In article ,
Brian Gaff wrote:

The daft thing is that apparently even Fridges in some cases are computer
controlled these days. My Remmington Shaver says it has a computer
controlled digital motor. Certainly it runs at the same speed for a very
long time then cuts out when it needs charging, so it obviously has some
kind of batter management system inside it.

"Digital Motors" are brushless DC motors, so they need some sort of
active control to get the step sequence right.

The speed thing is likely to be better battery technology, although
I suspect a clever system can have the motor spec'd to run at best
speed with less battery volts than the battery can supply, so that you
get what appears to be a bit more longevity at full speed as the
battery runs down.

All this can be done on a microcontroller the size of a pimple these days...

Gordon (wet shave, no power required)