A great example is this simple wireless AC current detector from [NEW PEW]. The circuit is a simple one, and a classic. The spring from a ballpoint pen is soldered to the base of a BC547 ...

A great example is this simple wireless AC current detector from [NEW PEW]. The circuit is a simple one, and a classic. The spring from a ballpoint pen is soldered to the base of a BC547 ...

using an inexpensive 8-pin chip as an ‘active shunt’ for measuring ac/dc current levels upto 20 Amperes. First of all, note that the circuit as it stands is only really intended to show how a basic ...