The Gigabyte MIB T5140 comes with a passive power supply which converts from 110/220V AC to 12V DC and has a labeled efficiency level of “V”. What the hell is that supposed to mean? Is that good or bad? I started to look at my other passive power supplies and found another label on the Toshiba R400′s. This time, it says “IV”. I guess they are meant to represent numbers, 4 and 5. But is higher better? I started searching again until I found the be-quiet notebook power, which has a “CEC” efficiency of “V”. That was the missing clue. CEC stands for Canadian Energy Commision  (Energy Star) and would be perfect for certifying power supply efficiencies. But how efficient is level “V”? I started going through white papers of CEC and they only mentioned what I-IV mean, showing that V is reserved for future use. How can I have a level V power supply then?

I started to dig deeper and finally found a paper about International Efficiency Marketing  Protocol, which finally revealed what efficiency a power supply has to have at what level including level V. And  here are the results. I created a little table to show you how the the levels correspond to the actual efficiency.

So when you look at those values, you can see that III and IV are pretty much the same, only level V shows real improvement. At the same time, when you think that you are using a PicoPSU with 96% efficiency, you would actually only get 87%*96%=83% total efficiency, which isn’t so great at all.

Spiele auf dem Handy (PDF)

1. The less the a Li-Ion battery cell is discharged, the more often you can charge it. Discharging 5% will allow you to charge it hundreds of thousands of times, while completely depleting it will drop the charging cycles to below 10 times. Luckily, most batteries will turn themselves off once discharged to 40%. Here is the thing about cheaper batteries promising to have more capacity than original batteries. Li-Ion cell’s power capacity is limited, so to increase the usable capacity, the manufacturer can either increase the battery size or allow deeper discharges. The second choice is a cheap way to buy “more” capacity by lowering charging cycles.
2. A Li-Ion battery will go bad on its own. The only question is how fast. When a Li-Ion battery is fully charged, it’ll lose about 20% a year of its capacity when stored at 25°C, or 35% when stored at 40°C. Placing a fully charged cell in the fridge at 0°C will slow down aging to about 6%. A only 50% charged cell will only age for 2% a year at 0°C or 4% at 25°C. This is the reason why notebook batteries are always half-charged when shipped. Lower temperatures will slow down aging, but never cool them below -25°C, which will break the battery.

So the big question is how should one use their battery to get the most out of it. A lot of friends ask me this question, as most known battery hints are either for Ni-Cd or Ni-MH batteries and not for Li-Ion batteries. I usually tell them to charge when it is convenient and use when needed. The thing with Li-Ion is that charging cycles will drop when discharged deeply. But if you keep your batteries always full, they’ll age a lot faster. So when the best trade-off is to charge them fully and use them right afterwards and recharge when you know you’ll be using it again soon.

Some people bring their own food to the university, but I like my lunch to be a hot meal, not some cold sandwich or similiar. So that’s not a solution for me. Until a few days ago, I didn’t had a choice and tried to avoid to eat at the university. Now everything changed, thanks to the Get2Card. With it, you can eat 2 for 1 at a lot of restaurants in Berlin, just like “Schweinske”, right next to the TU-Berlin. Their meals start from €5.00, so with the Get2Card and someone else who’s just as hungry as you, you can eat for €2.50 in a real restaurant, with someone serving you. The portion is about twice to tripple of the Mensa-Meal, so you get a really good tasting meal, with more than twice as much meat, salad and a side dish for as cheap as a Mensa meal. Did I already mention that it tastes really good as the meal is freshly prepared for you and not kept-warm like in the Mensa?

When you think about it, a real restaurant can make money when they sell food for €2.50 to you. It’s fresh and tasty and there is a waitress serving you. How come the Mensa, which gets financial support from the government, can’t offer it for the same price? Where is the money going? I mean the Mensa only offers meals with less than half of a portion of the restaurant for the same price without any service, but they’re still unable to make it eatable. Something fishy there… As for me, I’ll never go to the Mensa again.

This effect is caused by playing the sound “ba ba ba”, but showing the video for “ga ga ga”. You brain will see the lip moments and decide that the only possible thing to hear is “da da da”. People who can’t lip read at all will hear “ba ba ba” and hearing impaired will hear “ga ga ga”. You won’t encounter this effect in real life, because lips are always synchronized with the voice, but in some amateur dubbed movies, the is the possiblity of you hearing something which has not been said.

I’ve found a video on Youtube showing this effect:

Here is another with an complete sentence as example:

Premasking happens around 50ms before the loud sound, so you won’t hear anything up to 50ms (or maybe even more?) before a loud sound appears. But how can the brain know when it hears a quiet sound that there will be a louder one and ignore the quiet one? I learned this fact first in Prof. Möller’s lecture “Speech Communication” last week, but he couldn’t explain how it is possible. He suggested that it might be the time the brain needs to process the sounds. But the effect also happens for quiet sounds right before (<1ms) the loud sound, so this is not an explanation.

