One Plug. One Planet.

Get Ready for a Power Revolution

We couldn't be more pleased to see the progress being made in the efforts towards wireless power as described in the "Wired" article: http://www.wired.com/gadgetlab/2009/02/wireless-charge.

Green Plug promotes the benefits of a new power model that include:

• Reducing power cord clutter since each power supply can power multiple devices concurrently
• Reducing standby power drain, which can be significant when you replace 4 or 8 individual power adapters with a single smart power hub
• Providing unprecedented convenience - never worry about finding the right charger for a specific device or about forgetting your laptop charger (anyone will work when devices can negotiate power with power sources)
• Reducing toxic waste caused by the disposal of billions of device-specific power adapters (interoperability means power adapters will be used again and again.)

Wireless power solutions hold the potential for even further reductions in power cord clutter.  But powerful, efficient solutions may still be off in the future for laptops, televisions, printers and similar products.  We can take a major step towards the wireless power solution today by making consumer electronic products able to accept power from any power source whether it be wireless or wired.  That way, power hubs can be developed that offer both wired and wireless power ports.

It is unlikely that every home and office electronic device will be equipped to receive wireless power.  But, just as many wireless routers also integrate wired (Ethernet) connections, we think that a wireless power mat with a few integrated universal wired power connectors provides the ultimate in convenience and interoperability.

We'd like to hear from you.  Please share your thoughts on this topic.

The Digital Power Wave

Hello:

This month's blog is brief, containing a link to an event on trends towards the use of digital power controllers.  Please take a look at: http://digitalpower.darnell.com.

Last month, our CTO blogged about innovations in the power supply industry due to the use of digital controllers.  At DPF '09, you'll learn about techniques for adaptive control and learning systems.  At Green Plug, we're happy to see smart power supplies gaining momentum, with an estimated 5 billion units shipped by 2010. 

Digitally controlled power adapters have all the necessary components to support the open systems power interface that Green Plug advocates.  The availability of these smart power adapters will make it possible for vendors to provide dynamic output power configuration and build new power monitoring applications without adding hardware costs and will enable vendors to provide the kind of interoperability that consumers crave.

Digital control circuits for power supplies are coming

   By Gus Pabon, CTO

    Since about 1973, power supply controllers have been analog and not much has changed in their basic functionality, until recently.  An emerging trend is happening where digital power supply control IC’s are starting to make their way into designs and they show a huge potential for additional benefits that can be brought to power conversion electronics.

    In today’s analog technology one approach for regulation and control of the output DC-voltage is achieved using a voltage-feedback method that compares the DC-output voltage that is proportional to a reference voltage that is part of this feedback loop; in this part of the electronics, additional circuitry is used to compensate for amplifier gains over adequate frequency ranges to ensure stability of the output voltage.   The difference between these two voltages is then used to set the limit when compared to a voltage ramp generated internally by the control IC;  this difference-voltage and the voltage ramp are inputs to a comparator circuit whose output results in a square-wave of voltage with a varying duty-cycle.  This duty-cycle-varying square wave drives the power switches in the power supply.  By this method, regulation of the constant DC-output voltage is achieved even under conditions where the power supply loading changes.

    Now, with the emergence of high-speed digital electronics, this feedback-loop can be implemented in a digital form.  The output voltage can be fed to an Analog-to-Digital (A/D) converter whose output is compared in digital (multi-bit) form to a digital-reference.   The difference is then fed in its digital form to some type of Digital-Signal-Processor (DSP) as part of the digital-control circuitry.  This DSP , among its many functions, performs compensation to ensure stability of the feedback loop and hence the output voltage.   The output of this DSP is then fed to Duty-cycle registers that output (as in the old analog-control method) a square-wave of voltage with a varying duty-cycle that is used to drive the power-switches in the power supply.

    If the basic functionality described above was all that was required in the operation of a switch-mode power supply, digital-control would be at best equal to the mature analog solutions.    It is in the digital circuit’s ability to dynamically change its operating mode where a digital controller shines and outperforms an analog controller.   A simple example considers the stability of the feedback loop over a wide operating range of the power supply’s output current; each current load of the power supply determines an operating point.   In the analog method, the feedback loop is optimized (compensated) for stability for only a few discrete operating points and outside of these operating points there still exists stability, but the operation of the feedback loop is not at its optimum point.  The reason for this is that the stability of the feedback loop in an analog system is achieved by using discrete-components (capacitors, resistors) that set the frequency-dependent gain of an amplifier.   As these components are fixed in their values, the compensation and hence the performance of the feedback loop is fixed.

