An Engineer in Wonderland – Charger power waste. Did they miss a trick?

nokia-power-consumption-star-chart.jpgSee all ‘Engineer In Wonderland’ posts

Call me fussy, but I do not like designs that throw away power.

Particularly designs that consume stand-by power.

High stand-by power, even if it is to save a few pence in manufacture, is sloppy design.

Some big players in the mobile phone industry:  LG Electronics, Motorola, Nokia, Samsung and Sony Ericsson recently got together to come up with a star rating for charger standby consumption.

The ratings are:

* * * * *     = 30mW
* * * *     > 30 to 150mW
* * *     > 150 to 250mW
* *     > 250 to 350mW
*     > 350 to 500mW
No Stars > 500mW

Don’t get me wrong. This is a fine idea and should be applauded – if only set-top box makers could get anywhere near this.

The values are tight, but achievable.

But there lies the problem – they are achievable now. So, perhaps deliberately, the voluntary scheme has put a block on further developments for the foreseeable future – hit 30mW, get five stars, job done.

There is no incentive to go further. No one expects six stars.  

When they invented their respective energy efficiency schemes, fridge and washing machine makers at least made it tough on themselves.

They have G bad to A good, and A was not easy to get. However now they are easily reaching A ratings, and are moving on to a slightly ad-hoc AA and AAA scheme – at least the phone makers have left room for manoeuvre by choosing a decreasing scale.

So well done mobile phone industry, but not brilliantly done.

All this said, with my cynical hat on, I wonder if the EU Energy using Products (EuP) Directive had anything to do with the spontaneous emergence of this voluntary star rating system.

EuP is a ‘framework’ directive which allows legislation to quickly be bought to bear where voluntary scheme are not established.

And electronic product standby consumption was included in the first tranche of targets by the European Commission.

My thanks go to Power Integrations, a chip company that makes off-line PSU chips, and has a five star phone charger reference design, for providing the company links above.

See also: the European Commission Pilot Project on Mobile Phones


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