A simple video to answer a simple question

Oh that’s lovely!! I’m so gonna steal this idea 😏 (to use in an enclosed power supply box of course…)

To badly paraphrase Kierkegaard, the real challenge is both going back into the box, and again leaving it. Schrödinger allows for both to happen at once.

Stephen Gillie

I am not entirely sure what the mechanisim used in these is, but If anything would utilize the holes in the end of the plugs, I would expect this to.. https://www.dewalt.com/products/accessories/miscellaneous-accessories/instrument-accessories/50-ft-123-lighted-locking-cgm-extension-cord/dxec14412050

Even in 1904 Hubbell was designing and patenting retention features for blades so a cord wouldn't fall out of the light fixture adapter one had screwed into a light socket. (!) "Under certain conditions of use the frictional engagement of the contact-plates with the knife-blade contacts is sufficient to retain the cap in place. Where, however, the conditions of use are such that there is an appreciable strain. tending to separate the cap from the base. I provide locking-springs 32, which are each provided with a projection 33, adapted to engage the recess 27 in the corresponding knife-blade contact, as is clearly shown in Fig. 3." https://patents.google.com/patent/US774251A/

https://patents.google.com/patent/US1146938 25: in order to insure perfect electrical contact with the corresponding alined knife blade contact and if the heads of the alined knife blade-contacts are provided with holes 19, the bosses will register with and engage the holes.

I enjoyed the video but.... it's all based on modern outlet designs. Not a single antique two prong (un-grounded) outlet was harmed in the making of this video. The 1920's house I grew up in was knob and tube, cloth insulated wires, push button light switches and not a single grounded outlet to be found. Modern NEMA outlets are likely required to meet a minimum specification for how much force (in foot pounds?) is required to pull a plug free. There may very well have been brass bumps or some other sort of stamped mechanical detail that functioned as a retention feature in early outlets. The lack of their presence in modern outlets is simply not evidence that they were never there. From Wikipedia (I know I shouldn't believe everything I read on the internet): In 1912 Hubbell rotated his tandem pins by 90 degrees to arrive at the parallel flat pin configuration still widely used today (NEMA 1-15). A feature common to all of Hubbell's patented designs is the provision of detents to retain a plug in its socket.

Bingo. In a pinch you can use a zip-tie through the holes to block insertion and attach a note when the appliance is INOP or being repaired.

lohphat

I hate to be that guy, but... you spelt Schrödinger wrong in the subtitles. I'll get back in my box now. (Or will I?)

Martin Deutsch

I was foiled by the spam filter on youtube, which lately removes about half of my posts even when they contain no links and no questionable content whatsoever, but here goes... Devices that lock plugs *out* so that they cannot be inserted: https://patents.google.com/patent/US2664734 https://patents.google.com/patent/US5055057A

antibrevity

On a different note, many of the pre-gelatin photographic procedures are still being done.

Timothy Kepple

When you said, "I'm going to plug it in ... slooowly." I was unexpectedly, slightly, turned on.

Timothy Kepple

https://www.amazon.com/dp/B0014ZXWCS/ref=cm_sw_r_cp_api_glt_fabc_CR1P7ZCWWX8NZ84FATSZ?_encoding=UTF8&psc=1 But even a cheap luggage lock will work.

I was always told the holes were to lock out the plug.

I would have guessed that the holes are there to make the pins more stable. Thin metal with holes in it bends far less easily.

Robert

Regarding old photography techniques, I don't know if this will be helpful, but this video from 2015 demonstrates making a tintype: https://www.youtube.com/watch?v=T_gQgkCfj7w I was there in person and the main thing that I remember is that the chemicals smelled horrible!

Michael Dunn

NEMA toads....lol :)

Erik Granlund

I think most US sockets have both screw-on and spring-loaded connectors for the wiring. https://inspectapedia.com/electric/Back_Wired_Receptacle_552_DJFcs.jpg

nobody

You can save a bit of copper with the holes.

I was electrocuted several times as a child because of the design of US plugs. Now that I think of it, that would explain a lot...

The way the cable attaches to all those sockets looks so old fashioned. Just a screw and you wind the wire around it hoping the wire does not slip from under the screw. Even in the 70's the UK sockets had a hole with a screw to grip the wire which seems much better and now Wago style spring loaded terminals are common in Europe. Not in the USA though it seems.

Richard Bevan

Having tripped over the cable for the hoover many a time, I can confirm that a loose plug is definitely not a worry in Britain! I think it's more likely that the cable will cleanly slice off my foot than the plug coming out!

So from my perspective I would also have said the wall connections don't feel very solid in the US (or any two pronged plug nation), but this is probably because I'm British (your least favourite nation when you do electrical videos?) and the three pronged plugs can't wiggle very much if even partially inserted and always seem solid and require some effort to insert and remove, even on trains used very frequently (sometimes these don't work, but that's not due to the socket in my experience).

Amy MacDougall

Did you even watch the movie?

MrHammond

Talking about safety: I remember those US plugs mostly from Hammond organs: they were built up to 1975, and even the European (50 Hz / 220 V) versions came with US plugs for some reason. They came then with a simple adapter, two prongs connected with blades, held together in a 2-piece plastic (bakelite?) holder. Of course, this plastic would become brittle in time. I once tripped over the power chord of a Hammond organ, the adapter was ripped apart, the prong/blade parts remained in the wall socket, I had to carefully get them out with well-isolated pliers...

