If I turn off the light switch or any switch that use up electricity, Do they continue to use up electricity.?

Question

Just like the tv and other major appliances, eventhough they are turned off they still use up electricity. is it the same on light switches?

Answer 1

Consumer electronics run on power supplies that are either internal or external to them. An example of an electronic device with an internal power supply would be a TV or stereo (has a cord that plugs into the wall). An example of something with an external power supply would be a cordless phone or answering machine (has a transformer that plugs into the wall).

If a device has an internal power supply, the power switch probably cuts off the AC power to the internal transformer. Unless it's in a stand-by mode, in which case the input side (primary) of the transformer stays energized and the rectified DC durrent out of the power supply is cut off.

If a device has an external power supply, the transformer is always energized as long as it's plugged into an energized outlet.

If a device with an internal power supply is in stand-by or if it has an external power supply, it is using up some electricity all the time. Not as much as if the device were operating. But, it is wasted electricity. All it's doing is heating up the transformer.

Answer 2

Unlike most high tech devices that you've mentioned that do continue to use electricity after you've turn it off, the circuitry involved in a light bulb is very simple. Turning the light switch off physically disrupts the electrical flow between the power source and the bulb, and therefore is unable to consume power.