Hi
I am digging into mains plugs, specifically the Europlug:
The Europlug has 4mm diameter of the tip of the pin on the plug (point B in the drawing below), and a recess on the middle of the pin where the diamet er is 3.5mm (point A in the drawing)
Some other plugs has 4mm diameter for the entire length of the plug
I am trying to find the reason for the recess, specifically if it is really needed
Since other plugs are all the way up to 4.5mm, I would expect the contact r esistance of the Europlug to be unchanged even if there are no recess. But it may be that in some obscure socket, the mating pins are dimensioned so t hat if the recess is not there it will increase the contact resistance (due to conflict with some mechanical part)
Any hints?
Cheers
Klaus