Carl Bugeja has made quite the name for himself this year with his PCB motor prototypes. Unlike conventional electric motors that have copper wire windings, Bugeja’s designs put those windings on the PCB itself as traces. The benefit is that a maker can inexpensively integrate low-torque electric motors into their projects without having to add a electric motor to the bill of materials. Now Bugeja is updating that concept to include a built-in ESC (electronic speed control).
An ESC is necessary to, well, control the speed of an electric motor. Without an ESC, the motor will just spin at an unpredictable speed that will fluctuate with the power supply. Most off-the-shelf ESCs, like you’d use for a drone, work by measuring the current as it increases with the magnetic field generated by the spinning motor. To retain a specific speed, the ESC simply modulates power to the motor. That doesn’t work for Bugeja’s design, however — likely because the traces don’t amplify the magnetic field in the same way as traditional windings.
So, Bugeja built in a hall effect sensor instead. As the motor spins, its magnets pass by the hall effect sensor and trigger it. How often that happens can be used to calculate the speed. That’s done with a PIC16F1503, which monitors the speed and controls the power through an STSPIN230 triple half H-bridge driver. With those, the motor and the controller are all built into a single small, cheap module, which would be useful for a lot of projects.