Found in a 1960s documentation, this circuit uses an operational amplifier from the time and a current diode, both of which are difficult to find today.
This amplifier was found in a 1957 Rayrtheon documentation. The circuit can be fitted with a BC558...
This circuit was obtained from the May 1971 issue of Radio Electronics magazine and is intended for...
Although it is a common configuration today, this circuit was taken from an old publication. The...