dudefromthenorth on Is Your Movie Too Loud? Can’t Hear The Dialogue? This Circuit Can Help.Dude on The Coming Copper Shortage: Aluminium Or Carbon Nanotubes To The Rescue?.Posted in Misc Hacks Tagged BLDC, BLDC controller, brushless DC motor, h-bridge, hall effect, hall effect sensor, hbridge, motor controller Post navigation If you have a 3D printer, you can build an even better one. If you don’t have a brushless DC motor handy, you can always build your own from junk. You can find an updated schematic on the associated web site. If you decide to duplicate the circuit, note that the video has some diodes backward. The video has some very good animations that explain the sequence and the critical timing involved. The trick is how to sequence the coils so that you get the rotation you desire. The drive circuitry is just a few MOSFETs that form three H-bridge circuits.

A simple LM324 comparator and a few resistors took care of that. Normal motors with sensors have conditioned sensor outputs, but since this was a dumpster raid part, the hall-effect sensors needed some circuitry to drive and read them. Having these sensors simplifies the drive electronics considerably.

The motor in question was pulled from an optical drive and has three hall effect sensors onboard. If you want to know about using the motor’s coils as sensors, he did a video on that topic, earlier. Many motors have the sensors built in and shows how to drive one of these motors in a recent video that you can watch below. Or you can use sensors to detect the motor’s position. You can figure out the timing using a somewhat complex circuit and monitoring the electrical behavior of the motor coils. For the best result, you need to close the loop so your circuit can apply the right sequence at the right time. Driving a brushless motor requires a particular sequence.

Electronic speed controller