A few weeks back I was looking for an USB-C soldering iron to replace my previous one. While documenting the pros/cons I stumbled upon some interesting knowledge: Switching Mode Power Supplies are awful.
You may experience it when using a laptop with a metal chassis: if you use it long enough and then you touch some metal objects connected to ground you’ll get zapped by the static electricity.
For soldering irons this means that your soldering tip will have a voltage differential of around 90V to ground. The current will be really small because the secondary/DC circuit is protected by a small capacitor, so it’s technically safe for humans. You can’t say the same to fragile electronic components, which will sometime fail due to the ESD. One simple precaution is to use a power bank when soldering delicate components.
There is another solution:
The doohickey
(Remember to use the name of the manufacturer if you don’t wanna end up reading about soviet tanks)1
This is an option ig, with people really going through this route 23. Other suggestions are the Apple USB-C chargers with a 3 pin plugs.
Causes
For more information on why this happens Wikipedia has a nice reference.
Demonstration
Video demonstrations, found thanks to this reddit comment.