I have described The STEMpunk Project as “an exercise in black box reduction”, by which I mean the project’s bread and butter is making sense of the previously mysterious inner workings of the objects which make up daily life.
Recently I took this phrase more literally by ripping apart a malfunctioning box fan. As it had sputtered to a stop in the heat of a June day I thought I might try my hand at fixing it, or at least divining how it worked. After pulling the coverings off the motor I took one look at its components and, not seeing any belts or pulleys, immediately thought “magnets are involved somehow”.
Some quick googling confirmed my suspicions. The blades in many types of fans are spun via induction motors, remarkably clever devices which utilize rotating magnetic fields to generate torque. There are different types of induction motors, but one common variant is comprised of three pairs of coiled copper wire which generate a magnetic field when current is applied to them. Applying current to the next pair generates a new magnetic field with a new north pole a few degrees away from the previous north pole. The same process is repeated over and over again in each of the three pairs, causing a disk or cylinder positioned at the center of the apparatus to spin along with the magnetic field.
I have found this process of gradually discovering the intricacy of things I’d previously taken for granted to be enormously gratifying. Learn more about induction motors here:
Learning Engineering’s “Electrical Machines” playlist.