MrHammond

The 2-pole unpolarised Europlug also has that, the downside is that the conductors are smaller, I think they are rated only up to 2.5 A... In Switzerland, we have almost identical plugs, but with solid metal prongs for unearthed equipment up to 10 A.

MrHammond

You got it all wrong, the holes are definitely for this purpose: https://imgur.com/rsAXDTE Sorry (not sorry) for any lasting nightmares that might arise from this sight

Kilrah

I've never seen a US plug up close, so I'd never spotted they even HAD holes! You could do an hour on our UK plugs!

Brad Jones

I also took an Amtrak sleeper early this year and found the worn-out outlets to be a big annoyance. I ended up bending the prongs on my charger inward to keep it from falling out.

Brady OBrien

Yeah I see the one you're talking about - that's really interesting since China does use the regular NEMA type A plug (along with C and I). I'm guessing there's something slightly different between the two that technically makes them incompatible from a standards perspective, but would work regardless since most things have lots of tolerance built in.

Ian Spence

Mainland China uses the unpolarized NEMA two prong plug, without the holes. Interestingly I have a bunch of Apple 5W power adapters from China and the US, and they are pretty distinct regarding whether they have holes or not. So if there’s a factory manufacturing a bunch of those things with the holes, there’s at least another one making them without the holes, in the same quantities if not more.

I have in the past used the holes to run wires through, so as to power a device from a non standard source. Let’s call it “prototyping”.

nobody

This reminds me of my very old Apple World Travel Adapter Kit, which includes two NEMA-like adapters. One is described as "Flat Parallel Blades with Holes, North America, Japan" and the other "Flat Parallel Blades without Holes, China". Other than the holes they appear identical, and I've used them both in American outlets with no problems whatsoever.

The Australia/Oceania/Parts of China type I style connector also uses thin, flat blades and would presumably also face similar manufacturing requirements, but I've never seen any with the holes. Also, they now require insulation at the plug end of the blade to help prevent the half inserted, but live plug problem. I wonder something like that possible with US style plugs? A lot of safety to be gained by the application of a bit of insulating paint.

Gavin

My father collected nineteenth century photographs from the late 1970’s on. There are a lot of active collectors and more than a few modern daguerreotypists too.

Another question: why does Japan fairly consistently *not* have them? And what's the deal with Japanese electricity and electrical connectors, in general?

Elsie Hupp

I always figured that daguerreotypes were exceedingly rare and expensive, as they are the oldest (?) photographic method. Plus having a daguerreotype portrait made would be a strange new thing that was prohibitively expensive for the common folk as well as being considered a frivolous vanity. Maybe I've been misapprehending what society was like 180 years ago and there were plenty of early adopters who marveled at the new technology and there were also plenty of folks who followed a hot new fad just as they do now.

Mark Hesse

I talked about an extension cord I had which did this, but deleted that paragraph as it collided weirdly with my voiceover insert. I also mentioned how the mechanism wore out quite quickly as it was plastic, but it was handy while it worked. Used it with an electric lawn mower back in the day.

Technology Connections

Random (other) thought on why we might still have them, since I feel the same when I come across an un-hole-y plug and it looking weird; if there is indeed a factory out there pumping out prongs by the gadjillions, and they need to be transported from there to another location where they're actually used in a product.The difference in weight cumulatively might be significant enough to affect the cost of transport. If you get them by the case, or by the semi-trailer load, it surely adds up, no?

Hugo Dahl

Amazon has “Clear Power 80 ft Outdoor Extension Cord 16/3 SJTW with Lighted Locking Connector, Black, Water & Weather Resistant, Flame Retardant, 3-Prong Grounded Plug” DCOC-0128-DC https://www.amazon.com/dp/B08B49ZQ3V/

Blargity Blarg Blarg

I have an extension cord (10ga) that has a socket end that locks. I’m interested to know how it locks… hmm..

Blargity Blarg Blarg

My suspicion was going to be for lockout, but the hole isn’t big enough for a typical lock and it wouldn’t be a great idea to use a metal lock with a metal key. It’s probably better just to use the plastic cans. Airports and hotels are always terrible. Only recently I’ve started seeing less of those alarm clocks with the old iPod connectors, so those lamps are probably at least that old and getting daily to weekly cycles.

Evan B

ehh, I rather it be 20 minutes than 2 minutes. I like your rants.

I’ll be watching it later on but that title made me crack up. Please leave that for the public release

Andrew Clark

So I wonder if something like this is using those holes, since it claims you can't remove it without a key: https://www.bradycanada.ca/lockout-tagout/electrical-plug-lockouts/stopower-plug-lockout-pid-65673

Ian Spence

NEMA toads. Platinum joke level.

Including a detour through the history of outlets before grounding (or "earth"), and "why there's always a bigger/taller/different side on 2-prong appliances". To be fair, when I saw the thumbnail in the email, but before reading the words on it, that was my thought!

Hugo Dahl

Why I'm expecting the video turned out that long because of a long winded rant on the terrible design of US plugs and sockets...

Guy Mendes