Software developers have largely accepted the merits of agile development and commonly debate the value of one agile practice against another. Agile software development is a creative process that does not need all details to be defines in advance. Agile software development is a group of software development methodologies based on iterative and incremental development, →
AC current levels 0.25mA Maximum Leakage Current for Class II equipment in IEC 950 (Information Technology Equipment, I.T.E.) (no protective earth ground in the equipment, double insulation or reinforced insulation) 0.5mA Earth Leakage Current limit in IEC 601-1 (Medical Equipment) (this is general value, here are also other leakage current requirements in IEC 601-1) 0.5mA →
Unless you add a measurement instrument to your computer, you have only the sound card as an analog I/O port. You can use the sound card to digitize ac analog voltages but only within a limited range. You can, however, add some signal processing and measure a wider variety of signals, even those that produce →
Watch out for well-made (counterfeit) chips. Counterfeit parts are big headache. Saelae tells that they noticed first that many more boards than normal were failing the functional test. The USB chip was running hot. It turned out that every last part was an old revision corresponding to a different (obsolete) part number – the parts →
Ethernet switches are the ubiquitous building block of any intelligent network. Ethernet technology is deployed in virtually every organization’s data center. Wide Area Networking (WAN) and Metropolitan Area Networking (MAN) providers need to provide their customers with Ethernet services. Ethernet has also become the de facto networking technology in industrial automation even in mission-critical local →
EMC Basics #5: I/O as critical circuits article gives some useful tips on the EMC issues related to inputs and outputs. Digital inputs/outputs — The key concern for digital interfaces is ESD. A secondary concern is radiated emissions. Radiated susceptibility is rare with digital I/O, although possible at very high RF levels. The solutions for →
LED retrofit lamps have started to show up on retail shelves. Many players in the LED industry are giddy about the anticipated growth over the next few years. Nevertheless, the road to success for LED lighting will not be completely smooth, as there are a number of pitfalls to navigate. Bumps in the road ahead →
DC voltage levels: 0.7V Nominal voltage drop on normal silicon diode or similar semiconductor junction 0.8V Voltages from 0V to 0.8V are considered to be logic 0 on TTL logic IC inputs 1.25V NiCd, NiMH battery cell nominal voltage 1.5V Carbon and alkaeline battery cell nominal voltage 1.6V The voltage you normally get from a →
Write-only memory has been one of the best practical jokes on the electronics industry field. Write-only memory (WOM) is the antithesis of read-only memory (ROM). By definition, a WOM is a memory device which can be written but never read. The WOM concept is most often used as a joke or a euphemism for a →
Category 5 (CAT5) cable is a multi-pair (usually 4 pair) cable that consists of twisted pair conductors, used mainly for data transmission. Basic CAT5 cable was designed for characteristics of up to 100 MHz. Newer CAT6 cable is designed form 250 MHz. Nowadays there are applications where those cables is used to carry higher frequencies. →