The time of this timer depends on C1. The circuit was found in the July 1994 Electronics Now magazine. The supply voltage depends on the relay and can go up to 12 V.
With this circuit it is possible to use a common hair dryer as a hand dryer. The circuit is timed...
This power supply was found in the same 1990 special issue of Radio Electronics Experimenter...
Suggested by an Electronic Engineering, this circuit uses components of the time. Modern...