This sensor circuit for currents of the order of nanoamperes was found in an American documentation from the 1980s. The components are from that time.
We found this circuit in an Australian publication from 1991. It is a kit of the time with input...
This time base circuit was found in the January 1988 issue of Radio Electronics magazine. The...
This circuit was found in the December 1983 issue of Radio Electronics magazine. The sensor is an...