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 circuit uses one of the first commercial transistors, availble in 1958, year of the...
This circuit was found in 1966 General Electric documentation. The circuit uses components from the era...
This circuit uses a FET to drive an LED with constante currente. The current up to 20 mA can be...