Brilliant design: RCA student radically improves the UK plug
iconeye.com
iconeye.com
The reason plugs in the UK are so big is that each one must be individually fused. And the reason for that is something called a "ring circuit".
In a ring circuit you have, say, a 40 amp fuse at the mains/box. From this you send out two wires, each rated only for 20 amps, going in a circle around the house. You can now supply 40 amps worth of power using only cheaper 20 amp wires. (Since the current can flow over both wires at once.)
But this means that the wires going to an individual appliance are far too small for the main breaker, so each appliance gets a fuse in the plug.
Ring circuits have serious drawbacks, but they helped during a time when there was a copper shortage.
And ever since then the UK has been stuck with huge plugs.
They tend to rest on the plug's back, and hurt a lot when you step on them.
> Any other countries use them?
India and South Africa use the so-called Type D plug[0] (also called Type M in its 15A incarnation), which is similar but uses round plugs (type D is actually an older english standard). Some other south-east asian countries also use Type D. The english plug is called "Type G" and used in a number of former colonies and protectorates[1], especially in Africa and the Middle East.
[0] http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#Type...
[1] http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#Type...
I wish someone would come up with a design which doesn't hurt so much when you accidentally tread on one.
http://www.minkyu.co.uk/Site/Product/Entries/2009/4/20_Foldi...
The promo shots of the final working model don't show how you get at the fuse, but I'd be very surprised if it has been overlooked. I suspect it's something to do with the red dots.
Indeed, the red dot is the plug cover. This set of blogspam pictures don't show it, but previous sets (the folding plug first made rounds in mid-2009) showed how the plug works. You can see an "action shot" simulation of the plug in the video: http://www.youtube.com/watch?v=f6DvjKkGT6s#t=1m46
Given a choice between US plugs (spark, fall out of sockets, flimsy, dangerous, bendy pins), and UK plugs (Built to last, don't spark, fused, solid) I know which I'd choose.
There's also large advantages to having each plug individually fused - individual appliances blow rather than the whole circuit.
So I wouldn't say we're "stuck with huge plugs". The only real time it's a slight issue/pain is when you go on a plane and the cables take up a bit of space.
"The only time its a slight issue"???
How about manufacturing, shipping, selling, storing, repairing, and paying for that overdesigned eyesore? How about looking at it? How about moving the couch out from the wall so the dang thing will fit back there?
* trip up a cable, and the plug falls out of the wall
(Pulling a UK plug out required force. It will not pull out)
Plus the cable exits a plug pointing downward, which
means it will not pull out via the cable.
* Sparks when you put a plug in or out.
* Bent pins that look like they're about to drop off
* No shielding on pins
* Often no mechanism to stop things being put in sockets
(All UK sockets only open once an earth pin has gone in
Also, when you decide to put a lamp somewhere, you typically make sure the cable is not somewhere that can be tripped up.
But as I say, all rooms in the UK come with a fitted ceiling light, and a light switch by the door. So lamps are less common.
Ok, the alarm clock. or the hair dryer (into the bathtub! Yay!) or the wireless access point...
Hairdryers are usually used in bedrooms.
The last time I tripped over a cable was..... years ago. I can't even remember doing it. It's not an issue we have.
Yes, they do. (The UK, or even Europe, is not the whole world.)
> Hairdryers are usually used in bedrooms.
Hairdryers are used in bathrooms if there's a plug in the bathroom.
Sockets do not exist in bathrooms in the UK.
It is usually, but does not have to be, an overhead light.
An alternative that is also code-conforming is to have the switch control a socket (typically, the bottom plug in several duplex receptacles in the room) where a lamp is plugged in. Sometimes people don't actually plug a lamp in there, so the switch does nothing, and maybe that's what you've been irritated by.
If the wiring is done this way -- e.g., bedrooms and living rooms -- it can be quite flexible if you want to rearrange the room layout. You move the furniture and plug the lamp into the bottom receptacle where-ever it is convenient and sensible.
Cars kill 100 times more people than electrocution (not to mention severe injuries, which are rare for electrocutions), so they're probably a more important risk to worry about. Any slight difference in car accidents is going to swamp electrical concerns.
