The reversing switch contacts tend to wear out with extended use and can be very difficult to service or to have serviced, hence the scooter's reputation for requiring roll starts later in life.
12.
One way to envision what is happening in an AC-to-DC rotary converter is to imagine a rotary reversing switch that is being driven at a speed that is synchronous with the power line.
13.
There was a bottom mounted reversing switch that would allow the robot to reverse when it touched a special plastic plate, or turn the robot off, when in backed up into its display case.
14.
The rotary converter is somewhat more complex than this trivial case because it delivers near-DC rather than the pulsating DC that would result from just the reversing switch, but the analogy may be helpful in understanding how the rotary converter avoids transforming all of the energy from electrical to mechanical and back to electrical.
