Found in a 1980s telecommunications documentation, the circuit presented acts as a product detector. The modulator or mixer in the square may be that of the previous circuit.
This SANYO circuit has a typical input resistance of 1ook9 and excites a load with a resistance of 5.1k...
The instrument of this field strength meter, from a 1970s publication, can be a 200 uA...
The sample and hold circuit used in analog to digital converters shown below was found in the...