The transistor in this project found in the July 1994 issue of Electronics Now magazine can be any general-purpose type. The circuit is powered by the relay voltage up to 12 V.
This circuit was found in a Radio Electronics magazine from November 1991. The circuit operates at 2.2...
This relay circuit with a dual channel MOSFET (not very common today) was found in an old American...
This circuit is from a 1980s Motorola documentation. The circuit can be made with modern...