Inductive amplifier is a type of test instrument that does not require electrical contact to detect an AC wire under voltage. The conventional use of the inductive amplifier is finding the location of hidden wires and breaks in them. Inductive amplifiers can also be used to find an individual cable pair in a telephone cross →
Any real-world security system is inherently complex. Making them safe and secure is hard. Controlgeek Blog has an interesting pointer and summary on on a very interesting white paper How Complex Systems Fail. I also found his paper, which is only a few pages long, a fascinating read (like John Huntington and Schneier on Security). →
I just saw news in several news sources (check the links on this article to get to them) that STMicroelectronics wants to lure more contracts from the world’s biggest phone-makers with a new trick: touchless screens. The new display is the touch screen, except that it does not touch, but fingers are several centimeters above →
There are many ways to measure current. The traditional methods of taking current measurements by inserting a shunt resistor or using a current transformer have the disadvantage of having to break the circuit conductor. For current transformer there are also models that can be installed in place without cutting the cable (more expensive and usually →
Selecting the Best Battery for Embedded-System Applications article tells that non-rechargeable (primary) batteries find wide use in mainstream embedded-system applications. This category of batteries includes alkaline devices, which manufacturers typically fabricate using manganese dioxide and zinc powder with a caustic alkali of potassium hydroxide as an electrolyte. The nominal voltage of an alkaline cell is →
Inadequate shielding and bad grounding are often blamed when measurements are inaccurate, especially in high-impedance applications. Understanding grounding, shielding, and guarding in high-impedance applications article tells tells that in fact, shielding and grounding problems are frequently responsible for measurement errors, but many test system developers aren’t quite sure why. Many measurement errors can be traced →
Here are some pointers to useful audio electronics design articles that touch grounding and shielding issues: Grounding and Shielding Audio Devices Grounding The Circuit Designer’s Companion →
Balanced inputs and outputs have been used for many years in professional audio, but profound misconceptions about their operation and effectiveness still survive. Conventional wisdom about them is sometimes wrong. Balanced Line Technology web page gives you a good look at the balanced line technology in audio applications. The balanced line technology is also applicable →
My article Signal reference grids in the data center shows that different types of data communication interfaces are classified into susceptibility classes: Data communication interface classification Susceptibility class: Low immunity Interfaces in class: Parallel ports, RS-232 ports, Proprietary back-plane, Video cables Characteristics: Copper cabling with ground referenced signals. Any shift in ground voltage between the →
Grounding and shielding is an often misunderstood process. It is common to hear quotes ranging from “it’s just black art!” to “the rules change all the time!” and “there’s no way to understand it!” These statements are often repeated but not true. There is a process, it hasn’t changed, and the more one knows about →