Five Percent: Conserve Energy

Climate Change Is Important: Energy Conservation is the First Step

January 2, 2006

Vampire Transformers — Can I Replace Existing Ones?

Category: Conservation,Household,Save Electricity,Tips – Tom Harrison – 8:55 pm

In the post Transformer Vampires, I talked about the inefficiency of the “bricks” that power so much of today’s electronic products. We probably have 20 of them plugged in somewhere in our house (we’re geeks, but the average house is said to have 12). I think new rules for Energy Star certification go into effect this year that require use of “switching power supplies” instead of transformers; switching power supplies do the same thing, but are 90% efficient, instead of around 50%.

But why can’t I replace my existing 20 vampires with switching power supplies? All they do is convert standard household AC to DC at a specified voltage and current. I think all I would need to know is:

  • Input voltage and frequency (110V, 60Hz in the US)
  • Output voltage and current, e.g. 7.0V, 1.8 Amps
  • Connector size; I would guess there are three or four standard sizes

All of this is written right on the back of the brick. Of course I would probably void the warranty on devices that use these transformers, but assuming they really are the same, why not? Then the question is, who makes them, and how fast can I set up a Yahoo or Amazon store to sell them :-)

I’ll see if I can find answers and report back.


  1. Still not sure if there’s a good solution for this one. Anyone have a pointer to a place that can sell replacement bricks?

    Comment by Tom Harrison — January 27, 2006 @ 6:25 pm

  2. […] that sucks a small current continuously. The Apple chargers appear to be the type that use “switching power transformers“, a simple digital circuit that not only switches off when not being used, thus drawing […]

    Pingback by Why the iPhone (actually) Matters | Five Percent: Conserve a Little Energy — May 18, 2008 @ 5:08 pm

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