It’s average standby electrical power consumption is 236,46 mW. Standby means: I plug the adapter into an electrical outlet (230V) without connecting any device for charging.
I imagine that for a travel adapter, standby consumption is not that important, as one would use it only occasionally.
I created a .docm file with the following vba code:
I extracted the vbaProject.bin file from the OOXML file (.docm).
First, I removed all the compiled VBA code from stream 3. -s 3c selects the compiled code stored in VBA stream 3.
I open a copy of vbaProject.bin with a binary editor, and search for the bytes of the compiled code. And I set them all to 0x00.
Then at position 0x40 inside that stream, I write this ASCII test: “Cleaned by your favorite anti-virus!”.
Next I will shorten the compressed VBA source code. This is the compressed VBA source code (selected with 3v):
Value F4B0 is a little-endian integer: 0xB0F4. B are some flags, F4 is the length of the chunk of compressed VBA code. F4 hexadecimal is 244 decimal. I shorten this by 206 bytes. Thus I replace F4 with 26 (with a binary editor).
The result is that now, only the first line is readable, followed by some gibberish:
And to get rid of the gibberisch, I also shorten the length of the stream. It is 1380 bytes long:
That’s 64 05 00 00 (representation for a 32-bit little-endian unsigned integer).
I subtract 204, thus 1380 – 204 = 1176. Or 98 04 00 00. I use again the binary editor to make this change.
Result:
How did I find the values to subtract? Educated guessing and trial and error. Why 2 different subtractions? Because that was also the case in the original sample that inspired me.
I took a lemon, inserted a zinc and copper piece of metal (a couple centimeters deep) and connected an electronic load to draw 1 mA of current.
I let it run for a couple of hours until no more measurable current flowed.
The electronic load dissipated 0,034 Wh of electrical energy over that period. Hence, we can assume that the lemon battery delivered 0,034 Wh.
I’m sure the lemon battery could deliver more energy, by “resetting” it: cleaning the electrodes, inserting them in another place in the lemon, …
After a bit of searching through the web, I’m going to assume that a typical smartphone nowadays has a battery of 10 Wh. So we would need 294 times (10 Wh / 0,034 Wh) the electrical energy delivered by my lemon battery to charge a smartphone.
Except that, the 0,9 V that the lemon battery does deliver, is by far not enough to be able to charge via the USB interface. We need 5V, so, 5,555… lemon batteries connected in series.
On the screenshot above, you can also see that 37 mAh was measured. Notice that you can not compare this to the mAh rating of a (smartphone) battery, because both values involve different voltages.
Comparing this to a button cell like a CR2032 (Dutch Wikipedia article, because there’s no English Wikipedia article): the CR2032 has a 225 mAh electrical charge (on average) and a 2.0 discharge voltage. That’s 225 mAh * 2.0 V = 450 mWh. Or 13 times more than my lemon battery (34 mWh).
Here are more pictures of the lemon after the experiment (one week later):
They consume considerably less standby power than linear power supplies, like this one:
These contain a transformer to go from a high voltage (AC) to a low voltage (AC), and then contain some electronic components, for example a diode bridge and capacitors, to convert the low voltage AC electricity into DC.
I tested this old power supply I had lying around, and it consumed 1.6836 Wh when tested with my power meter during one hour:
That’s 14,75 kWh for a year. Which is about 10 times more than my worst switched power supply tested here.
So, if you are planning to follow the advice of energy experts here in Europe (and watch out, quite a few are not experts at all, just echo chambers) to reduce your electric energy consumption and save money, consider the following points (their idea is to unplug chargers you don’t use).
Start with your linear power supplies, they consume the most (a tip to recognize them: they are heavy compared to the switched-mode ones, because of the transformer; and they are old)
If you are going to do this daily, take into account mechanical wear and tear. Like on the pins of the power plug, the cables …
To avoid that extra wear and tear, you can plug your power supplies into a power-strip with a switch
I have a laptop power brick that regularly cause the power plug to spark when I plug it into a socket. That’s also something you want to avoid.
Didier Stevens 