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 is the commercial circuit for the TRF-44 amplifier sold in Japan in the 1960s. The circuit...
This circuit uses a common cathode display and TTL integrated circuits. We found it in a 2001...
This circuit was found in a 1992 publication, using an operational amplifier not very common...