Hey guys! Today’s post will be a relatively short post compared to the last post, but I just wanted to update you guys on my project. Well, the first thing I want to mention is that I finally tested the circuit with the new Arduino, and it works perfectly! No short circuits, and the motor rotates properly. I included a picture of the schematic in the figure below. If you’re having a hard time viewing the picture, just click on it and it will expand.
So does that mean my project is finished? Nope. In fact, this project is just getting started. I want to make some serious improvements to this circuit. First obvious improvement is by making the circuit as cheap as possible. For example, the MOSFETs I used for the circuit are really nice and robust (they’re rated around 150V/100A), but they cost $24 in total. Second, I must include an overcurrent protection circuit as it will prevent the MOSFETs from getting damaged when the motor is stalled. The next improvement is the inclusion of a undervoltage and overvoltage lockout to protect the Arduino from any possible damage. Not to mention, by adding overvoltage and undervoltage lockout circuity, I can forget adding an isolated DC-DC converter, which are really expensive. Finally, I will consider the project fully complete once I implement the circuit on an Arduino shield.
There’s another thing I want to look into. When I was running the motor control circuit with the motor attached, I noticed that my power supply went into current limit whenever I commanded the motor to make a sudden turn. This is due to the large amount of power needed to apply a torque large enough to change the rotation of the motor’s shaft. However, this solution can easily be fixed by implementing motor soft start code on the Arduino, which involves applying an increasing.decreasing PWM signal to the gate of the upper transistors to limit the power following through the motor.
Sorry for the short post today guys, but I spent most of last week preparing for my trip back to Philadelphia next week. I’m not sure if I will post a new update or a completely different article. Anyway, if you guys have any questions, comments, or concerns, feel free to post a comment. See you guys next week!