditional Bemf detection methods require establishing specific zero cross (+ to - or - to +) events of the voltage signal, timing these events, and using that time to calculate the next commutation event.

InstaSPIN-BLDC samples the Bemf voltage constantly, and uses the total amount of voltage as the signal of when to immediately commutate. The signal being looked at can be filtered appropriately and spurious voltages can be averaged in so the preciseness of the zero cross is not so important. You then are commutating immediately based on how much magnetic flux produced voltage has "passed" your stator sensor so you can get better dynamic performance during loading and acceleration.

Is it simpler? By design I'd say no. But from the user side, only needing to choose a voltage threshold for your specific motor makes it simpler to use. And it is much more robust.

By the way, if you are looking at InstaSPIN-BLDC on a Piccolo device I'd suggest just stepping up to InstaSPIN-FOC. It is significantly higher performance and actually much simper to get a tuned current and/or velocity system.