This high impedance circuit was found in 1967 documentation by Ferranti. The original operational amplifier is from that time. The circuit can be implemented with modern equivalents.
Found in a Maxim documentation from the 90s, this circuit produces a voltage of 5 V from an input...
Unlike the previous one, this circuit is intended for the reception of frequency modulated signals...
This circuit was obtained from Popular Electronics from March 1967. The transistor used is from...