This circuit is designed to measure very weak currents, in the order of picoamperes. We found it in an American documentation from the 80s. The integrated circuit is from that time.
The circuit shown is from a 1994 National Semiconductor documentation and can be implemented with...
This 1-transistor oscillator circuit was found in the March 1965 Radio Electronics magazine. The...
This circuit has been obtained from a technical documentation on filters from 1977. The...