Found in an Electronic Design from the 90s, this circuit uses high voltage operationals of the time to excite a piezoelectric motor in a bridge circuit.
With this circuit it is possible to use a common hair dryer as a hand dryer. The circuit is timed...
This circuit was obtained from an English magazine from 1979, but can be easily assembled today...
This circuit was obtained in a 1975 magazine, but it can be easily assembled using BC548...