EMI filter performance plays a critical role in limiting emissions and also impacts the immunity of end-use equipment to electrical disturbances. Philip F. Keebler and Kermit O. Phipps EPRI, Knoxville, Tenn., USA Today, electronic equipment is commonplace in every residential, commercial, and industrial environment. Moreover, this equipment depends on increasingly complex … [Read more...]
Distinguishing between Surge- and Temporary Overvoltage-Related Failures of Metal Oxide Varistors in End-Use Equipment Designs
Equipment failure resulting from TOVs can be reduced by proper coordination of the line fuse and MOV. Philip F. Keebler, Kermit O. Phipps and Doni Nastasi EPRI Solutions Knoxville, Texas, USA Real world electrical environments in residential, commercial, and industrial facilities experience the gamut of undervoltage and overvoltage disturbances. Examples of undervoltage … [Read more...]
Optimized Lightning Protection for Higher Frequencies
George M. Kauffman, P.E. Frequencies above 4.5 GHz are being used in greater number for a wide range of outdoor communications. These uses include critical infrastructure applications where long lifetime and high availability requirements are paramount. In outdoor antenna applications, the exposure to lightning effects must be considered in most locations. When cables … [Read more...]
Reducing High Frequency Ground Currents to Zero
Patented system solution provides a more effective grounding method. Mark Panko Zero Ground LCC, Waukegan, IL, USA Technology and the electrical/electronics industry have changed at a dizzying pace. Among these many changes is the growing use of motors with adjustable speed drives (ASDs) or variable frequency drives (VFDs). An unforeseen consequence of using these efficient … [Read more...]
Accuracy of Flickermeters – Round Robin Results
Have the new standards improved measurement accuracy? Ken Hall Hewlett Packard, Roseville, CA, USA This article presents the results of an inter-laboratory comparison of a flicker measurement system. In the process of evaluating replacement equipment that met the new international requirements of IEC 61000-3-2,1 harmonics, and IEC 61000-3-3,2 voltage fluctuations commonly … [Read more...]
Developments in Lightning Testing Standards for Aircraft Avionics
Test standards are running behind the fast pace of technological change. Nicholas Wright EMC-Partner, Laufen, Switzerland INTRODUCTION Escalating costs and increasing complexity in modern aircraft has ensured that aircraft design and assembly is now a global phenomena. Today, subsystems can be designed, manufactured, and tested at any location around the world, then … [Read more...]
EMC Management and Design in Military and Aerospace Systems—Avoiding the Pitfalls
A systematic approach to EMC engineering and management is the best way of achieving compliance. A.S. De Beer, Ph.D Ruphus Technologies (Pty) Ltd., Lonehill, South Africa ABSTRACT This article focuses on the necessity of following a systematic engineering approach in the design and testing of military and aerospace systems that must comply with stringent EMC Standards. It … [Read more...]
EMC Pre-testing Simplifies NEBS Compliance
Introduction NEBS was developed by Bell Labs in the 1970s to standardize equipment that would eventually be installed in a phone company's central office (CO). Sorting out the acronyms, NEBS stands for "Network Equipment-Building System," a term used to describe the environment of a typical Regional Bell Operating Company (RBOC). To get a basic understanding of NEBS, visit … [Read more...]
Developments in Lightning Test Standards for Aircraft Avionics
Test standards are running behind the fast pace of technological change Nicholas Wright, EMC-Partner Laufen, Switzerland Introduction Escalating costs and increasing complexity in modern aircraft have ensured that aircraft design and assembly is now a global phenomena. Today, subsystems can be designed, manufactured, and tested at any location around the world, then shipped to … [Read more...]
Powerline Filter Cancels Surges
Series-mode filters contain residual surge voltage within normal power line voltage ranges while avoiding the inconvenience and costs of downtime J. RUDY HARFORD, Zero Surge Inc. WITHIN THE MODERN home and workplace, an ever-growing number of sensitive electronic systems are vulnerable to power line surges that can disrupt or damage vital equipment. Obviously, a filter that … [Read more...]
