This circuit was found in an American publication in 1966. The circuit uses a general-purpose FET that admits an equivalent. The instrument is a 250 uA full-scale microammeter.
This circuit was obtained from an English magazine from 1976. The circuit activates a sensitive relay...
We found this circuit in documentation from the 1970s; The circuit uses Japanese transistors of...
Found in the September 1992 issue of Radio Electronics magazine. This circuit generates pulses that...