What did the iPhone look like before it looked like an iPhone? Apple’s popular product looked radically different in the early stages of development (like many other high tech gadgets). Image of the Day: iPhone prototype from 2005 article gives you view of the early iPhone prototypes. Check out the article for interesting photos. That →
Why does not my tablet touch screen work when powered with third party mains power supply, but works with the original power supply? This happened to me. The power supplied I had were both for tablets (different tablets) and had similar basic characteristics (same current and voltage ratings). The reason why the other power supply →
In my previous posting Current sensor for multi core cable is talked about measuring AC current flowing on cable where you don’t get access to individual wires. In that posting I mentioned that I saw Modern Device blog article Current Sensor that seem to be doing exactly that. This sensor is designed for providing an →
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 →