These circuits were found in the February 1995 issue of Electronics Now magazine. The circuits have normal response in (a), boost in (b), cut in (c), and plate response in (d).
In fact, this circuit can generate 50 Hz or 60 Hz signals depending on the power supply. The input...
This is one of the many hysteresis comparator circuits the reader may find in this section and on this...
This 1995 documentation circuit detects when an extension on a phone line is active. Adjustment of the...