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.
This circuit was found in documentation from the 70s. The transistors are from that time, but the...
The circuit in the figure alerts you when the frequency of the pulses applied to your input, which...
This alarm circuit is from a 1987 publication, however the components used are still modern. The...