The latest source that I could find said that 400 people died of electrocution in 200, down from 670 in 1990.
I wasn't able to find any information on the UK. However, being from the US, I'd probably bet your wiring over there is safer.
> * trip up a cable, and the plug falls out of the wall
> (Pulling a UK plug out required force. It will not pull out)
> Plus the cable exits a plug pointing downward, which
> means it will not pull out via the cable.
> * Sparks when you put a plug in or out.
> * Bent pins that look like they're about to drop off
> * No shielding on pins
> * Often no mechanism to stop things being put in sockets
> (All UK sockets only open once an earth pin has gone in
I prefer the UK plug too. But you missed one other very important point of pain: the pain of standing on one. As the flex on a UK plug leaves from the bottom, it has the unique property of tending to lay down on the floor with pins facing upwards.
That would be the point. Better to damage a plug slightly than get the plug through your feet.
16A at 240V in a grounded plug that is very easy to protect against tiny fingers and that you'd have to be trying real hard to get your fingers on when inserting it, even in pitch dark.
Forwards compatible socket with the Euro plug. (that's the thin, ungrounded one with just two pins, one live, one neutral).
It will do anything from your phone charger to a light duty welder.
It's not really that it's forwards-compatible, but that the europlug was created specifically for this purpose. It's compatible with all european sockets but the english one I believe.
http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#Type...
Edit: I'd just be happy if Europe picked a single standard and stuck with it. It's ridiculous to have to carry all sorts of converters for what are, in the grand scheme of things, not very long trips.
There is a mechanical/electrical machining process called spark erosion aka electrical discharge machining. Every time you have a spark a tiny bit of the metal of both contacts evaporates. Of course that's when you want it to happen, in sockets with plugged in loads you really don't want it to happen.
Over time this process accelerates and it has been the cause of many house fires in the US.
The fact that such sockets are placed in walls made of mostly wood placed right next to an upright stud does not help either.
Sometimes they're so bad you can actually smell the ozone.
And sparks are not the cause of many house fires, you just made that up. The sparks are harmless, and I've never seen a plug with erosion on it. Just because you can do it doesn't mean it actually happens.
American plugs spark (much) more frequently and strongly than their equivalent UK/EU plugs because the spring pressure from the side contacts is insufficient to maintain good contact over the lifetime of an installation, especially if the plugs are also worn. The fact that typically the current is twice as high doesn't help either (though if you get zapped it's less of a problem than in 230V installations, the US uses a balanced 110 system for most residential circuits where only a few receptacles which are of a different design have both sides of the step-down transformer outside of the house running to them).
The UK/EU plugs are of a much more solid construction than the American ones, as are the wallsockets they go in to.
I've seen US sockets that made an audible buzz while operating and get extremely hot (hot enough to melt the plastic). Not good.
The usual way in which it gets to this state is that a socket has been overloaded a couple of times, or heavy load is plugged in or removed while switched on, the contacts have corroded or have some soot build up on them and then the resistance increases enough to start a runaway process that ends with the socket failing altogether or with the socket getting so hot that the plastic outside cover will start to melt.
At that point all bets are off, especially in houses that are mostly constructed from wooden sticks instead of brick or concrete.
Another cause of trouble like this is that there was a short period when due to the supply issues with copper electrical wire made of aluminum was tried in residential installations in the US.
These required special fixtures so the wire would not come lose as the aluminum compressed over time thus shrinking away from the contact and causing an airgap and thus sparking.
This kind of wiring is no longer 'code' and if you have such wiring it wouldn't harm to periodically tighten up on the screws to ensure good contact.
Aluminum oxide build-up compounds this problem.
People always blame 'short circuits' for electrical fires, but most of the time this is nonsense, since the breaker will almost always instantly trip in a short circuit situation. That's what they're designed to do.
Half shorts (shorts that are of a resistance low enough to cause significant heat build-up and high enough not to cause the breaker to trip) and faulty contacts (intermittent contacts, sparks and thus heat) are a much more frequent cause of fire.
Another big cause of fire is counterfeit junk hitting the market and do-it-yourself types that don't know the difference using this to wire up that extra socket for a space-heater in the attic.
You have soot on your contacts???? Corrosion? Did it rain inside your house?
