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 was found in a 1967 American documentation. The switching diode (tunnel) used is an...
This circuit was found in a 1975 documentation. Operational amplifiers must have a symmetrical source and...
The diagram shown was found in a 1975 active filter manual. The tuned frequency range depends on...