This circuit is from National Semiconductor using an LM11, which is uncommon nowadays. The circuit can be implemented with other operational ones.
Found in Elementary Electronics from 1970, this circuit is a toy for generating different types of sound...
To obtain rectangular 1 kHz signals, we can have a simpler configuration, with a single amplifier, as...
We found this circuit in a 1977 National Semiconductor technical documentation. The circuit has 4...