This amplifier for electrometer can work with currents of 0.1 pA in a band of 1 Hz. The circuit is from NASA in a publication of the 60s. Transistors are general purpose types.
This Linear Technology cold cathode fluorescent circuit operates on power from 4.5 V. The...
This circuit was obtained from an American documentation from 1976. The circuit has a dynamic...
This circuit was originally intended to operate with a solar source for experiments. Transistors are...