This circuit is for old telephones with analog lines. It was found in the May 1988 Radio Electronics magazine. The circuit is powered by the line signal voltaje.
Found in an old neon lamp applications manual, this circuit directly triggers an SCR. R and C...
This 20 MHz bandwidth circuit was suggested by the National Semiconductor in 1970 documentation. Modern...
This circuit cuts out ads between songs, based on the fact that the speech signal has small...