So below is a "Portable Emergency Stop"
Basically where I live, central house installation GFCI are mandated since the 80ies.
Meaning they are the first thing in the breaker board, even before the breakers themselves, protecting the whole house.
So this simply triggers a ground fault. (with some diodes and caps, rather than merely a resistor, for technical reasons, but let's focus on the concept)
What would be the use case:
- When doing DIY, if things go wrong, someone else can press the emergency stop, without getting close to the out of control device.
(also applies to people doing lichtenberg wood burning and other MOT related stuff. Someone else can turn it off remotely, but not as far remote as having to run to the breakerbox)
My use case
- I have a brand new (to me) 1950 Lathe, and it did not come with an emergency stop
- Then I realized my drillpress, also did not have one. Nor my benchgrinder (Also none of my handtools, but those simply need to be released to stop.)
- Maybe I am simply getting old. Seeing danger where I used to see opportunity and excitement.
Possible drawbacks:
- There usually are 2 or 3 GFCI circuits, make sure it's connected to the correct one.
- You'll also be sitting in the dark (some countries smartly mandate separate lighting circuits, but not here in NL, lights and power are typically the same circuit)