Amazing! An (old!) electrical device which performs roughly the same function as a transistor or a vacuum tube -- yet is constructed in a way similar to a tran

Amazing! An (old!) electrical device which performs roughly the same function as a transistor or a vacuum tube -- yet is constructed in a way similar to a transformer... Perhaps this device would offer a way to understand the electrical switching that a transistor does, not in terms of NPN or PNP junctions/dopants/charge carriers/etc. -- but in terms of more fundamental electromagnetic concepts, i.e., coils of wire, iron cores, magnetic fields, electrical fields, etc. In other words, what can be done with NPN/PNP junctions/dopants/charge carriers etc. -- should also be able to be done at a more fundamental level, using only wires, inductors, coils, iron cores, etc. This device (the "Mag-Amp") seems to do exactly that(!), and for that reason, I consider it worthy of comparative study...