I finished soldering Open-BLDC V0.1 boards and took some pictures while doing so.
After connecting it to the power everything seems to work properly and nothing is burning. That is really good news.
One little thing that is bothering me. The board draws 60mA, what is a value that I expected. The 5V linear regulator gets really warm. I am not sure if that will be a problem or not. But I did not find any other problems or screwups yet, even the big MOSFETs can be soldered using a simple soldering iron. It takes some time though, because the board and the MOSFETs are monstrous heatsinks.
More news coming up as soon as I start playing around with the software.
your openbldc project look like in a good state. But i think you can not get optimal controllability using allegromicro hall effect current sensors. According to dataheet sensitivity of ACS712 is a little poor. For example if a %10 load current changes this means rouglhy 200 mv of current change on output voltage. And this limit is ACS712 is sensitivity boundary.you can find sufficient information of ACS712 datasheet at page 6.
This current sensing scheme can not be used for sensitive position control aplications and rapid changed loads.
That is a serious consideretion. I have not tried to do vector control yet. I am still fighting with BEMF for now. But as it nears a usable state I hope to get to that soon. If this becomes a real problem I may switch to shunt based current sensing. I wanted to avoid that because I had bad experiances with that. Like for example burning shunts. Future will show. But thanks for this pointer.
Hello Esden,
big respect for the project, looks really good! I was wondering how you overcame the problems of the bemf not being well conditioned in v0.1? And is the lowpassing capacitor really necessary, since we’re sampling synchronously?