This is California's version of EPA's "Energy Star" program for power
adaptors. The goals of both programs are similar: reduce power use by
improving both stand-by power use and operating efficiency. There are
similar programs in other parts of the world, including Europe You can
read more about them at
The big difference between them is whether the standard is recommended
(Energy Star) or mandatory (California).
Switch mode supplies aren't the only way to meet the standard, but they are
the design choice for cost reasons. Transformer lamination prices have
risen dramatically, along with other grades of sheet steel. Feel the weight
of your cell phone charger: if it was made in the last few years, there's
probably no line-frequency transformer inside. Lap-top computer power
supplies have been switchers for years, because a line-frequency
transformer powerful enough is too bulky and heavy for that market.
The encouraging news is that it's possible to make them RF-quiet, and most
reputable brands *are* reasonably quiet. The discouraging news is that it's
cheaper to build noisy ones, there are plenty of customers who care only
for the lowest price, and some of those customers are Famous Name Brands
that re-sell low grade products under their own name. You don't always get
what you thought you paid for.
>"Cortland Richmond" <email@example.com>:
>The California Energy Commission has just published an efficiency standard
>dated April 2005. It requires that by 1 July 2006 most appliances made or
>sold in California meet state mandates for efficiency. For example, single
>voltage external power supplies* of between 51 and 250 watts must be 84
>percent efficient, and consume not more than 0.75 watts when not under load.
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