NEVER tighten aluminium contacts! You will cause exactly those problems that you describe. If there is a problem with it you need to remove it, apply the anti-oxidant paste and reinstall.
But aluminium to the contacts is very rare in america these days, where it does exists it's usually been pigtailed with copper.
Rural areas, farmhouses, but one building I lived in in Toronto had a problem (a bad one) with one of the sockets and it was a fairly recent upgrade from what I remember.
> You have soot on your contacts???? Corrosion? Did it rain inside your house?
No, simply an installation from the 70's still operating in 2005. There are millions like that. And I don't live there anymore, I'm back Europe now.
> NEVER tighten aluminium contacts!
Not over-tighten, tighten. You should do it to the proper torque (there are special tools for that).
> But aluminium to the contacts is very rare in america these days, where it does exists it's usually been pigtailed with copper.
Yes, that's the slightly newer method, also since outlawed (and used as a way to fix problems).
The biggest problem I think with the alu wiring was not even that it could not work, but that people would use it with the wrong connectors, the al specific sockets were pretty pricey.
The only place where I know that aluminum is still used in residential wiring is on the entrance wire from the pole to the transformer, usually that's a very tricky connector that uses wedges to make the contact.
If I found myself in a house with aluminum wiring I'd probably rewire the whole thing just for safety. Costly (especially with the US system which staples cables to studs) but worth the peace of mind.
The correct installation uses anti-oxidant to seal it, then you tighten it enough to crack the aluminum oxide, and the anti-oxidant protects it. If you tighten it without fresh anti-oxidant you are creating a hazard.
And pig tails are not outlawed - quite the opposite, they are the recommended way to handle aluminium wiring.
Ah ok, I see what you mean now, yes that makes good sense.
As for the pigtails, as far as I know you can not make any new wiring with Aluminum in residential installations, pigtailed or not (I left my code book in Canada because it is of no use to me here, maybe there is some up-to-date online resource). Industrial use is still ok I believe.
Yes. But if you already have aluminium wiring you can - and should - add pigtails to it to make it safer.
In my two months in the USA, I observed more arcs and electrical crackling noises than I have in the rest of my life in AU.
Just my anecdotal 2c.
But I could be all wrong, as I'm no expert beyond having a drawer full of adapter plugs.
Or did you mean that you only need to run one set of wire instead of multiple ones to multiple outlets?
I'm not sure why. Is the skin effect sufficient to explain this?
That uses way less cabling than any other network.
To that end, the live and neutral contacts in a British socket are shuttered. The long earth pin on the plug makes contact before the live or neutral pins are in the socket, and once in contact, raises a shutter to permit live and neutral to make contact. And the nether regions of those pins are insulated so that if a plug is halfway into a socket and something bridges the pins, it can't make contact.
This is a great design -- for space heaters and ovens and server racks. It's a bit less useful for the low power consumption devices that have come to dominate the market (where maximum draw is well under 1Kw -- often under 0.1Kw).
Of course, that does break down a bit when you get to fuses, since you now have to worry about using different capacity fuses for appliances with different expected maximum power draw (3A for most things, 5A for the odd high-power small appliance, 13A for anything involving a heater...)
I've only ever lived in houses with the big uglies.
All lightbulb headaches have been due to IKEA and their foreign ways.
That's not really true, you can still get electrocuted if you put you finger on both bolts.
And that plug is massive. Luckily you can use any sticklike thing to allow continental plugs to be inserted (which incidentally I'm doing right now -- hello from Edinburgh)
And since the pins are angled, even a two-pin version is pretty hard to accidentally wiggle free compared to the two round pin European plug (I think some European countries have extra bits as well that might help?). Definitely does not deserve comparison to the awful American plug design.
Mainland european grounded plugs pretty much all handle 15A/230V, and none looks like a battlecruiser (see the well-known and widely used "CEE 7/7" aka "Type E/F hybrid": http://en.wikipedia.org/wiki/File:CEE_7-7.jpg)
Wake me up when it actually gets implemented and becomes available for real.
Now I happen to think that this project has some merit, though the rotation of the two main plugs will never pass muster -- it'll break quickly and at any rate almost certainly will rapidly become a fire hazard internally after a few turns. But that's probably fixable.
