This 1000: 1 voltage-controlled filter circuit was found in an Electronics Today International in a 1980s edition. The circuit is based on components of the time.
This circuit emits an audible signal when the mains voltage ceases. The circuit is from a 1973...
This circuit, fully transistorized, brings together in a single device three functions of great...
We found this circuit in a 1972 publication. The circuit is indicated for the application of TTL...