This small tone generator was found in the November 1987 issue of Radio Electronics magazine. The phototransistor is common and controls the sounds generated. The basic frequency is given by C1.
This circuit was found in a 1992 publication. Its purpose is to time the activation of a doorbell...
This automotive circuit was found in the June 1997 issue of Electronis now magazine. The circuit uses...
This oscillator was found in the January 1996 issue of Electronics Now magazine. The frequency is given by...