But what I think the GP was getting on about, and what also annoys me greatly as well, is that there are many "designers" (i.e. artists) who think that engineering is the easy part, and what really matters is "innovating". The mindset of "designers" goes like this. "Let me think of this cool version of a chair! Now I just need to find a lowly engineer to do the menial engineering part, I'm sure it's inconsequential." Design-first-engineer-second is how you wind up with poorly engineered "innovations" like these: http://www.strida.com/en/products/
The basic problem is that most artists have no training in making something which actually works. It's not sexy to get something to work. It's sexy to draw pretty pictures.
When I was a little kid I used to draw spaceships where a lightbulb was focused through a long series of lenses until it became stronger and stronger and was blasted out the back, Star Wars Propulsion style. I was quite the innovator, and had some awesome spaceships with impressive lens sequences. That didn't mean my idea contributed to the global discourse.
Of course if you have used "e-gronkuiotis cloud 2.0" we would have funded your innovation with a squilliuon $
So for the case of automobiles, the designer is first, engineers second. Obviously the teams will work together to make compromises but it certainly gives merit to the power/value of the designer.
your statement is a gross generalization about "designers", biased toward "engineers", and completely ignores two facts; 1) great products are a combination of both, and 2) most products don't achieve greatness for a variety of reasons that may be unrelated to either party.
It's like plugging in a cascade of extension cords.
I don't like the mobile pieces either, they are:
- structurally fragile
- likely to break off and decrease safety
- in the case of the contacts a source of contact resistance
which causes energy to be lost as well as an
increased fire risk
- if they are 'wired' a spot where the wiring will break
because of fatigue issues
Electrical plugs are a source of some amusement in Europe, in spite of being a 'union' we are not even capable of designing a plug that satisfies everybody and for some this has become symbolic of the dissent in the various states against EU conformity.
Have a look here how crazy the situation is:
http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets
If we can't even design a common AC plug that everybody will actually adopt that's food for thought.
[1] http://en.wikipedia.org/wiki/Euro_zone#Members
[2] http://en.wikipedia.org/wiki/Schengen_Area#EU_member_states_...
As for ganging plugs, this approach has an advantage over other (e.g. American" standards - there is the possibility of keying the "ganged" plugs by rating, so for instance only 10-amp plugs could be ganged to the 40-amp main, thus preventing fusing issues.
I've seen multiple blackened areas around wall sockets in relatively new houses in the US and Canada due to ridiculously high contact resistance.
The fuse in these plugs - assuming there is one - is in series with the consumer, not in series with the pass-through to the next plug, so yes, by ganging them up you're bypassing the fuses.
That's kind of logical too, otherwise you'd have to be matching the plugs in decreasing order of load (which in itself would not be a bad idea).
Fragile because they have moving parts, anybody that has any experience with electrical stuff knows that as soon as there are moving parts involved in something as basic as a connector that you're looking at an increased failure rate.
Dangerous because they allow the users a degree of freedom that has led to lots of trouble in the past, to the point that 'gangable' designs in plugs have been outlawed in lots of countries.
The fuses in these devices can do whatever the one in the wall does, how can we tell by looking how it works?
As for moving parts, I wonder how that interlock in the wall-plate works. Also, seems like my two-year-old can stick a fork into the ground pin just as easily as any other. And current flows thru the ground, yes, that's why its called a circuit.
Dangerous - yes, if not keyed. That's kind of a cool idea, if its not easily defeatable like the ground on 3-prong cords in the US- they actually sell adapters in every hardware store that simply ignore the ground!
Based on this image:
http://www.iconeye.com/images/news_july_09/choi_uk_folding_p...
The contacts on one socket protrude in to the next. Which is also the most logical thing to do (otherwise it gets too thick). So no fuses between sockets, just three wires 'down' towards the consumer one of which is fused (the little red tab on the left).
( Disclaimer: I'm in the US and I've a three-way adapter with a cut off ground prong for traveling, so feel free to take what I say with a grain of salt )
There are 3 electrodes -- hot, neutral, and ground. Current flows thru hot to neutral (both slotted openings). The ground is the round pin.
