This Linear Technology circuit can measure currents from 100 pA to 100 uA. The circuit is from the 80's, using a component of the era. Transistors are general purpose types.
This metal detector was found in a 2001 Poptronics, but it can still be easily assembled, as the...
This circuit for 6 lamps was found in old American documentation. The supply is of high voltage...
With this circuit it is possible to have a safe indication of the balance point for the signals of the...