By Graham K. Rogers

Apple rumours have expanded greatly this week as the news about the Apple Event scheduled for 10 September spread. This soon became "events" with the addition of China; and then expanded to include Berlin and Tokyo, causing much excitement. What the next iPhone will be, is still open to speculation, despite what has appeared online. As well as the (sometimes misleading) stories, AppleInsider put out a rumour about a new charger being developed by Apple for a mystery device.

Late Wednesday night, after reading about the rumour that Apple was to produce a 17 Watt charger for some, as yet-unknown device - like Neil Hughes who wrote the AppleInsider article - I sat down with the products (and chargers) I had, to try and figure out what the mystery item could be.

With the current lineup of devices that Apple has, there is nothing that would appear to fit the bill: Macs need much more, iOS devices less power. The Airport Extreme Router is close at 25 Watts, but the power supply is now integral, so this would not seem a likely candidate: why un-design something that looks fine as it is?

Still wondering about what the charger might indicate for a new area, I went into my office. Luckily, I work at a department of Electrical Engineering, so was able to pick the brains of one of my colleagues. To make it easier - English teachers and Engineers do not always think along the same lines - I produced some diagrams to go with my thoughts.

Situation One: Normal

Situation Two: Low Power

Situation Three: Higher Power

Situation Four: Hypothetical

Older iPad and Airport Extreme Power Adapters

We could now group the devices: iOS devices taking lower power, with computers drawing more; and in the middle the routers at over 20 Watts. It was only then that I mentioned the rumoured 17 Watt power adapter. What could that be for?

My colleague thought for a moment and implied that I was barking up the wrong tree. It might be a device, of course, but you would also need more power, he told me, if the battery was to have a larger capacity. Increasing this - measured in terms of amp/hours - would require a higher power for charging.

It is well known that Apple has brought in a number of innovations for battery technology and seems to be deeply concerned in bang for the buck: making the device thinner, while at the same time increasing the hours that a charge will last for. One of the more interesting videos from Apple was produced for the introduction of the MacBook Pro 17" at MacWorld 2009 in which Bob Mansfield explains some of the technical and industrial processes that Apple had introduced for the new battery types. These were later used in all the devices.

While a 17 Watt power supply may suggest a new device, it could be that Apple has improved on the current technology and is managing to squeeze more out of the batteries that will be installed in devices that appear next year: perhaps as significant a development in itself as a new device.

Thanks

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand where he is also Assistant Dean. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs.