This circuit lets through the 300 Hz to 3kHz range that corresponds to the human voice. We found it in the Radio Electronics magazine of February 1990. The circuit uses both parts of the LM381.
The purpose of the circuit shown in the figure, obtained from a 1972 documentation, is to delay the...
This circuit is used to match a high impedance input source with a low impedance output device...
This circuit of a 73 American magazine from the 1990s can generate multiple frequency signals from the...