It's true that, back at the panel box, neutral and ground are connected together. But, current should never flow thru the ground wire to get there! That wire is strictly a safety mechanism.
The relevant terms in the US electrical code (the NEC) are "grounded conductor" (neutral) versus "grounding conductor" (ground).
Only if you have only one panel. If you have multiple panels (aka pony panels) the connection from neutral to ground (aka the 'bonding connection') is made in the panel where power enters the premises.
Nah, it'll be fine. Actually this sort of thinking is probably because of the "dangerous plugs" pictures we are always shown as children. A stuffed up socket just looks automatically dangerous to us.
I guess you're coming from the perspective of overloading the socket. This is surprisingly hard to do - but you can do it equally well across multiple sockets (basically, if your fuse breaker is going to let it burn it doesn't care much where the devices are plugged in :)) so it is something of a misconception to consider a crowded socket particularly dangerous. People happily use an 8 gang extension cable without batting an eyelid.
More importantly having fuses in the plugs is unlikely to help all that much, the crucial fuse is the one in your circuit breaker. The current will divide across the sockets (my circuit theory is rusty so I won't try any figures :)) and it is the socket taking the brunt. While you would likely eventually see a spike that trips one of the plugs I'm betting the socket catching fire is more likely.
And, finally, I suspect these would be rated (well, if they weren't vapour-ware) for devices with internal fusing or low power draws. I'd also suspect that the plug "holder" would be fused.
BTW it is somewhat moot anyway because I believe those red tabs are a fuse holder :)
That's a lot of contact resistance, this socket already has twice as much contact resistance as a normal one (because of the twist in the contact section).
If we're talking 'light' consumers, say below a 100W or so you might get away with it but if a 'heavy' consumer would be plugged in as the last element in a series of 'light' ones you'd be concentrating an awful lot of energy in to a small spot.
But hey, what do I know about electricity ;)
At 10 mOhm (new and very clean) per contact with 5 plugs 'ganged' up that's 5x4x10mOhm or .2 Ohm. With a 240V working voltage and a 2 KW consumer that would be 8.3 Amps so about 1.6 V drop, 8.3x1.6=13 Watts, which the copper wiring alone can probably remove without any heat building up.
If the contacts wear and get older they could get to as much as .3 Ohm apiece. Now you're looking at 5x4x.3 Ohm, 6 Ohm, in total so that's a 49 V drop, almost 400 Watts to dissipate just in the contacts. That's a lot of heat.
That's why some older wall sockets will get warm (or even hot) when you plug in a large consumer.
And your circuit protection will not care even a little bit about all this, it's just another heater.
If we're talking 'light' consumers, say below a 100W or so you might get away with it but if a 'heavy' consumer would be plugged in as the last element in a series of 'light' ones you'd be concentrating an awful lot of energy in to a small spot.
Think about what is likely to have these sorts of plugs; Laptops, for example, usually pull under 2A. Which means you could have 10 plugged in before it starts to be a problem, and even pulling 20A to your socket (which is a common rating for mains sockets) still leaves plenty of leeway.
I'm not sure what my iPhone or radio alarm clock is rated for (am at work atm) but I can't imagine they add up to more than 1A draw.
As I mentioned, the problem on mains networks overloading comes, usually, from a faulty trip switch. If it is doing its job the most that you can do is trip it (and maybe fry some equipment that isn't earthed/fused properly). Stocking up a plug is pretty safe; again, as mentioned, it is easy (and more common) to overload the whole circuit via a number of plugs :)
EDIT: meh, it's impossible, anyway, for it to be set up in series, otherwise you wouldn't be able to pull power correctly.
with 5 plugs 'ganged' up Uh, there are three plugs in the design?
But this is a reasonable concern (the heat issue). In practice it is not too much of a worry, if a device is demanding 2KW this plug is clearly unsuitable (for a number of reasons).
The contacts are in series:
live->socket1->socket2->socket3->socket4->socket5->load
|
|
neut<-socket1<-socket2<-socket3<-socket4<-socket5<-load
> Think about what is likely to have these sorts of plugs; Laptops, for example, usually pull under 2A. Which means you could have 10 plugged in before it starts to be a problem, and even pulling 20A to your socket (which is a common rating for mains sockets) still leaves plenty of leeway.