    In a digital system, simple monitoring of aspects of the power supply’s operation (such as output current loading) can be fed to the digital-controller and the digital-controller can employ firmware that can digitally change the compensation depending virtually on any operating point of the power supply and ensure close-to-optimum operation of the feedback loop.  This is possible because only firmware and not discrete circuit-components determine the compensation of the feedback loop.

    Other clear benefits of digital control are that accurate and reliable communication is enabled with a digital-controller.  Such communication with the “external” world can be bi-directional.   This communication enables the power supply to be configured from an external source by receiving communication or by the power supply sending information, enabling a single power supply to be used for many applications – to achieve universal, interoperable behavior.   Communication also enables monitoring of the power delivered by the power supply or the “state-of-health” of the power supply and its components, and is readily available to any host system chartered with overseeing the power system.

    Also, every power supply has additional “house-keeping” circuitry whose function is usually for protection and prevention of catastrophic failures;   this is additional analog circuitry that adds cost, requires pcb real-estate both of which are not desirable and also as the protection-thresholds are set using discrete circuit components they are not easily modified.   In a digital-controller, much of this protection function can be done in firmware thereby eliminating additional circuitry and as describe above the protection-thresholds can be easily and dynamically (on the fly) changed in firmware.

    Today digital-controllers are two to three times the cost of their analog counter parts, but as our demands for power-converters increase as is happening due to trends in rechargeable battery systems, solar-arrays, electric cars, etc.,  so will the complexity in their designs.  This increasing complexity in applications will soon be hard-pressed to be met by analog controllers.   When this point of inflection is reached, higher volumes of digital-controllers will drastically drive the prices down, resulting in cost-competitive solutions.   The trend toward digital control in power conversion is only in its infancy and the potential of the benefits it brings to a power electronics designer are sure to be welcomed as a breath of fresh air.

The significance of the GSMA announcement

I read a very interesting article (http://www.popsci.com/gear-amp-gadgets/article/2009-03/universal-phone-charger-so-what-0#comment-33540) on the significance of the GSMA decision to adopt USB power for cell phone devices.  The major benefit comes not from the standardization on the cell phone-side power connector, but on the choice to require a USB power adapter with a USB-A connector.

Because the USB power adapter has a universal connector, you can use just one power adapter to power a variety of products, simply by changing the cable.  For example, I use my iPhone power adapter (designed by our CTO) to power my iPhone, Bluetooth headset and digital camera.  When I get a new phone, Bluetooth headset or digital camera, I won't need or want a new power adapter.  USB power adapters will be commonplace and we won't throw them away when we buy new 5V products.

The hard problem is to provide the same level of interoperability to non-5V products.  What's needed is a means of dynamically configuring the power adapter output to match the power needed by any device connected to it.  When we do this, we will significantly reduce eWaste from unnecessary power adapters that get thrown away simply because they are designed to work with just one product.  Consumers will enjoy the interoperability.  The environment will be spared a signficant waste.  Vendors will not be required to give away power adapters that work with just one product.  Everyone wins.

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?

On Helping Raise Awareness for Universal Power

The responses to our thoughts on GSMA's recent news, and on bringing the world closer to a universal power standard, have been outstanding. Two recent examples are Gadgetell's post written by Heather Wood, and The Industry Standard's writeup, by Lincoln Spector. Thanks to them, and to the many others who are helping bring this issue to the forefront. 

In order to address some of the questions that have surfaced, I present my thoughts (originally pulished as a comment on the previously-mentioned Gadgetell post):

While the GSMA is standardizing both the power adapter connector and the cell phone device connector, Green Plug has taken an approach similar to what China mandated as law.

To sell a cell phone in China, that phone must get power from a power adapter that has a USB-A connector.  So phones can use whatever connector they want and still be able to interoperate with any standard USB power adapter.  All that needs to be device-specific is the power cord.

When you consider the vast number of device types, shapes and sizes (Bluetooth headsets, notebook PCs, digital picture frames, portable game controllers, etc.) we agree that it can take a while to standardize on the device connector.  That’s why Green Plug does not mandate a universal device connector, but does require the power adapter to use its innovative power adapter connector.

It’s innovative, because we license it free of charge and it accepts any standard USB-A plug. It also has extra power pins to enable it to power devices up to 180W each with a single power port - many times more power than USB provides for.

