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.
This circuit is from a Radio Electronics magazine from July 1984. The transistor determines the...
This circuit was found at Electronics Now. It can be used as a shield detector for dial signals in an...
This circuit was obtained from an English circuit manual. Components are common and LEDs can be 3...