Is it true tht any kind of plug with a black box always eats electricity even when the device is not turned on

Answer 1

I assume by "black box" you mean an in-line transformer or similar gizmo.

I'm sure such things consume a small amount of power but I doubt it would be a great deal. It should be possible to measure it. I suppose you could leave all your devices plugged in for a time and watch your electric meter, then unplug them and watch again for an equal time interval. See how much difference there is.

I know some years ago they built old-fashioned TVs with an "instant on" feature so they could compete with newer solid state designs. Those things were basically on all the time except for the high voltage unit -- they were extremely wasteful and also a fire hazard.

So it all boils down to how much power your gizmos use when they are on standby. Maybe I'll attempt my own experiment and see what I learn...

Answer 2

The little DC supplies that are in "black boxes" & that plug into power outlets, do not use a power switch. Rather, they depend on a characteristic of electrical transformers ; that the current drawn from the primary side (the wall outlet) will be near zero, until the secondary load (whatever machine you are powering) begins to USE current. Some tiny amount is always being drawn, but this amount is a penny or two a year, on an electric bill.

Answer 3

I presume you are refering to a "wall wort" power supply??

If so, then yes. As long as it is plugged into a live outlet then the AC transformer inside will draw a little current and a little power.

The current might be as much as 50 mA which seems like it would be 5 or 6 Watts. But if the device is really off, the transformer behaves like an inductor, and the power draw from the outlet is more like 1 Watt or maybe even 0.5 Watt for a small wall wort.

This is pretty small, but it is drawing power 24/7.

Answer 4

I love urban myths
ok if its plugged in and the socket is turned off there will be no current flow
no power
without knowing what sort of black box I can only guess
and how do you define not turned on?
if its an instant start then it will only use power when the socket is turned on

Answer 5

Most of the electrical equipments eat power when they are plugged in even when its off. That is why it is always a good practice to unplug them when they are not in use. This can also help you when a storm comes you don't have to rush to unplug everything especially during the middle of the night. You can save a significant amount of money too. It also means longer lifetime for your equipments.

Answer 6

all power supplies used to reduce household current use a 100 to 1± transformer to approximate 12 volts other voltages can be reduced with electronic parts and semiconductors
Does the "black box" stay warm ??? it is consuming power.
But the primary circuit of the transformer is directly conected to the main power all the time..

Answer 7

It is true.

In fact the White House even produced an executive order encouraging staff to be less wasteful.

Answer 8

Yes, it is true. The current is still flowing through

Answer 9

No, are you in your senses?