Current is usually measured as a voltage drop across a known resistance. David L. Jones notes that this ‘burden voltage’ can be a significant disturbance in low voltage and low current circuits. His solution is the µCurrent. He provides a description and theory of operation as well as a circuit diagram for the device at [...]
Tagged build, circuits, measurementDC for data centers at Gigaom has some good history and a few interesting tidbits on a trend towards DC in data centers. They miss the big issue, though. The reason that Tesla and Westinghouse won out over Edison in establishing AC as the power distribution standard was about electrical power delivery over distance. With [...]
I dug out the old Ten Tec Triton IV (now called a model 540 as Motorola complained about using its trademark) transceiver so Dave, KA7VLL, and I could play with it. First up was to replace the panel lamps with LED’s. Under the idea that ‘when you get a new hammer everything looks like a [...]
Ideas to Integrated Circuits links to a number of interesting, first person, stories about the development of modern electronic devices such as the GFI. “The Characterization process of first silicon was an attempt to feel out how an IC would run in production. Things like beta and resistance would vary month to month. So a [...]
Roy, G4WPW, has a page with pinouts and wiring diagrams for the microphone connections on most common radios. For instance, to enable Icom’s microphones to be used on non Icom tranceivers, the diagram shows you need a 1 uF electrolytic, a 1k ohm half watt resister, and a 0.001 uF capacitor along with a 9v [...]
Lately, some folks have noted that Linux isn’t very kind to batteries in laptops compared to previous kernel versions or Windows. The cause of this brings to mind the ‘just works’ goal that developers express. The conflict is with standards. When it comes to PC’s, standards, especially those at BIOS level such as power management, [...]
It seems the Isostick is getting a lot of press lately. They must’ve put out a PSA? But I don’t get it. Why pay a couple hundred bucks for a USB memory stick and software when you can get the memory for a couple of tens and the software for free? See multiple boot from [...]
Way back in the dimdarks, software was distributed on floppy disks. That worked because most applications only needed a megabyte or two for the complete installable package. Systems pushed this a bit. Slackware and OS/2, for instance, often needed ten or twenty floppies. That is why the CD became a media of choice for systems [...]
The facebook announcement of specifications for their server farms has received interest from places like Tech.Blorge and The Register. Part of the reason is that it has ‘green tech’ tied to it and another is that it is presented as a open specification like in FOSS. The upshot of the server design, according to Frank [...]
Comparing the technologies between 1981 and 2011 can be a reminder of just how good we have it. Slashdot linked to StormDriver on a comparison of the Osborne portable computer and a modern iPad2. The Tech Archive: 30 years of mobile computing. The occasion is the 30th anniversary of the Osborne. The bar charts are [...]