The Alliance for Universal Power Supplies will encourage the development of a universal device power connector. But, as you point out, that may take a while.  Getting the world to standardize on a reusable, convenient and interoperable power connector on the power adapter side, however, should not be difficult. That is why China took their approach, and Green Plug also focused on standardizing the power adapter side first.

Thank you again for helping make the world aware of how important it is to eliminate the unnecessary disposal of power adapters that are in perfect working condition, simply because they are incompatible with other products. This costs manufacturers money, consumers hate it, and it is bad for the environment.  

The change is simple.

Our thanks also go out to all of you, like MacsiumusNews,  The greeen frog from silicon valley,  and ZDNet's Heather Clancy who are helping to spread the word about I Want My Green Plug. Every vote counts.

Can You Feel the Tipping Point?

Have you ever wondered if you can actually feel the tipping point? That point in time when the momentum of a game-changing event has built up enough inertia to move a market?  Today, the GSMA at the GSMA Mobile World Congress in Barcelona made an announcement that feels a lot like a tipping point.

Green Plug has long advocated the need for an open systems power interface to enable interoperability, reuse and to reduce  unnecessary parts like device-specific power adapters.  In a world with universal power, vendors save money, consumers have greater convenience,and harm to the environment is significantly reduced. 

Does anyone lose?  We don't think so.  In fact, the model that Green Plug advocates provides the platform for innovation in power monitoring and control applications.

What is significant about today's GSMA announcement is the fact that it validates the need for reusable, interchangeable power solutions for cell phones. This is relatively easy to do, since cell phones are all fixed 5V devices with little need to negotiate power requirements. But what about all those 6.5V, 9V, 12V, 14.4V, 16V, 19V, 21V and other notebook PCs, cordless phones, printers, game controllers, power tools, rechargeable toys, portable DVD players, digital picture frames, wireless routers, etc.?  How is a universal power source supposed to know how to dynamically negotiate the exact power requirements for each device connected to it?  That's where Green Plug's solution comes into play.  By default, Green Plug-enabled power adapters will power all the GSMA phones as well as just about any other electronic device.

China and Europe have validated that everyone wins when we have universal power.  Please help us send a strong message to consumer electronic manufacturers, and help make this a reality both in the US, and globally.

As always, we thank you.

Paul Panepinto is Executive Vice President of Sales and Marketing for Green Plug. His will be a leading voice in this blog. You can email Paul, here.

Passionate About Universal Power? Yes, We Are

And it seems we're not alone. Thanks to Slashdot we've received over 2,000 new votes on I Want My Green Plug in under 24 hours, and hundreds of new supportive comments.  Some excellent points have been raised in the Slashdot comments, and we hope to address many of them, here, since due to a technical glitch we were unable to post on Slashdot.

On USB As a Universal Standard

USB is indeed a universal standard. It does not require voltage negotiation, since the voltage level is fixed at 5V. By default, Green Plug-enabled power hubs provide power to USB-powered devices. Green Plug also enables any load (electronic product) to safely accept power from any power source. 

E-Waste Can Be Drastically Reduced

Why is it that each electronic product must include a device-specific power adapter, resulting in billions of them being discarded as e-waste? It's because they all require unique voltages and have different maximum current levels. Ideally, homes and offices would have multi-port power hubs that dynamically adjust to the needs of electronic products connected to them. This would eliminate the need for product vendors to have to produce disposable, device-specific power adapters for each product shipped. 

Green Plug's Method 

There are several power adapters today that configure output voltage to the exact voltage needed by connected devices. Green Plug's method is unique in that the power negotiation is based upon digital communication. Not only can initial voltages be matched to connected devices, but smart power hubs can dynamically react to changing conditions. New monitoring and control applications are possible when there's two way communication between powered devices and their power sources. Green Plug's interactive communication model enables standby power shutoff and dynamic reconfiguration of output power based upon changing state of powered devices. 

Greentalk: Will It Become a Standard?

Someday, Green Plug's Greentalk protocol may become a standard. A non-profit industry consortium, the Alliance for Universal Power Supplies  has been set up to bring manufacturers and other stakeholders together to drive, develop and promote standards for the power supply and electronics products industry. Green Plug has only just begun working with major CE device manufacturers that all recognize that the existing one-to-one power model is broken. It costs manufacturers a lot of money to include power adapters in their products; consumers hate them (who doesn't have a drawer full?); and they are normally thrown away when they are in perfect working order. That's not sustainable and there is a better way. 

