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A Universal Power Bus?
mjpalm21 asks: "A friend of mine recently sent me this story on a new universal power technology that charges devices through your desk. This is a cool idea, but it seems complex. I have long wondered why there isn't a universal power bus (UPB) along the lines of universal serial bus (USB). UPB would work like this: You would buy a n port UPB hub for your desk, and then all of your electronic devices (cell phone, PDA, computer speakers, modem, phone, hubs etc.) would plug into the hub via a standard UPB cable. I would think that the device manufacturers would be all over this as it would reduce their product cost (no need to bundle a power brick), reduce their packaging cost (smaller box), increase customer satisfaction (I know I would be happier), and give them another device to sell (the UPB hub and all those cables)! Why hasn't this happened yet and what would prevent it from happening?"
You can connect your devices using these universal cables.
Remember back to the 80s and how clunky things seemed to be? Most of that was due to the battery. Everyone used the same batteries to help bring down costs, but then the final design was around the battery.
Since formed batteries have dropped in price significantly, they can make nice sleek designs and work the battery in rather than the other way around.
Whats this have to do with your question? If everyone could use the same power source, it would mean all devices would be required to support N Volts at N Amps (or set internal resistance accordingly). This means the addition of a step up or down DC-DC transformer to all devices, and taking a step backwards on battery design as you must accommodate the lowest common demoninator again.
However, not all is lost. There is a slim possibility you could add a layer of communications with the block and request a specific voltage from it, thus placing the logistics into the power block.
Figure out how to do that in a small package, and it may simply become the AC outlet. Quite clunky to accomodate at the moment, so specific individual bricks rather than an über brick is far cheaper, smaller, and much less prone to failure.
For now, just be glad the brick isn't an integrated part of the device.
Rod Taylor
What he's asking for is a very sensible idea. Airlines have already picked up on the notion that providing a low voltage power source for laptops would be quite handy by removing the need for the power brick, and have helpfully come up with multiple standards . If you think that the idea of a standard low-voltage power source in the modern household--and especially around the computer--is so wayward, just look at the growing number of USB peripherals that are learning to make do with 500mA at 5V in order to live entirely off the USB bus.
In fact I think USB will turn out to be the motivator of a revolution in standardized low power busses, because manufacturers will get used very quickly to the ubiquitous availability of a power source for their TLL logic and stepper motors without having to worry about power supplies. This has never really been the case in the past, serial and parallel devices (almost) always requiring separate power sources.
The standard could be a lot simpler than what some are suggesting. A system could consist of an under-the-table brick that plugs into a wall outlet and contains a switching power supply, with a low-voltage power strip going up to the desktop. The connectors could be simple USB-plug-like affairs with pins for ground plus 12V and 5V, satisfying the vast majority of consumer electronics devices. The standard would specify what the maximum current draw could be at each voltage level, and device manufacturers would simply design their devices towards this standard. Almost everything around your computer except for the CRT and laser printer can run off 12V and a few amps.
Face it, the 110V power system was designed for exactly the same reasons, to provide convenient and standardized power to the devices in your household. Except that that was at a time when your average consumer electronics used tubes, ran its signals at dangerously high voltages, and also doubled as space heaters. In this growingly low-power world, 110V AC just isn't all that convenient anymore. So don't be surprised if the homes of the future will indeed sprout new wall sockets.