The input and output frequencies of this circuit depend on the coils and capacitors of the tuned circuits. The circuit is from Electronics Now magazine, February 1997.
This counterphase circuit is from a 1973 publication, and can work with mains voltages or 12 V....
This circuit can be used to directly control direct current loads or higher alternating current loads...
The acquisition of data, from a transducer, so that these data can be converted to digital form...