This circuit is from the National Semiconductor's Linear Applications Handbook of 1994. The circuit can be implemented with equivalent operational. The detected voltage is given by the diode.
This circuit is valid for 106 series SCRs and can be modified to operate on the 110V power grid....
Found in an October 1992 Radio Electronics magazine article, this circuit generates a low-power tone in...
This circuit was obtained in a Popular Electronics of the 90s. The circuit is compatible with...