This circuit was found in a 1980s US publication. It indicates when the phone is off-hook by triggering an indicator.
This is the traditional configuration of a 6 or 12 V source with 7806 or 7812 integrated circuits, for a...
Found in an Electronic Design from the 90s, this circuit uses high voltage operationals of the...
This reaper or signal limiter can be used to convert a sinusoidal signal into a square. The...