Westinghouse Commits to Green Plug's Universal A.C. Adapter

Ian Lamont writes "Westinghouse is the first major electronics manufacturer that has publicly committed to using a 'smart power technology' that will let people use a single universal adapter to power their laptops, cell phones and other electronics. The universal adapters, which use a technology developed by a startup called Green Plug, will act like a hub that several devices can plug into, and will also shut off the power supply when the device is turned off or has finished charging. The first are expected to go on sale in early 2009 for under $100, according to Westinghouse's CTO. Eventually, Westinghouse and other manufacturers that use the technology could stop shipping adapters with their products, because customers may already have universal adapters at home. However, some manufacturers may not be inclined to use universal power adapters: the article notes Apple gets supplementary revenue from the sale of proprietary connectors for the iPod and other devices."

Comments

This is going nowhere.

[Ritz_Just_Ritz]

The cost to add the technology to a company's device is listed as US$2. The cost for a company to produce their own wall wart in China...probably less than US$2....and no licensing fees to worry about and no worries that the customer might not have a charger. This idea is going nowhere.

In this case, I think the Chinese government actually got it right. They've forced all cell phone manufacturers to provide a USB port for charging the phones. Seems like a reasonable standard to me.

Cheers,

Re:This is going nowhere.

[Hal_Porter]

Hal Porter said:
The computer will supply at least 5V 500mA to a device before it enumerates.
and got moderated Informative for it.

I don't know who did this moderating, but it must be someone who, like Hal Porter, does not know the USB spec.

A USB device may only draw 100 mA before it is enumerated.
When it is enumerated, it may negotiate more power with the driver, up to a maximum of 500 mA.
When it is connected via a USB-powered hub, the driver will decline this request, and current stays 100 mA max. I know what the spec says, I'm just pointing out that a PC won't enforce that 100mA limit for the excellent reason that loads of devices use USB just as a handy 5V supply and don't have the necessary smarts to enumerate.

If it did enforce it, people would return it as incompatible with this sort of device.

And that's really the point here. The spec isn't the whole story and most USB hosts were designed by people who wanted to maximize compatibility with devices that skirt the rules rather than robotically enforce "ze rules" and then tell users they were idiots for not understanding the spec. It's like something out of theoldnewthing really. The user doesn't know the spec, they just buy cheap USB gizmos. And cheap USB devices will most likely work like this because they don't need a microcontroller. Telling the user you won't support their device and they were an idiot for buying it is just being a jobsworth.

Otherwise, you could draw 2A from any USB port by simply connecting 4 devices through a hub. Ok that's a different case. A non powered hub may well limit downstream power, so USB hard drives won't work if you connect them to it. Or the PC will detect overcurrent and disable the port. Or you'll end running the host port way outside its max power rating. This is a place where it would be correct to enforce the rules because not doing so may actually destroy the host.

Enforcing the "100mA before enumeration" rule is silly though and that's why no USB host I have seen does it.