Wonder if when I leave it connected to the outlet but not connected to the laptop, it still consumes electricity.
The answer for this is: YES, it will consume power, but such a few power that you may consider it irrelevant in terms of power consumption.
This component is responsible for converting the entrance AC voltage into another one in AC(if there is a load on the "output" side of this component. As you can see on the picture above:
Wikipedia have a good explanation about the operation of a trasformer:
I marked on bold the main part of explanation to explain you what will happend if there is no load on the trasformer(in this case, it means that there is no device "consuming" power from the transformer). If there is no load, the secondary part of the trasnformer will not "act" on the primary part of it. It means that you will only have the input loaded with the entrance impedance of the transformer, or, in this specific case, the AC power from your electric outlet to an inductor of 200uH in the transformer. A theoretical "ideal" inductor will not dissipate any power, but a real inductor will also have a resistive component that dissipates a small amount of power, usually due to the magnetic material in the core of the transformer producing "core losses"8. This will explain why you have a consumption of the AC adapter even if there is no "load" or on this case, if the notebook is turned off.
PS: This situation applies not only for your notebook AC adapter but to all adapters that have a transformer on it's entreance.
Hope being helpful with my explanations.
Yes it does.
The simple proof? Hold the charger in your hand while it's plugged in. Does it feel warm? That heat is generated from the electricity passing through the charger, even though it's not plugged into a laptop.
Some related links:
In general, yes it does. Unless there's a sensor that detects the connection to the laptop and cuts the circuit to the transformer, there's still electrons moving around.
You can actually measure this with the Killawatt http://www.p3international.com/products/special/P4400/P4400-CE.html
It's sold at thinkgeek.com as well
Not all chargers use a measurable amount of power when the laptop is plugged in but off. My laptop charger uses 0 watts as measured by a watt-meter. Yours might be different. Now it might not be an actual 0.000000000000 but it is apparently less than 0.1 watt which is the minimum my meter will read. Under load with my laptop running it's 25 watts.
Yes. There are still components in the laptop charger that uses a "little" energy when it is plugged in. About a year ago, there were numerous commercials on TV stating to unplug your cell phone charger when not in use due to the same reason.
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protected by Diogo Sep 12 '13 at 13:32
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