dc power converters ?

[mopinko]

i have heard that those ubiquitous dc converters/chargers use energy even after the devices that they charge are fully charged. is this still the case? is there some reason that they are designed this way? i mean, how hard would it be to have them shut off? what kind of power consumption are we talking about?
we have a brazilion of these things in my house. would it be worthwhile to put them on timers or something?

[MindPilot]

1. yes, it's true but the power consumption is miniscule

you already used way more than you would save writing this post.

[hunter]

2. If it feels warm to the touch when unused, it's wasting energy.

Some of these little power blocks are much more wasteful than others.

The mess of them under my desk are plugged into a power strip that I turn off when I'm not using the computer.

[NastyDiaper]

4. True. Plus if you ahve the A/C on you...

...have to spend another 2x wattage to cool that waste.

So the answer depends if you are running A/C, nothing or heat.

[Dora]

3. Yes, they continue to draw. As do many other appliances.

Stereos, televisions, vcrs/dvd players, even some coffee makers...

One way to stop the constant small but annoying power draw is to plug appliances, converters/chargers into a power/surge strip that has an off switch. Shut it off at night, or when you're leaving the house.

[Dogmudgeon]

5. This really isn't very much power, you know

The power a "wall wart" (miniature transformer) wastes is quite small. Even the "instant on" circuitry inside a TV set is pretty low-powered, and it will soon be obsolete when the cathode-ray tube is replaced by semiconductor and plasma screens.

And in the winter, the heat given off goes right to warming the air, saving about half an ounce of heating oil, a thimbleful of gas, or a few pennies' worth of electric in the course of the season.

Want to make a real dent in your power consumption?

-- Compact fluorescent light bulbs. Using dimmers with regular incandescent bulbs will also save a lot of energy and prolong bulb life.
-- Low(er)-power refrigerators.
-- Use the toaster-oven instead of the regular oven more often.
-- Get used to a little less heating and air conditioning.
-- Don't wash your clothes in hot water. Instead, soak them overnight and wash in cold.
-- Air-dry clothes until they're just damp and use the clothes dryer just to fluff them up and take the stiffness out of them.
-- Use the appliance energy ratings when making your purchases.
-- One word: Insulation.
-- More words? Thermally efficient windows will also help.
-- An attic fan will dramatically reduce warm-season air conditioning costs in most circumstances.

Don't worry about the small stuff like wall-wart transformers and Christmas lights. Save your mental space for making significant changes instead.

--p!

[mopinko]

6. i already do most of those things.

don't assume that someone who wants to do the little things hasn't done the big things. it's kind of insulting. i've done all of those things that i can do.
i wash most of my clothes in cold, but have too much laundry to let it soak overnight. ditto for hanging laundry out. that one actually kind of bugs me. so many of these things strike me as, we need to go back to women power, which doesn't cost anyone anything.
hopefully, next year i will be tearing down my rotting enclosed porch and replacing it with good solar design. new windows throughout, too.

[Dogmudgeon]

8. My apologies for the insult

There's a lot of that going around.

Maybe it's me.

--p!

[mopinko]

10. 'sokay

i have my days, too.

[skids]

7. Worry about your fridge -- but as to why...

...it's because they are made cheap, because consumers demand cheap things.

The cheapest way to convert from line power to dc is to step down using a transformer and then rectify the AC current and smooth it with a capacitor. When no output current is flowing the input coil of the transformer is still conected to the wall. While its resistance and inductance prevent much current from flowing through it, some still leaks through and something under a watt is wasted.

If we wanted to design a wall wart that did not do this, the coil would have to be severed from the wall using a relay. That's one more part. Moreover, there has to be a way to trip the relay when the device turns on, which will require that the device have some power to do so -- so you'd at least have to have a small button cell battery in there to retain some electrical power to detect when the device wants power and trip the relay. It would be a rather complex arrangement.

The "vampire" power initiative seeks essentially to raise standards so that the wall warts have higher resistance and inductance, reducing the amount of phantom load -- but not eliminating it -- because the above machanism is not something that is likely to be economically effective.

[mopinko]

9. my fridge was not cheap, but

i have a commercial fridge. i do not know about its efficicncy, but i do know that it has a much better exhaust fan than most. i keep trying to convince my hubby that he could wire in a computer case fan on my stand up freezer. that thing is a hog.

thank you for your explantion. i am trying to work if out so that wall warts are plugged in with times, so the only run at night. like all good vampires.