February 9, 2011 9:49 AM Subscribe
How much current does an AC adaptor draw when it's plugged in but not powering anything, or the device to which the adaptor is attached is powered off?
posted by RockyChrysler to technology (18 answers total) 2 users marked this as a favorite
The AC adaptor for my document camera says "AC input 100-240 VAC 1.2A Max 50-60Hz 90VA-150VA; DC Output:12Vdc 4.0A" on it. Is there a way to use this info to determine how many kilowatt hours of electricity this device uses on a daily/annual basis? Specifically, I'd like to know how much power the AC adaptor draws when the doc camera itself is powered off but the AC adaptor remains plugged in. Why? Because our in-house "Energy Team" disconnects the AC adaptor jack from my camera several times a week but, when they do this, they always leave the AC adaptor plugged into the wall jack. Isn't the adaptor still drawing a small amount of current? Therefore, isn't unplugging the jack from the powered-off camera accomplishing little-to-nothing?