When cost barriers drop, suddenly old problems start to look like new opportunities. There are many examples of older technology that has never become widely adopted due to cost constraints. The technology may be forgotten, but the problem that drove it still exists, and the application might still benefit from a new solution.
What happens when embedded motor controllers cost only $1? You can put them into old applications that didn’t make sense before. When reluctance motors were getting started, they were inexpensive to make and didn’t use any magnets. The plan was that these motors could be used in applications like washing machines where the speed torque curve could be changed on the fly for low speed, high torque for agitating, and high speed low torque for spinning the water out. In the 1980’s, however, processor technology was not that sophisticated and it required a $200 controller to make a small 1 horsepower system work.
Not so today.
Take the case of an analog tape player like an audio cassette. The tape is still around and really inexpensive. So are the playback heads, and there are some quality parts still in production for repairs. The player mechanics are a real mechatronic challenge that has some real nuances to deal with. As an aside, a lot of music lovers still prefer analog music signal sources like vinyl records, tape and vacuum tube amplifiers. So it may not be as crazy of an idea to resurrect the old tape player with digitally controlled transport hardware.
Using a state of the art Cortex M0 controller at $1 makes the solution simple, compact and straightforward. Since audio tape has very little mass, the motor needed to drive it can potentially be very small and inexpensive. Something from the toy world or a small Mabuchi motor would do the trick at $3. or less in cost. The key ingredient would be an encoder with the right amount of resolution to minimize velocity ripple. Add an inertial wheel to help dampen speed variations and you would actually be able to make the tape speed extremely smooth.
This is just an example where old ideas could become new again, and gain some unique traction in a world where we are still scratching the surface of what the digital domain can give us.
Crazier things have been tried, and made people very financially comfortable.