This adjustable circuit from 0 to 200 nA was found in a 90's EDN. The components can still be found relatively easily, as they are CMOS.
We found this circuit in an English documentation from 1995. With it it is possible to measure a...
This circuit is from an ancient American documentation. The coil is frequency dependent and the...
We have here a simple signaling circuit for two common incandescent lamps, which is used for...