This circuit is from a 1980's documentation for telecommunications. The circuit is used in SSB and the diodes must be suitable types for the application. The audio input is low impedance.
Found in a 90s EDN, this circuit is indicated for power control through a 4-20 mA line. The...
In the figure we have an improved method of varying the voltage of a 7812 regulator. The circuit is...
This circuit was found in an Electronic Engineering of the 80s. The circuit indicates when a...