Monthly Archive for: «July, 2011»

DC to AC Transfer – Measurement

General transfer capability is essential to the measurement of voltage, current, power, and energy. The standard cell, the unit of voltage which it preserves, and the unit of current derived from it… Read more

Jul 30, 2011 | Edvard

AC motors – Protection against short circuits

Every electric motor has operating limits. Overshooting these limits will eventually destroy it and the systems it drives, the immediate effect being operating shutdown and losses. A short circuit is a direct… Read more

Jul 29, 2011 | Edvard

Thermal-magnetic motor circuit-breakers GV2P with pushbutton control

Resistive heating explained in details

Whenever an electric current flows through a material that has some resistance (i.e., anything but a superconductor), it creates heat. This resistive heating is the result of “friction,” as created by microscopic… Read more

Jul 27, 2011 | Edvard

Materials with magnetic properties

All materials have magnetic properties. These characteristic properties may be divided into five groups as follows: Diamagnetic Paramagnetic Ferromagnetic Antiferromagnetic Ferrimagnetic Only ferromagnetic and ferrimagnetic materials have properties which are useful in… Read more

Jul 26, 2011 | Edvard

Fig. 3.2 Magnetization and hysteresis curves

How Stuxnet (PLC virus) spreads – Part 2

Continued from How Stuxnet (PLC virus) spreads – Part 1 » Read here Stuxnet is a computer worm designed to infect Siemens SIMATIC WinCC and S7 PLC products, either installed as part… Read more

Jul 23, 2011 | Edvard

How Stuxnet (PLC virus) spreads

How Stuxnet (PLC virus) spreads – Part 1

The Stuxnet worm is a sophisticated piece of computer malware designed to sabotage industrial processes controlled by Siemens SIMATIC WinCC and PCS 7 control systems. The worm used both known and previously… Read more

Jul 20, 2011 | Edvard

How Stuxnet (PLC virus) spreads
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