In the last weeks I followed an idea to measure current without the need to cut the wires or even open a pcb trace. The solution i came up with is a hall effect based measurement.

I wrote some more about it in an article here: http://avrs-at-leipzig.de/dokuwiki/en/prokekte/fluxprobe

If you do not like to open the full arcitle here you can review the basic schematic as well as to see a foto of my first prototype:

schematic of the prototype

Foto of my prototype

The first but still impressing measurement:

flux probe measurement at 10Hz

flux probe measurement at 10Hz, 10ms/div, red: output of probe at 200mV/div, yellow current at 33,3mA/div