Found in an Electronics Now from the 1980s, this circuit uses some components that are still common today. For others, equivalents can be tested.
This circuit was obtained from a 1997 publication. It is an alarm that has a lock and a bistable...
This circuit is from a project published in the March 1996 Electronics Now magazine. The author used...
This well-known circuit is another version of a 2-transistor transmitter found on the Internet. In this...