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 is a two-input audio switching circuit. The operational can be of any type and more entries can...
We found this amplifier for automotive use in the Philips integrated circuit manual from 1990. The...
Found in old English documentation this circuit can be made with a BF245 or equivalent. Coils are...