3rd Feb, 2005

Rethinking Power Plugs

Have you ever wondered why power plugs have the shape they do? The common American Type A design dates back to the original 1920’s two-pin plug design. Why are we still using 1920’s technology to power electric devices when virtually every other household technology has experienced rapid change and evolution?

It turns out that everything about electric wiring is strictly controlled by the National Electric Code, a national standard that is reissued every three years or so, but has changed so little, that aside from various safety devices, my dad’s 1960’s code book is virtually the same as his new one. Many, perhaps most, electricians are content with the standard 120V/60Hz/15amp 3-prong socket, but I would beg to differ.

First, the 3-prong, triangular plug is unnecessarily large. Using a flat plug design with two circular prongs and a ground in a groove would shrink the size of power plugs to a tiny fraction of their current size. (For somewhat superior standards, check out the European B, C, or SE plugs.) Second, the 120V/15amp current is either too strong or too weak for the majority of consumer devices. Most households use three types of devices: a few power-hungry home appliances such as dishwashers, vacuums, air conditioners, and disposal systems that need 240volts, medium to low power devices such as computers, speakers, and TV’s, and many very low power consumer electronics such as CD players, cameras, and computer accessories that only need 6-12V and 1 amp. The 120V standard is too weak for the large devices (your vacuum cleaner is limited to 12amps, for example) and is too much for small devices, which require a large transformer to use the power.

I am neither an electrician nor an economist, but I think it is likely that the enforcement of a national electric code has prevented innovation in this area. In developing nations, it is common for a single building to have multiple power sources with differing voltages, and plugs that support several different standards. Certainly, an electric code has many benefits in such cases, but when governments get involved in the construction code business in the interests of “safety,” the consequence is often technological stagnation. The case is aggravated by the fact that the code covers the United States and Canada, and thus prevents interstate differences which could introduce competitive differences.

Faced with a regulatory barrier on the construction side, entrepreneurs have introduced some innovations on the consumer electronics side during the computer revolution. A standard set of voltages has evolved for low-power devices, so that most transformers are interchangeable, and there are kits with universal adapters for devices in the 6-12V range. The creation of a power standard from an auto cigarette lighter is another example.
A recent development has been the proliferation of Universal Serial Bus (USB)-powered devices, despite the fact that a USB port is limited to 5V and 500mAmps. I own a USB-powered mouse, keyboard, camera, joystick, webcam, and an auto-USB adapter, and there are USB powered coffee mugs, lights, hard drives, nail buffers, Christmas lights and trees, disco balls, aquariums, and god knows what other kinds of devices. In effect, USB has become a de-facto global standard data and power standard that has overcome regional electrical regulations. There are over 1 billion USB devices in the world, and that number is sure to grow.

Nevertheless, leaving the evolution of electric wiring codes up to the market is likely to create power standards we can only dream of today. Imagine having a dozen tiny, flat plugs on every wall socket that power everything from a vacuum to your desk lamp to your keyboard and contain in-wall power cables that can be pulled out to connect to any device. Because these devices could transfer data as well as power, each plugged in device would register its power requirements and capabilities on the home computer, which could then remotely control them and manage overall household power usage. A printer, webcam, or TV would be connected in the living room and network with a computer over the power line. Bulky transformers and separate power cords would be history, and electronic devices would shrink because external power sources would automatically adjust to their needs. All the components for this technology exist today – but attempting to integrate and mass produce them in households would be a legal and regulatory nightmare.

Responses

In alternating current, the higher the voltage, the lower the losses in wiring (contrary to DC). Electricity is transported at very high voltages across the country. As it is distributed it goes trough numerous transformators to arrive at your home at 120V in USA and 220V in Europe. Distributing electricity at low voltage to your house would mean too much loss. Actually the bulky transformers are a good idea.

A friend of mine has just built a new house. There is not a single traditinal light switch. Everything is done by domitica. His light switches just tell the computer to switch on the light. At night when he suspects a burglary, he can switch on any light in the house from his bedroom, BEFORE he goes down and has a look. I my opinion there will be no need to review electrical code, except to have a same code troughout the world. Real progress will be made by domitics. Current will come to you house as it does now. The house will be equiped with traditional sockets and USB type sockets or other. The USB sockets will deliver power to low-tension appliences and exchange information. Why settle with innovative electricity if you can have automatisation?

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As evidence to my praise of the USB standard, check out this article on the development [...]

This is about the dumbest thing i’ve ever read.

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