Five Percent: Conserve Energy

Climate Change Is Important: Energy Conservation is the First Step

November 14, 2005

Vampire Transformer Power Supplies

Category: Conservation,Save Electricity,Technology,Tips – Tom Harrison – 12:37 am

vampire-transformerMany electronic devices use transformers to convert the power you get from the socket into lower voltage more like that of a battery. These are the black “bricks” that are such a pain to plug in — some have dubbed them “vampires” since their two teeth stick into the socket and suck electricity. But many are built into the device. Most use electricity even when the device they are powering is turned off.

Culprits include:

  • TV’s that come on instantly
  • Almost anything that responds to a remote control
  • Computer monitors and computers, even in standby mode
  • Computer speakers and other devices
  • Cellphone chargers
  • Anything that has an LED light or an LCD display on it (and is plugged in)

The amount of power drawn can be small, or not. Several devices listed use as much as 22 watts all day and all night, and considering how many of these things are around a house, that could add up. Before castigating all of these, there are modern transformers, known as switched-mode power supplies that use a smaller, less expensive and more reliable way to achieve the same result. Here’s another good article on what uses standby power.

But one simple solution is to get a few power strips ($5.99 versions are fine) and plug in the parts you use infrequently and which don’t need to be on all the time or remember settings (computer speakers, monitors, printer, cellphones, small appliances, TV, receivers, DVD players, etc.) — the trick is putting the power strip in a convenient place so it’s quick to turn on the juice when you want it. Of course the power strips often have a light in their switch! (Update 2009 — get a smart power strip, which turns off power to vampires when they are not in use)

Here’s a gizmo that tells you exactly how much electricity is being used by a specific device, called “Kill A Watt” (tee hee). $26 seems like a pretty good deal to me.


  1. […] consume electricity when not being used, and only a little when it is. I have written about “vampire transformers“, and you can tell if you have one of these energy suckers just by putting your hand on it […]

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  2. […] when everything is “off”. This is the sum of all of those “standby” modes, vampire transformers, phones, clock, cable box (well, TiVo, actually) … and the whole computer setup. So this […]

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  3. […] a Smart Strip and move most “vampire transformers” to it, unplug […]

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  4. […] good points and was technically accurate. I was most excited that it raised the important issue of vampire transformers. All electronics use transformers; but until recently, most used ones that looked and acted like […]

    Pingback by Not All Are Vampires | What's on? — June 2, 2010 @ 1:59 pm

  5. […] on” electrical load accounts for about one third of our consumption. Perhaps more vampires? Doesn’t seem plausible.The only way to find out: measure each outlet with a Kill-A-Watt! […]

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