We found this circuit in a 1991 Hobbyst Electronics. The circuit makes use of an unusual transducer today. It is a piezoelectric buzzer that can eventually be replaced by an equivalent configuration.
This source was obtained from a former publication for valves but also serves for powering common...
This circuit was found in the March 1994 issue of Electronics Now magazine. The circuit uses a...
This circuit activates a water pump when the sensors detect lack of humidity in a vessel, for...