This VCA was found in the July 1988 issue of Radio Electronics magazine. It uses an OTA op amp and has its gain adjusted by the voltage at the gain input.
The great advantage of the circuit shown in the figure is that its frequency is controlled by a...
This circuit can be used as a shield for microcontrollers. The circuit is from American...
Mounting an oscilloscope is the dream of many of our Internet users, although it comes up against...