Today in Tedium: I have a problem with electrical outlets, at least of the American three-pronged variety—every time I look at them, I see a face looking back at me, in shock at what I’m about to do next. The outlet looks like it’s seen some things. It’s fascinating to me that when they designed this power outlet style they looked at their options and the best they could come up with was constant shock. So, I know that power outlets differ in different countries, and more importantly, I know why. But what about power outlets that don’t follow any modern standards, or are so obscure that you might do a double-take when trying to figure out what they’re for? (If you live in an old house, you know what I mean.) Today’s Tedium, in an effort to give the poor shocked guy a break, dives into power outlet variants that run current outside of the norm. We do ten a lot, but just to change things up, let’s make it seven. — Ernie @ Tedium
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The year Philip F. Labre submitted a patent filing for a “grounding receptacle and plug,” the first example of a three-pronged power outlet, which is very similar to the modern design in North America, with the primary difference being the use of three flat blades, versus two. (This design flaw later led to a different shape for the ground, so the plug could only be put in one way.) Labre’s design, which fell out of patent status by the mid-1940s, became an official standard shortly after that, with some minor changes.
1. Socket plugs/Lampholder plugs
Where used: Anywhere with an outlet
When used: 1880s-1920s, still possible to use today
In many ways, before power outlets gained their modern use cases, the light socket, also known as the Edison screw, was the original plug, used for early electric devices like vacuums and fans. But what worked well for installing light bulbs wasn’t necessarily a good idea for plugging in external devices. We put light bulbs in different places than we do power outlets, which means that if we were to plug in a cable via a power socket it would be hanging up from the top or bottom of a lamp, and depending on how the lamp is placed, it could cause unnecessary bending on the socket.
It was a good design for light bulbs, but a bad one for just about everything else, which is why Harvey Hubbell designed something the plug, which, in its initial form, was something that screwed into a light socket and allowed less unwieldy plugs to connect to the electrical outlet instead. Call it the original dongle.
Eventually those dongles made their way into walls, but at least some of those light sockets appeared in fun places like floors and walls—something Kellscraft Studio, a used bookstore with a long digital history, has uncovered in its building.
You can still buy socket plugs today—Amazon sells them—but the days when you had to use them to get an electrical charge at all are long gone, fortunately. In many ways, the legacy of the light-outlet-as-socket lives on in the cigarette lighter socket, though that pushes direct current rather than alternating.
2. Concentric Power Outlets
Where Used: United States then, at sea now
When Used: 1880s-today (but in very niche cases)
Maybe you were wondering, like me, why traditional plugs don’t look like, I don’t know, RCA jacks. Like what made a power hack look like a multi-prong thang, and what made RCA jacks tend to be designed around single connectors wrapped in metal rings?
Well, wonder no more, as The Digital Museum of Plugs and Sockets, a site I’ll be referring to a few times in this issue, notes that RCA-style plugs like this did exist, and not only did they exist, but they predated the RCA use case by more than 40 years in their original form. (As the website notes, they were likely based on the jack plugs used by telephone switch operators, just as the headphone jacks we use were inspired by those same jack plugs.)
But beyond the fact that they existed and fell out of mainstream use is very surprising fact about these connectors: The unusual fact that these plugs actually found a use in maritime applications, something that would be a heck of a fascinating use case for something that was once seen as a bit player in the history of electrical sockets.
3. Duplex sockets
Where Used: United States
When Used: 1910s-1930s
Related to the rise of the socket plug is the tandem blade, the original format Harvey Hubbell designed when he first came up with the concept of replaceable plugs. Nearly two decades later, he came up with the more common parallel design, which Is still used today, and for a time, both designs were very common on the market. So how to solve for this? Easy, create a power outlet design that can accept both. There were two such types of designs in use during this period: First, a single one-slot outlet with parallel connectors, and if you rotated your plug, a tandem blade. Second, a two-slot setup closer to the standard outlet setup we see today, with a T-shape on either side. That allowed the outlets to take either format for years. In a patent filing from 1914, Hubbell described the setup as such:
Presumably the greater number of plugs now being manufactured have their knife blade contacts in what I will term the parallel relation, but there are hundreds of thousands of plugs in use having their knife blade contacts in what I will term the alined relation. It is, therefore, extremely desirable to provide a receptacle which shall be simple and economical in construction, efficient, safe, and durable and which shall be adapted to co-act equally well with either of the types of plugs referred to above.
The issue that led to this confusing state of affairs was a lack of standardization. It wasn’t until the 1920s that the National Electrical Manufacturers Association, the organization that helped to standardize the electrical outlet in the United States, came around—and they didn’t really do much of the way of standardization until the 1940s, so that meant some types of power outlets went into use in the U.S. in some kinds of homes … then disappeared when the standards started to emerge.
And that’s why weird half-solutions like the duplex socket existed.
