Some users believe that Windows is the best netbook OS. You might have read countless Microsoft-funded “studies” trying to persuade that Windows is already dominating the netbook space.
Linux is not going anywhere but up in the netbook market. 10 reasons Linux should be your netbook operating system article lists reasons why Linux is a much better fit for netbooks than Windows.
Starting next July 2010, every person in Finland will have the right to a one-megabit broadband connection. Finland’s Ministry of Transport and Communications has made 1-megabit broadband Web access a legal right, YLE, the country’s national broadcasting company, reported on Wednesday.The government had already decided to make a 100 Mb broadband connection a legal right by the end of 2015. According to the Helsinki Times when it reported the 100Mb target last year, the Finnish government said that no household “would be farther than 2 kilometers from a connection capable of delivering broadband Internet with a capacity of at least 100 megabits of data a second). Some variation will be allowed, if connectivity to some remote locations can only be arranged through mobile phone networks.
Finland is the world’s first country to create laws guaranteeing broadband access. Earlier this year France has made Internet access a human right.
I live and write this blog in Finland. Finland is the home country for me, Nokia and ePanorama.net web site.
An EE’s Guide to Survival Between Microphone and Voice Coil is an interesting slide set amde by Netherlands´ well known audio engineer Bruno Putzeys and put to web by Hypex Electronics and Grimm Audio. It was presented in AES convention at 2007. It is a very good presentation of the whole audio electronics path from microphone to speaker. If you are into audio electronics, read this slide set.
Prosessori magazine reports that traditional CRT display technology is dying much sooner than expected earlier. The sales of CRT based displays has practically ended in Western Europe, Japan and North America. And the sales of traditional CRT based TVs is also dropping very quickly on developing markets as well. According to Displaysearch research center people in China do not want anymore to buy old fashioned TVs with picture tubes. The change to flat screen displays is so quick, that the manufacturers of LCD TVs have hard time to produce as markets need. It is expected that 130 million LCD displays will be sold this year. And the prices will continue dropping.
Use right ground symbol in your electronics schematics and other drawings.
Earth-ground symbol represents a real connection to earth. That connection could be for example 10-foot-high copper-clad steel bar driven into the earth (at your premises or nearby provided by power company) or metal water lines. That earth ground is wired to the neutral of your house wiring at the breaker panel. You can reasonably use the earth-ground symbol for the ground pin on the electrical outlet. Your electronics equipment schematic should use the earth-ground symbol to indicate connection to the electrical outlet ground pin on equipment plugged to wall outlet.
It is bad practice to use earth-ground symbols for chassis common. You an use the chassis common wherever a power supply or circuit card connects to the chassis. In a circuit board schematic you can use chassis symbol when a standoff screws the PCB to the chassis.
Signal-ground symbols are most suitable for most circuitry on a PCB. A design can have several of these symbols, with notations to identify them.
Information source: EDN magazine article Draw the line: Isolation shields systems from shocking surprises
I had yesterday change to play a little bit with Nokia N900 mobile communicator at at Expert Expo in Helsinki. This brand new Nokia smartphone that you can’t yet buy anywhere, just pre-order. This device runs on Maemo Linux operating system and worked well. This device felt much better than Nokia N97. The tough screen seemed to work better and overall feeling was that the system was considerably more responsive. Linux will rock on mobile devices. There was even a X Terminal on that device available, so Linux hacker can do different things on traditional command line.
Isolator for digital audio is needed in cases where coaxial S/PDIF digital audio link forms a ground loop in your audio system. Typically in coaxial S/PDIF connections the coaxial cable shield is connected to equipment cases. This arrangement easily creates ground loops which can cause noise problems in various places in audio system. A suitable transformer can be used to isolate the coaxial S/PDIF signal and avoid ground loop problems (other option is to use optical connection instead of coax). Here is the circuit of the S/PDIF signal isolator I have used:
ELFA catalogue product 56-550-55 “PE65612 Trafo dig.siirt.” is a tranformer suitable for isolating S/PDIF digital audio signal. The manufacturer for this product is Pulse Engineering and their product code is PE-65612.
Ratio: 1:1
Bandwidth: 100 kHz-55 MHz ±3 dB
Here is a picture of the S/PDIF signal isoltor I built (box open):
More information on S/PDIF and related circuits can be found on my SPDIF document.
According to Reuters news article the European Commission has issued new volume standards for MP3 players on Monday this week. The new standards will require that MP3 players will play at a safe volume by default. There will also be a health warning so consumers who choose to override the default settings know the risks. Those new rules will require small technical changes to I-Pods and other MP3 devices. According to Yahoo news article “EU to set volume limits on MP3 players” new standards would see new players include a maximum sound level default at 80 decibels.
According to EU’s executive commission said the maximum sound levels of players now being sold range between 80 and 115 decibels with the supplied earphones. Using different earphones could add to those levels by up to 9 decibels. Above 120 decibels is equivalent to the level of noise generated by an airplane taking off.
John Huntington’s Entertainment Technology Site has an interesting posting Moving More Stuff Onto the Gravesend Inn Network that describes show technology used behind Gravesend Inn hounted house atraction. This system uses lots of industrial electronics (PLCs etc..) for a show control application.
Ground loops are a common problem in many experimental setups. A ground loop is an un-
wanted closed loop of cables in the setup, most often through the ground system. Those ground loops are often hard to find and debug. A Ground Loop Detector document describes how to build and test a simple system to detect ground loops in experimental setups. The two circuits used are from article “Simple system for locating ground loops” by P. M. Bellan. The ideas used on those articles are used in commercial product Loop Slooth. The idea in those circuits is to induce the test signal (100 kHz) into the ground system and then detect the amplitude of that signal in different parts of the setup with help of Rogowski coil based detector circuit. The basic idea in this circuit looks very promising. I have not yet tested the presented circuits, but at some laboratory tests the basic idea behind this circuit seems to work.