Well, today, I was in the lecture “Communication Acoustics” and we discussed this issue. As it was going nowhere again, I though of a model that could explain this effect.

First, you need to know that your ear works just like an ADU (analog-digital-unit), which sends out a signal to your brain whenever it receives a sound with a specific frequency. Louder sounds makes the ear send out more signals. Because signals are infinitely short, so to let you hear a continous sound, your brain counts the amount of signals over 200ms and then tells you what how loud the sound was for the last 200ms. This works just fine at normal sound volume. Imagine a child counting the signals and telling you every 200ms how much signals he has counted. Now what if there is a really loud sound? Well, the loud sound will cause a lot of signals need to be counted, let’s say 1000. But what if the child counting the signals could only count to 100? He will tell you as soon as he has already counted to 100, before the usual 200ms are over (buffer overflow)! Now you instantly react to the loud voice without much delay.

But what if there was a quiet sound 50ms (let’s say 5 signals) before the loud sound? The child counted the 5 signals and waits for 200ms more seconds to tell you, but after 50ms, there is the loud sound (1000 signals) and he counts 95 from it, so he reached 100 and tells you that 100 have been reached. Now you know the loud sound happened (right when the child told you) but the information of the 5 signals from the quiet sound are lost.

This is how I think premasking works. As far as I know there is no scientific explanation for this effect yet, but feel free to prove me wrong.

Every service hotline is usually redirected to a normal land line phone number. So currenty, when almost everyone owns a flatrate for land line numbers, the solution is quite simple: We need to find out which numbers the hotlines redirect to. Unluckyly, this is impossible to find out by yourself. You can either try to get to the number by asking a service representative for a number to call to abroad or look in the 0180 phone book. The 0180 phone books contains a lot of numbers and will save you a lot of money.

It started of when Frank ordered his new uebernotebook for a whopping price of € 1700 with everything anyone could every wish to have in a notebook. This includes Wireless LAN draft-n (450MBit/s), which can get as fast as 100 MBit/s effectively, unlike my Wlan-g network (54MBit/s) with only real 10 MBit/s. Every copied a file via Wlan-g? If yes, you know how long that takes…

Anyway, I wanted to upgrade to Wlan-n for a long time, but PCMCIA cards are not a solution for me as they usually have external antennas. After placing such a card in my notebook, I’d have 2 Wlan cards, one external, one internal, which is one too much. So that’s why I never upgraded until now.

Now when Frank ordered his notebook, I started looking for internal adapters and found out, that the internal Wlan adapters are not soldered on the main board but only mini PCI or PCIe cards! I couldn’t believe it at first, so I opened my Toshiba R400 and took a look inside. And there it was, a little PCIe card connected to 2 antennas. Next to it the Novatel UMTS/HSDPA modem and one free slot with “UWB” written on the board. So there is the missing UWB module of the R400 which was not allowed in Germany. I looks like I can not only upgrade my Wlan card but also get UWB in my notebook! A quick search returned me my new Wlan card, the Intel Wireless WiFi Link 4965agn for only €25! But unlike the Wlan card, a UWB could not be found. Too bad…

So I ordered my new Wlan card right away. But the 4965agn needs one more antenna than my old 3945abg, so I bought one of them as well on eBay for € 3,5. Right after receiving everything, I installed the new card with the 3rd antenna. It was really easy.

Wlan signal strength has improved a little, now I’m only missing the Wlan-n access point.

For more information, check out the German version “Subwoofer für den Lupo“.

I won’t discuss the cheap ones here, but the good ones. There are a few brands making these kind of protectors, for example 3M, Exim or Brando. Their protection quality is usually comparable, so the major difference is the cutting.

For my O2 Xda Diamond for example, I have tested 3 different kinds of screen protectors, the Brando Protector Plus, the 3M Vikuiti DQC-160 and the official HTC screen protector that came with the Xda Diamond. First one was the Brando, which felt nice, just like on my O2 Xda Orbit, but the top right corner, where the camera is, was missing. That destroyed the look and left the corner unprotected. So I bought the 3M next. They come not only with the screen protector but also with one for the bottom keys. They didn’t cut anything out for the camera, making the foil protect the camera too, which is great. But even after applying 2 of them, none of them glued perfectly to the screen. Dissapointed again… So I tried the official protector. Fits perfectly, glues perfectly. Perfect? Well… not really. It’s not scratch resistant at all. I already have a lot of scratches on it and I use it much more careful than I did with my O2 Xda Orbit with Brando protector.

So frustrated with all the protectors, I emailed Nina at Brando and asked her if they could fix their corner problem. After one month and quite a few emails, Brando has now made a new cutting for their Protector Plus Ultra-Clear and sent me 2 new pieces of it for free! Great products, great support and now highly recommended by me!

UPDATE: 3M just send me 3 new protectors for free! This time, they cut a hole where the camera is, so it is pretty much like the original screen protector except with a better quality.