PSA: throw away any screwdrivers that are not isolated for > 1000V, in case you forget the one hand rule. Why? See below. #electronics
A little about me. Electronics is probably my #1 hobby. I hang out in chats and on mailing lists every day. Window #2 in irc client.
I have like a dozen tek scopes to back that hobby up. They're in boxes rn because I'm setting up my new space. Tall box is just plugins. 
I've lectured people on the one hand rule countless times. I've made pedantic designs of workbench mains circuits. I _know_ this stuff.
I also know you should have a GFCI, which I do. It has TÜV. It's not old or shitty.
TÜV are themselves known to be pedantic about safety yet this failed too.
I could have checked if the extension cord was energized. I was sure it wasn't, because I just pulled its plug from the socket.
I also worked on another extension cable just before and that was pulled, so that checked my subconscious "pull plug" instincts.
Thing is, with this one, i reconnected it for _just a minute_ to run the iron and solder something. Forgot all about that.
You know, I learned to solder when I was maybe 14. That's a long time now. Not a newbie to electronics.
Last but not least: this is my fourth time getting shocked. First two as small child, unable to appreciate the danger of his curiosity.
Third time when a door bell was badly installed on a fence. Live wires in the back. That one I should be dead, I held on with both hands.
I remember the feeling - I was unable to move, let go, I just froze. I tried calling the people around me, no air came out of my mouth.
That's more than half a lifetime ago yet I still vividly remember being unable to breathe. It's like a huge rock resting on your chest.
I've recounted this and other people's horror stories many times. Some got killed - or worse, maimed. I've seen the videos. I know the smell
When your spine was a conductor for mains and you can't control your toilet habits, that's not a pleasant smell to be around.
So you'd think, "he'd have learned mains safety by now" No. I just grabbed the first screw driver and went at it. Was sure it's not powered.
Not following the one hand rule, and no GFCI to save me, my left hand touched mains and my right hand was operating on neutral.
The one hand rule prevents death by making sure if your body does conduct mains, then it's not between hands - and through heart.
Yet all I got was a little scare. It didn't hurt. There's no burn mark on my finger, no redding. What saved me from death? Read on.
I bought the screwdriver over 10 years ago at a @maplintweet near Oxford Circus. It's part of @rolsontools 28737. It saved my life.
Always being pedantic about mains I developed an anxiety towards the normal screw drivers I used to use before.
Your hand can easily slip and touch the metal, and on mine the handle was smaller than my hand nigh ensuring it. Mine looked just like this.
That screwdriver was gone and I needed to buy a new one. I only needed it to open a pc. No mains there.
On that day, something told me to get one that won't have the failure mode wuere your hand can touch metal.
Plus, who knows if the plastic handle insulates against mains. Maybe, maybe not. Maybe they added cellulose filler for strength.
The Rolson, and in general any VDE screwdriver, is rubberized and has an insulated shaft. This prevents your hand from touching it.
It has ridges on the shaft which may catch and stop your hand slipping inside a device energized by mains and killing you.
It also is tested up to 1000V. If it were just 250V, and someone screwed up connecting phases, I could have been exposed to 360V and died.
In three phase power (common in households) the phases are sine waves shifted by 120°. Each is 230V to neutral (0V).
Due to the 120 degree shift in phase, the voltage between two phase conductors is >360V, iirc. Higher than normal. So, you test for 1000V.
Both of those things are normally unnecessary, as was my decision to buy a VDE screwdriver to open a PC case.
But the a screwdriver from the set I bought to open a PC case was the one I used to disassemble a powerstrip today.
Luckily it was one that was better than the bare minimum needed to open the PC case. That has saved me.
Two belts, three suspenders, and gaffa your pants to your waist. A little paranoid shopping for tools 10 years ago saved my life yesterday.
GFCI, mains plug pulled, left hand rule didn't save me yesterday.
Three life-critical safety mechanisms failed. Fortunately enough there was a fourth one, that was optional, saving my life. Learn from this.
You can never be safe enough. I got sloppy. Someone else might have made a mistake.
You can never be 100% sure of things.
If anyone tells you to cheap out on safety tools, kick their butt. It's your life. You might not need it today, but a time will come.
I didn't need this safety feature for over ten years, but on that day it saved my life.
Thanks for reading. If you came this far, consider retweeting+liking the top tweet so others can stay safe.
Here's a corollary rant about programming if you still need more geeky rants.
Here's the top tweet so you don't have to scroll all the way up. Let's get this message out to others.
I'm calling it. Bikers who were in crashes they shouldn't have survived get to put angel wings on their vests. We should have a thing too. Unless someone has better ideas I suggest a ring. You'd have to take it off before poking in electricity, reminding you of the one hand rule.
If you're interested in getting one, like this tweet. If enough people are interested, we can make it a thing. Or you can mail me at cheater 00 at gmail.
I don't know what the ring should be made out of. Ideas? Metal seems a bit Darwinian.
I suggest putting Fulgurite in it though:
en.wikipedia.org/wiki/Fulgurite
I suggest putting Fulgurite in it though:
en.wikipedia.org/wiki/Fulgurite
If it helps just one person be safer we've reached our calling as engineers. Our duty is to reach everyone.
Oh boy. Nuclear safety. Have *I* got a story for you.
If someone had told me one day I will have died if I didn't have an ad-hoc, 4-way redundant safety system, all while doing an everyday thing, I'd have thought they were downright loopy.
Probably a good time as any to mention that if you're looking for someone to do work with functional programming, blockchains, or machine learning, I can be hired to do all of that and more. Good with all sorts of tech. Just @ me
This guy was smarter than me!
Turns out being a professional and knowing better will not save you.
Oh fuck, I didn't even know that could happen. Can anyone confirm?
Would the pun be too cringeworthy if i gave a lightning talk on this
Should i do this
Any takers
Also we could call this a "post mortem" for bonus morbidity
Any takers
Also we could call this a "post mortem" for bonus morbidity
