This circuit was found in 1967 Philips documentation. It uses transistors from that time. Transistors can be replaced with modern equivalents.
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...