This 50 Hz rejector or notch filter was found in a 1975 documentation. Other frequencies can be obtained by changing components. The filter uses a Wien network and must use a symmetrical power supply.
This circuit is from the 1977 RCA Linear Integrated Circuits Manual. The circuit has a...
This circuit was found in 1980's Radio Electronics. The circuit produces a 1500 Hz modulate 35 kHz....
The maximum power of the controlled load depends on the triac used. The circuit is from a Radio...