voltage tester
DMMs are usefull but for some things they are a bit inconvenient and bulky. So for fun and less so for potential usefulness i bought the 8 in 1 voltage tester depicted below, smaller than a DMM, puts a small decreasing load on the tested circuit allowing things like GFCI testing and so on.
But when testing at 220V AC it produced:
In fact the 380V LED lights up down to 175V.
Opening the thing up without destroying it proofed to be some effort, the inside:
I was already starting to trace things and draw a crude schematic to debug this when i noticed:
A unpopulated component, for a fraction of a second i considered a optional features quickly discarding that in favor of the hypothesis of excellent quality management in this ultra high end (it cost almost 5 euro) tool.
So after a bit of thinking, guessing and testing i wanted to solder a 100k resistor in there but my 10-15 euro variable power soldering iron didnt work anymore. That one was even from a local shop not ebay. Luckily i still had my grandfathers soldering iron:
Which after exchanging the tip worked perfect:
and after that all voltages work fine, including 220v:
PS: Recommendations for a good and cheap variable power soldering iron are welcome! ;)