Our Progress

Green Plug is making terrific progress in its discussions with the most popular vendors. Decisions that affect hundreds of millions or billions of product units are not made quickly. Our first customer demonstrated an award-winning power adapter at CES, where we showcased several concept systems at CES that showed interoperable power. We've also begun working with influential organizations that see the potential for the new open systems power model. 

Licensing Process

Greentalk is licensed free of charge to qualified manufacturers of load devices (electronic products that consume power.) On the load device, Greentalk can run in an existing processor and in some cases can be implemented for no added cost. Even in devices that require hardware modifications to run Greentalk, the cost of implementing it in the load is a tiny fraction of the cost of an external power adapter. Even legacy devices can get power from a Green Plug-enabled power hub through a smart cable. If we could get beyond the chicken-and-egg scenario and imagine that smart power hubs are ubiquitous, product vendors could eliminate the cost of building, packaging and shipping external power adapters with their products. Everyone wins. 

What's Ahead

You can expect to see some announcements this year of major electronic product vendors incorporating the free Greentalk protocol into their products. We hope you will continue to support our mission by voting to encourage more manufacturers to adopt this technology. 

As always, we thank you for your ongoing support.

3,500 New Votes on Iwantmygreenplug.com over the 2/6-2/8 Weekend

We were delighted to see over 3,500 new votes on iwantmygreenplug.com and hundreds of new well-written supportive comments, thanks to a posting on Slashdot.  We tried to respond to the posting on Slashdot, but the page is filled with javascript errors and won't publish our comment.  Anyone know if there's a workaround for this problem?

There were approximately 4,500 votes on the iwantmygreenplug.com on Friday, February 6th and as of right now there are 8,061 votes.  For everyone who's voted thank you for your support!

Unfortunately our web server was not set-up to handle such a huge influx of traffic and we sincerely apologize to anyone who experienced a site that was slow to respond or otherwise couldn't vote on www.iwantmygreenplug.com We are moving the site to a server that can handle many more simultaneous connections and you will find that the site is much quicker to respond within a week.  Please do keep telling your friends and family to vote on www.iwantmygreenplug.com just ask them to be patient while we complete this server migration.

Here are my top 10 favorite comments from over the weekend (in no particuclar order). 

1. "This is not only green - it is also the only clever way. Manufacturers not supporting are demonstrating lack of both customer and environment focus...".

2. "That's a great idea indeed. Battery operated devices are supposed to help one with mobility. But the variety of their chargers and/or adapter bricks is just hindering it ! Good luck with your project !".

3. "Having a universal power adapter has been far too long in coming. Having a multitude of different power adapters is an expensive and wasteful for the end user. I am tired of having to carry a pile of power adapters every time I go on a trip. And there have been several times that I’ve had to spend $30+ for a missing/broken adapter simply because of it having a proprietary connector and/or power requirement."

4. "Ever try finding the adapter to rogue electronics at 3 in the morning?"

5. "I want this as a standard! I will not by another device until this is available. I have tossed hundreds of dollars into my junk basket due to dead power adapters and/or devices ruined by inadvertent mismatched power adapters."

6. "I have a closet full of chargers. Worse, they're the cheap, inefficient type. We need a universal, efficient power supply to help save electricitry and $$$. One plug (even if it's expensive) would be a great solution. Manufacturers wouldn't have to include it in their product, lowering the price of electronics."

7. "I dream of not worrying about which charger I bring with me when I travel."

8. "Just like the late Douglas Adams said in his writings entitled 'Little Dongly Things', there is no need to have so many adapters! It is *not* consumer friendly at all! Traveling and mobility, in essence what the majority of these devices are for, becomes infinitely more cumbersome, let alone even having an appropriate number of wall outlets to handle these plugs. And none of that even addresses the environmental impact of the existing design. Simply put, the current way of powering things is flawed. The older design is flawed. There needs to be a change. I believe GreenPlug represents that change (...and I also wish that last statement didn't sound so much like a political speech! [lol])"

9. "Consumers should not be held hostage by those that produce the equipment we all use. Choosing components with interchangeable parts has been and will be a criteria when deciding on technology purchases for me and my company."

10. "I'd like not to need to keep around a box of power supplies just in case."

You can see the rest at iwantmygreenplug.com/comments.php

Thanks again for all your votes and comments!