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.
We found this circuit in the May 1996 Electronics Now magazine. The relay must have a voltage...
The shield circuit shown is from the 1994 Linear Applications Handbook by National Semiconductor of 1994....
Up to 0.5 A DC motors can be controlled by this circuit. Direction change is achieved by a logic...