This circuit generates rectangular signals from 2 Hz to 20 kHz using an operational amplifier. The circuit is from 1984 Radio Electronics. The power supply must be symmetrical.
This oscillator was found in the November 1986 issue of Radio Electronics magazine. The frequency...
This sophisticated circuit with a low, medium, and high treble filter is from 1990 documentation. The...
This circuit was obtained from a 1998s Popular Electronics. The magazine no longer exists, but the...