This lamp here any other by inches!
First: Why you need any illumination? If, for example sitting (as a passenger) in the car or outside in the balmy summer night on the terrace and a little have to work or want to tap only a few e-mails, the environment is just so dark that the screen even at the darkest setting is still so bright that everything around it disappears. We find not only the keys on the keyboard do not again (yes, I can also write blind with 10 fingers, but sometimes you need special characters or the FN keys) but is also very hard on the bright screen and the dark environment. Who has dealt before with ergonomic and eye-friendly furnished computer workstations, know that you should adjust the screen brightness to the ambient light. (By the way, most people have their monitors set much too bright - indoors should be about 100 cd / m² have, which is almost at the bottom of the brightness scale with most monitors.) Well, so much for that.
Thus, this lamp illuminates not only the keyboard, but all the same work, and in such a uniform and bright that I was (as an electrical engineer) not bad surprises. Here, the ray of light does not interfere on the screen, only possibly existing dust on the screen you can see a little better. : D Klemmt to the lamp on the side of the laptop lid, you can easily have put an A4 paper aside and read very well.
To use: The lamp is folded very stable and 2 cm thick, 5.2 cm long and 6.3 cm wide (these are respectively the thickest parts, the front it is only about 1 cm thick). For mounting one works around the lamp, pull the USB plug with its cable out of the housing, clamps the terminal to the laptop lid and put the USB plug into a free USB port of the laptop. The terminal includes laptop lid to about 1.5 cm thickness.
After use simply pull the USB plug from the laptop and put it in the recess provided in the lamp. Then you press's little buttons and - presto - the cable rolls in the lamp and is securely stowed.
Should also be noted that the inside of the terminal is rubberized, so the laptop lid does not scratch and keeps the terminal well.
Those looking for a sophisticated lamp that illuminates the keyboard well (and the surrounding work), has here what you wanted. The Hammer.
I'm e-technicians I have the same time housing and screwed a little measured:
147mA current at 5,00V voltage (USB voltage) correspond 0,74W total consumption.
This 3.2V drop across the LEDs from (0,47W for light), 1.8V drop over the resistors from (0,27W losses).
This results in an efficacy of 64%.
The low efficiency is not really chic, considering that the LED lamp is so fed from a battery and therefore the laptop by holding less long. But since all the LED bulbs that I have seen so far are built (LED with series resistor), which is okay. Technologically correct would be to incorporate a constant current source, which would be more expensive, but more economical. So you could bring the efficiency is estimated at about 90%.
I once counted short, my laptop keeps his battery (62Wh) around 4:30 hours, so he consumes about 13,8W. The LED lamp needs 0,74W again, we arrive at 14,54W, resulting in a battery life of 4:16 hours. So me steals the lamp for about one quarter of an hour duration. This is only a calculation example for my frugal laptop in laptops to 2:15 runtime then 7 minutes would steal.
Enough counted.
In summary, I would like to create the following Pro / cons list:
Per
+ Very bright
+ Uniform illumination
+ Stable seat
+ Thought collapsible
Contraindications
- Unfortunately, you can not adjust the brightness. To me it would be enough significantly darker.
- Hides the front edge of the lamp a little (paint over if need be with black nail polish)
- Poor efficiency (but what I have so far seen better at any USB lamp)
