Digital Power Unleashed

Would they do it?

If CE product vendors could wave a magic wand to eliminate the need for an external power adapter for so many of their products, would they do it?  If there were a way for notebook PCs, cordless phones, printers, digital picture frames, wireless routers and other products to get power without the need of an AC-DC power adapter, would the product vendors benefit?

Like the Myth Busters, we'd like to get to the bottom of the myth that product vendors want power to be non-interoperable.  We'd like to hear from you about your thoughts on whether vendors enjoy benefit from or suffer unnecessary costs because of the lack of interoperable DC power solutions.

That last iPod I bought is compelling evidence to me that vendors benefit from universal power; the iPod doesn't come with a power adapter.  If you want one, you have to pay extra for it.  This is good both for vendors and consumers, because USB power is commonplace.  I didn't buy a power adapter for my iPod; I already had 3 or 4 USB power adapters that work with my iPod and many other USB-powered products.  But Apple didn't have to give me one at its expense, either.

We invite product vendors to comment on the net gain or loss they have due to the fact that today, there are no interoperable power interfaces for non-USB-powered devices.

There is a magic wand that we can wave to fix the problem.  But, it will take a few years for it to be waved completely.  We can get to a place where power is universal and smart power outlets are commonplace.  The cost to enable devices to accept power from smart power outlets is negligible in comparison to the costs reduced in dealing with product-specific power adapters.

One challenge for product vendors is that the savings from the elimination of the product-specific power adapter happens later, even though small costs are incurred immediately.  I've reviewed several economic models that all show the payback is significant and substantial, even accounting for the mismatch in timeline.

All viewpoints are welcome.

Fig. 1:  Embedded costs of power adapters.

There Are AC Power Strips; Why Aren't There DC Power Strips?

Today, I looked under the desk in my den and I saw two AC power strips and one UPS with multiple AC power outlets.  Then, I noticed that only two devices in my office did not have an external AC-DC adapter - my desk lamp and the UPS itself.  But, 11 power bricks and wall-warts - each capable of powering just one device - are plugged into the many AC power outlets supplied by the AC power strips and UPS.

Something is very strange about all this.  I have had the AC power strips for years and years.  But the power bricks and wall-warts come and go so frequently.  How many cell phones, laptop PCs, printers and cordless phones have I had over my 20-year career?  Could it be that my AC power strips have been faithfully serving me for so long?  And, if so, why is DC power so different?

Two things are obvious to me about the role of AC power strips:

1. One device serves multiple products
2. Any device can get power from any AC power outlet.

AC power is interoperable, because (at least on a country-wide basis) it has a fixed voltage.  Our DC-powered products, however, use 5V, 6.5V, 7.5V, 9V, 10.5V, 12V, 14.4V, 16V, 18V, 19V, 21V and other voltages.  They're all different.  Attempts to standard on voltages have failed, because different products optimally work with different voltages. 

One way to deal with the many different voltages that DC-powered products require is to enable power supplies to negotiate the necessary voltage and current levels with the DC-powered products.  Green Plug developed a power communication model that enables any powered device to dynamically negotiate power with the power adapter it is plugged into.

Once the communication link has been made, an unlimited number of power monitoring and control applications are possible.  For example, power adapters can dynamically adjust their output to adapt to changing conditions such as being powered off or having reached full battery charge.  Also, a single AC-DC power adapter can serve power to multiple DC powered devices.

So, instead of throwing away 200+ DC power bricks and wall-warts like I have these past 20 years, I could have used just 2 or 3 multi-port DC power hubs.  Product vendors would not have had to bear the cost of designing, packaging, shipping and giving me the power adapters with the products I purchased.  My wife and I would have had less clutter in our den.  And, the environment would be much better off.

Isn't it time for DC power strips that can dynamically adapt to the power needs of anything that plugs into it?