Groundloop

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 →

An electromagnetic field (also EMF or EM field) is a physical field produced by moving electrically charged objects. It affects the behavior of charged objects in the vicinity of the field. The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction. It is one of the four fundamental forces of nature. EMF measurement →

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 →

It is sometimes suggested that a mains power isolation transformer might be used to solve the ground loop problem. It is true, that many times a mains isolation transformer does help, but not always. A system with properly used isolation transformer is still safe, it can be even safer than system without isolation transformer. Remember →

One of the most common direct coupled noise sources is when the ground which is being used for reference or return is not referenced to earth as expected. This is especially prevalent in sensitive high-gain circuits. Grounding and Shielding Existing Equipment – How to effectively minimize EMI issues when best practices are not available is →

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 →

EDN magazine articele Ground loops by Howard Johnson (Signal Integrity) article starts with question why in audio circuit designers avoid ground loops at all costs, yet in digital products you normally see a solid ground plane holding hundreds of circuits. This is a good question and the article gives answers to that. Audio designers like →

A recent white paper from APC-Schneider Electric authored by Neil Rasmussen takes a hard look at grounding practices and the use of the signal reference grid in data centers. The Grounding and the Use of the Signal Reference Grid in Data Centers paper contends that signal reference grids are automatically specified and installed in data →

How to protect RS-232 serial connections article pointed me to a recent white paper from APC-Schneider Electric that explains specific power protection issues related to RS-232 cabling. The Protection of RS-232 Serial Connections document contends that the RS-232 port often represents the “Achilles heel” of computer installations which are otherwise well protected by UPS systems →