Found in a 1965 Electronic Design the purpose of this circuit is to control the gain of a stage by applying an external voltage. The circuit operates at high voltages.
This filter was found in the October 1969 issue of Radio Electronics magazine. The frequency...
The circuit in the figure has the same purpose as the previous one (CBV15991E), except that it has a...
Found in a Popular Electronics from the 90s, this circuit can be adapted to use LEDs. The power...