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, a 1960′s code book is virtually the same as a 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.