BLDC controller trials

A project log for linear actuations for everyone!

cheap artificial pseudo-muscles here

CapitanVeshdokiCapitanVeshdoki 03/05/2020 at 19:040 Comments

I had an intention to use amazing PowerPak housings for transistors. And guess what? I managed to fail that twice by assigning things to a wrong pins. Firstly, I messed with a gate and after milling second version I realized that drain and source were swapped. So... I soldered TO-220 instead. Here is a picture of board's better years:

PCB at the bottom would serve as a measurement tool for testing bench, it has 12bit DAC and instrumental amplifier with adjustable gain to measure torque. More of that in next updates as there is some problems with that controller. It works, overall, but "rings" like crazy. Here is a photo with re-soldered FETs and voltage on transistor's gates:

Looks suspicious! I don't know what's the reason for that. Maybe, protective zener diode cause some problems. But the fact is that even without motor connected it drains noticable current and produces sound. Sound which is normally produced by a great currents flowing through tiny components. It's not a norm : )

P.S. Though, transistor opens as needed, shape of a current is an accurate representation of what we see on the gate, I presume - driver works fine, but frequent switching caused by ringing (around 1MHz) overloads it. Will see!