4. Radio Outlets
Where Used: United States
When Used: 1920s-1940s
This unusual outlet type, which looks like a cubist’s take on a power socket, is actually designed to give radios of the era easy access to an antenna located, generally, in the attic of the house or possibly even outside. These plugs—which rely on a ground an an aerial connection—are so obscure these days that even electricians, who you would imagine have seen some things, often run into these outlets in total confusion, based on forum posts that have emerged over the years. The Plug Socket Museum noted that these outlets were often covered up by homeowners after the concept of antenna plugs fell into disuse.
By the way, if you had an extra need for additional antenna plugs for whatever reason, you could also get a duplex radio outlet, something that General Electric sold in its 1941 catalog.
5. Greek Tripoliki Power Outlets
Where Used: Greece
When Used: 1940s-1990s
The problem with not going with a standardized power outlet means that you’re going to be stuck dealing with a lot of legacy years after the fact.
And while the two-pin “Schuko” power outlet quickly became the dominant type of connector in most European countries, there were a handful of stragglers around the region that are largely compatible with one another.
One of a few outliers among international plugs is Greece’s three-pin power adapter, which was in use for much of the mid-20th century before being retired in favor of the dominant Schuko outlet. One point that the Digital Museum of Plugs and Sockets raises, which might be interesting to consider in retrospect, was the perceived compatibility of the Greek outlet with French outlets, as they explain here:
The striking similarity between tripoliki and old French plugs and sockets must have a reason. It is a tempting hypothesis that they have been introduced in Greece during electrification work by French companies. Note that the Greek words mpreza (socket) and fis (plug) are derived French words prise and fiche.
6. EmPower Connectors
Where Used: In the air over international waters
When Used: 1990s-2000s
These days, it’s common to find electrical outlets and USB ports that allow users to plug in laptops or other lightweight electronics on planes, especially on international flights. But before the smartphone era, it was kind of a rigamarole to get any sort of electrical charge in the air. That’s because of the existence of the EmPower port, a 15-volt DC port introduced in the 1990s and generally found on international flights. (They tended to be sold in duty-free stores, because of course.) These ports were essentially designed to let electronics plug in to stay powered on, but not charged.
This outlet gained a degree of novelty among tech enthusiasts thanks in part to Apple, which sold a specialized connector for it that supported MagSafe starting in 2006. The connector was confusing in part because of its added inclusion of a 20 mm port, which looks a lot like a car’s cigarette lighter port and as a result likely led to a lot of questions from curious customers about whether the device could be used with a car (short answer: not recommended, though you could probably get it to work).
These days, the DC EmPower ports have been replaced with AC outlets sold under the EmPower name.
7. Neutrik PowerCON
Where Used: Music venues, outdoor signage, workshops
When Used: 1990s-present
If we allowed plug standards to evolve beyond the NEMA standards in the U.S., what might the modern power outlet have looked like? One answer might look like the PowerCON.
The connector, relatively modern for a power outlet of sorts, is the work of Neutrik AG, a Liechtenstein-based connector firm first founded in 1975. (Yes, the famed microstate actually has has a decent amount of manufacturing happening within its borders.) The connector, which has gone through a few iterations over the years, is ruggedized, locks in place, and is designed to be used with specialized equipment that often gets used outside, along the lines of PA systems, lighting equipment, LCD screens, and other equipment where it’s more important that the connector be secure than standardized. (Of course, it comes with all the rubs that such an approach encourages, including a proprietary port, though Neutrik connectors can easily be found online not-too-expensively.)
While targeted at public settings like concerts, the adapter has found DIY interest as a modification for power tools that can be quickly disconnected and can utilize a single connector, easing cable management around products that can often be cumbersome to manage.
Ultimately, if we ever do get rid of NEMA standards, the future of power connectors, outside of the ones we already plug into phones, might look something like an ethernet jack for many electronics. Since 2003, the IEEE has supported the standardization of ethernet connections that pull through both power and data.
It’s already a common method for connecting surveillance cameras, and has some significant cost savings in certain use cases. For one thing, it can cut down on the number of cables you might have to put into a wall, while also powering electronics through the same port where the data goes. This concept has also been popularized at the consumer level thanks to USB, particularly the high-powered USB-C and Thunderbolt.
But one has to wonder whether the traditional plugs will ever die, despite the inconsistencies and risks they can introduce. To keep this at a high level, I didn’t even talk about the complexities of different voltages, and the headaches they can introduce across markets. If you’ve ever plugged into an international outlet using a weird international adapter, you know what I’m talking about.
That said, it’d be funny if tomorrow we dropped all our current outlets in favor of, like, these hook outlets that were once used in Germany before the middle of the 20th century.
Find this one an interesting read? Share it with a pal! And what’s the weirdest power outlet in your life? Share it with us and let us know why you’re still plugging laptops into light bulb sockets.