FROM EDN EUROPE: Making the right connection

The other day, my e-mail inbox contained a message promoting the products of Mobilewise Inc (www.mobilewise.com), a fabless-semiconductor company. The pitch promised "wireless power" for my portable electronic devices. I was intrigued; had someone realised the science-fiction dream of power transmitted through the ether? (Flash Gordon! Lock us onto the power beams!) Or was I being offered the chance to sit in front of a cut-down electric-induction cooking hob as I work at my laptop? Digging through the hype, I found that the reality was rather more prosaic but nonetheless ingenious.

The Mobilewise chip set allows the company to build a power-connection and -recharging system for portable products that uses a desktop pad containing a matrix of connecting points. You build a pair of matching contacts into the underside of your portable device, then lay the device anywhere on the pad to connect to power. Reading somewhat between the lines of the company's presentation, I gathered that both devices in the client/host relationship start in a high-impedance state. The host (pad) scans for a conducting path between any two of its connecting points, and when it finds one, it offers a few volts from a high-impedance source. It then asks whether the device is compatible and how many volts it would like. If the host indeed finds a client device, a handshake occurs, and both devices can open a low-impedance path to supply power.

As I read further, however, I began to wonder whether the promotion was actually focussing on the product's best angle. When all is said and done, the desktop pad is just a clever connector. What does it offer that I can't get from a 10-cent conventional connector? Certainly, it eliminates one trailing wire per device on my desktop (in the chaos of this desk, that's not much of a concern), but for some devices, it actually eliminates a degree of freedom. If I have completely exhausted my cell-phone battery, I can use it again the moment I connect its charging cable. But I can't use a phone that's sitting on a desk pad, sucking power.

Focussing on the matrix pad obscures the product's real potential contribution. I'm not much concerned about plugging in my portable devices to recharge them; we have all grown used to that system, and even if the desk-pad idea does take off, we'll still need that recharging system as soon as we move away from our desks. The greater problem, I believe, is the proliferation of charger types, voltage levels, and connector types. Today, they are all essentially dedicated devices. Each laptop, cell phone, PDA, or other device, has its own unique charger. The saving grace is that, with the widespread use of universal offline input circuits, they all work pretty much anywhere in the world (if you remember to pack your mains-adapter kit). Some degree of universality—a standard "portable device-recharge connector," so I don't have to worry about carrying the right charger for every device—would be a real step forward. Mobilewise appears to have taken that step, if it has indeed implemented an autonegotiation protocol for supplying charging power, but its promotion hardly mentions that aspect, concentrating instead on the "wireless" connector.

I don't claim to be an authority on what average users want from the power connection to their portable equipment, and I'm sure that Mobilewise's marketing and research has told it which features to emphasize. But my take on the product's real contribution reminded me of peoples' tendency to become fixated on their own great ideas. Have you ever worked on a project that incorporated a favourite idea of your own, that you nurtured and concentrated on so that it developed just right? Were you entirely rational in dividing your time between your idea and the rest of the project? When you are arguing for resources, allocating your time, or choosing the features to promote, it's easy to obsess over the aspect of the project that represents your own special idea. Sometimes, we need to force a measure of objectivity on ourselves.

In the meantime, as soon as someone builds that universal, autonegotiating battery charger, and defines a universal connector standard to go with it, I want one!

Contact me at gprophet@reedbusiness.com.