New power immed.-distrib. tech/std. conserves?

There are a number of problems with this have prevented this form of power distribution from ever being adopted. The important ones are - cost, flexibility, and international standards.

COST - The system would be more expensive than our current one. It would actually be hugely expensive to implement. It would waste more resources in infrastructure change both in the electronics and building industry (building design and codes would need to change, and quite a lot if you want distributed DC bus systems in buildings) than would be saved by staying with our current system. Copper prices are very high at the moment also.

FLEXIBILITY - It isn't flexible enough. In fact it is far less flexible than current methods. For home use, how many computers are you going to want in a room and what size power supplies will they require? Some houses may need none, some may need many. For business its even worse. To make it flexible you would need a lot of different systems, you would also need to take into account that technologies change (computers get bigger and need bigger power supplies, computer archetecture development dictates changing power supply voltages, etc). People dont want to have to upgrade their house when new technology comes along. These points also directly link back to cost. In the end you will still need many wall-wart adaptors for all those odd-ball power supplies and portable laptop computers. You would also need to keep the existing inbuilt computer power supply design as many consumers would still want the flexibility (and the infrastructure for building these is already there).

INTERNATIONAL STANDARDS - It's a big world, and there are many different voltages being used. These will change over time. Without a major world-wide rethink, this will always be a problem. Getting groups and countries to agree upon anything is difficult to say the least. The paperwork, redtape and politics alone will not make this project worthwhile. This is a nightmare of a field, trust me.

Development is continuing into more user-friendly wall outlet distribution systems (features such as recessed, cable-ways for data and telecommunication lines, flexible and safe entry points so that a plug can be placed anywhere along a strip, etc) but the output voltage is still the same 230V or 110V (or what ever local country voltage is used).

So in conclusion it won't work because it will cost more than what is done now, would be less flexible than what is being done now and would be a major headache. This is just too big a change. Perhaps some smaller scale development may be more suitable.

Hey, I have an idea - how about distributing a standard power - let's say 115VAC, through several outlets in each room of your house or office, and then build end-of-use converters to connect everything from computers to TVs to whatever, wherever you want them. And then as technology changes you just use the converter that comes with every new device. You could call them wall warts.

Now this proposal is more realistic (with some modifications of course). TV's and computers and similar such things which have special voltage needs already have special built-in power supplies. It is already a simple matter to get, say 5V with a very simple addition to that power supply, so a product you are suggesting is not going to be any help here. But, the promising area is in providing a simple mass-produced converter that can power devices that run on a single DC voltage, such as cellphone chargers, Halogen desk lamps, etc and be reused for another product. This would atleast help address some of the product waste that is created when a product is thrown away, by removing the bulk of the power supply out of the product and reusing it on the next.

But, how to start, hmmmmm . Manufacturers of new products could use a universal power supply for a large range of their existing and future product lines. This is already being done in the industry to a certain extent (as you mentioned with wall warts), but could be extended to cover a much larger range of products than just the individual product it came with. It may be possible to eventually reduce the huge number of variations between companies down to a few thru broard (but flexible) standardisation. It worked for batteries afterall.

I was just being facetious, of course. It's really a trade off of universality vs efficiency. You can get the most efficient power supplies if you design them to be optimal at a certain load, i.e., a particular device. You could gain some universality by designing a general purpose power supply to drive a variety of devices, but efficiency would suffer, especially if the power supply has to cover a very large range - say 1mW to 1KW.

Also there is the issue that many devices use multiple voltages : +12, +5, +3.3, +2.5, +1.5, +/-15 - these are all standards these days, and many devices require that these supplies power on in a specific order, and vary in the amounts of noise and regulation that are required. I can see a situation where your PC works fine until you plug in your TV, now there's too much noise on the power bus - because you've moved all the power conditioning circuitry out of the PC box.

Also, defining power standards would limit the design of new electronics. Example, if we chose the standard voltages widely in use 20 years ago, we would have +5V. But then it became necessary to go to 3.3V in ICs, then 2.5V, then 1.5V, and now we're approaching 1V. Whatever "standard" you build has to be able to change with the times.

The best power solution is a standard, and easily transformable single source (such as 115VAC, or the EU equivalent), and dedicated, high efficiency converters at the point of load in every device.

Most products that could benefit from a single separate reusable external power supply product will fall into a small power range and (to a lesser degree) voltage range. It wouldn't be too difficult to have a small range of selectable output voltages (say 2 or 3, likely no more) that could cover a much wider range of products, while still being cheap enough for mass production. Remember you can never cover all contingencies, but if you can cover many or even a few then there may be a market (especially in a huge market such as consumer products).

Yes, it is a complex problem. But a lot of energy (thus, natural gas, coal) is getting wasted. Your average computer power supply runs at 75% efficiency? That adds up officewide, nationwide. Pick all the nits you want, you're the engineers! Come up with more efficient power supplies. --PRC, Belmont, CA

Anyone who builds a supply with < 90% efficiency these days just isn't trying.

I hate these wall warts too, and would prefer that they simply be built into the device to be powered, as they are in desktop computers, TV's, stereos , etc. At least since the advent of solid state stuff, we've always had to provide one or more dc voltages to make things work. Why are these power supplies now outside the device, instead of inside?

In terms of energy consumption, I'd think the idle current must be extremely small: I might have 15 or 20 these things in my house, and I'd bet all of them combined consume a watt or two when idle. They'd be more efficient if they sensed load current and put themselves in standby mode (drawing a milliwatt or so) when off load.

It could be argued that all these wall warts are optimally sized for their intended uses, and that any standardized system would have to be built for a great deal of excess capacity, so that total efficiency would be lower.

I'd love to see outlets like you describe, but I can't imagine that actually happening. Other niceties would be one or two UPS sockets in every room, all supplied by one UPS located at the circuit breaker panel. Also, as I think you are suggesting, it would be great to have wire chases throughout the house, so that you could pull in additional wires when required without having to cut into walls.