This circuit was found in an American documentation from the 1980s. The circuit combines filters of different types in a single structure, each of which can be programmed for a frequency.
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...