This analog telephone line extension circuit monitors when the line is in use. We found it in the November 1996 Electronics Now magazine.
This configuration, which requires a symmetrical power supply for the 741, can be implemented with other...
This timer with two unijunction transistors and one SCR was found in an American documentation from 1964....
This simple metronome, from 1985 documentation uses only transistors and has two settings. For...