Until someone plugs their hairdryer or fryer in to the last one, which is possible because it is still valid socket.
You wouldn't (in the UK anyway) be able to sell these if they were rated less than the socket.
You would be doing something that seems safe, that will not trip the breaker but that will cause a problem. Just the fact that you can gang a bunch of stuff that is rated does not mean that there aren't any hidden variables here, and contact resistance is exactly that. Very easy to overlook.
That's why 'three way' connectors were outlawed in many countries (but not in all):
http://www.rapidonline.com/1/1/8248-3-way-mains-adaptor.html
That's the UK version, there are others for different places.
The euro-plug variety of them has been outlawed for so long that I can't even find an image of one.
People would get up to all kinds of creative uses for these, such as 'wonder why I can't plug on three-way in to another', and if that works why not several.
They're also known as 'firestarters', any idea why ;)?
If all of the mini-sockets are low rated there is no danger, because of how the socket is set up, if you use the other socket for something with a big draw (i.e. if you have a dual socket and plug one of these into it next to something with a big load it will not overload it).
If you overload this device or the socket it will trip the circuit breaker. Same as if you plug all the devices into different sockets on the main.
Heat is unlikely to be an issue, even with contact resistance it is related to the device it is powering - and I contend that this is not a plug you would use, rate, recommend or legally allow for high power devices. If you're powering three laptops it works out to about 1W for the whole device (rember, while the cable goes to each socket the pins are part of the device circuit, the parallel branch, not the main series).
The FAQs on his site claims it will be released this year: http://www.madeinmind.co.uk/faq.php - I sure hope so.
Min-Kyu Choi impressed every passer by with
his neat, apparently market-ready plug that
folds down to the width of an Apple MacBook Air.
http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#Type...
+ http://news.ycombinator.com/item?id=841068
+ http://news.ycombinator.com/item?id=927714 <- This one has some comments worth reading.
It was posted on Reddit a few years ago. It's been posted on HN twice already, it's gone around twitter.
Are you all new to the internet?
"The continent" is normally - in English - a shortened form of "continental Europe". Are you saying that you moved from somewhere east of the Urals or perhaps Turkey (if you don't believe that that's culturally European, although the part west of the Bosphorus is indeed part of the continent).
And adaptors are pretty pricy for things with no active parts.
Seems like a huge undertaking to me.
In America we have more than one standard we live with every day - two-prong plugs, 3-prong plugs, 220-volt plugs vs 110. You hardly every even think about it, except when you're shuffling through the pantry drawer, looking for an adapter.
There's IEC 60906-1, but I don't think any country ever adopted that.
It's much easier to unify currencies than to change every existing socket. As most adapters solve most of the problems, and it's easy to manufacture country-specific devices, this isn't really a big deal in my opinion.
Yeah, I was quite surprised that this is now a de facto standard, as most of my previous European travel took me to locations where another system was used (e.g. Italy, UK, Ireland).
I don't think that Europlugs are more solid, durable or safer than British plugs either. Comparitively speaking, they're flimsy, unfused, unearthed and the wall sockets can't be made to close up without a plug inserted.
The only "euro" plug (CEE 7/16) only handles 230V/2.5A, it was made to be compatible with every continental europe wallsocket (and low-power Class II appliances), not to work with big appliances.
The second most compatible european plug is probably the CEE 7/7[0] (Type E/F Hybrid), which combines the german "Schuko" plug and the french Type E, the Type F being widely used across continental europe, and the Type E adding a few more countries to the mix.
Past that, Switzerland, the Danemark and Italy have their own plugs (though according to Wikipedia, the Type E is now allowed in Danemark).
[0] http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#Type...
the female plugs in the adapter are not to spec to female outlet plugs. so it can't be legally sold there. (me thinks. in Brazil you can't sell outlet stuff that are not up to government spec)
no matter how well it fits or looks. Unless he managed to implement the shutter activated by the earth plug and minimum depths for the live contacts in that little box. Then i would be honestly impressed.
the female plugs in the adapter are not to spec to female
outlet plugs. so it can't be legally sold there. (me thinks.
in Brazil you can't sell outlet stuff that are not up to
government spec)