This 4-transistor timer was found in the April 1975 issue of Radio Electronics magazine. It uses both single-ended and single-junction transistors to provide a dual audio output.
This traditional configuration was obtained in a 1986 publication. The speaker can be replaced by a...
This circuit from an old documentation (1970s) combines the function of cutting or limiting the...
This circuit is from 2002 documentation, requiring a symmetrical source of 6 to 12 V. The signal...