- Published in issue 9/1995 on page 78
Mains measuring aid
The mains voltage level is dangerous, and possibly lethal to touch, so that extreme caution is required whenever you work on wiring or components connected to the mains. None the less, it is sometimes required to investigate the shape of the mains voltage using an oscilloscope, for instance, if you want to measure the mains current consumption of a device, or establish the degree of mains pollution caused by a certain load. The circuit described here reduces the risks of connecting an oscilloscope input to the mains to a minimum.