This additional bell circuit was found in the February 1994 Electronics Now magazine. The transistors are common, and the circuit is for analog lines.
This circuit can be applied to several logics. The circuit is from an Electronics Now from the...
This simple circuit with SCR and unijunction transistor appeared in Radio Electronics magazine in July...
This timer was found in a 1980 publication. With the BC548 for Q1, an 8-ohm speaker with 6 V power...