In a Report and Order, the FCC updated the agency’s radio frequency device marketing and importation rules to accelerate the release of new wireless devices. Under the revised rules, manufacturers will be allowed limited marketing and pre-sales of wireless devices to consumers as long as the devices are not actually provided to consumers…

The draft guidance, “Remanufacturing and Servicing Medical Devices,” defines remanufacturing as “the processing, conditioning, renovating, repackaging, restoring or any other act done to a finished device that significantly changes the finished device’s performance or safety specifications…

n the world of product safety, it could be said that there are two basic approaches to risk mitigation, proactive and reactive, with proactive being the preferred choice. Most would agree with the adage that “an ounce of prevention is worth a pound of cure,” but in truth, this oversimplifies the reality in which product manufacturers operate. As with most things in life, things are rarely black and white but rather a continuous spectrum of shades of gray.

To this, there are many competing aspects in all commercial product ventures. Could you make a product that was fully reliable under all conditions? Perhaps, but the odds are that it would be a commercial failure as it would take an inordinate amount of time to produce and be prohibitively expensive.

Editor’s Note: The paper on which this article is based was originally presented at the 2020 IEEE International Symposium on Product Safety Engineering held virtually in November 2020. It is reprinted here with the gracious permission of the IEEE. Copyright 2021 IEEE.

Depending on the technical discipline, patterns created by the flow of electrical current have been referred to as dendrites, water trees, or fern patterns—the general term is Lichtenberg figures [1]. The terms dendrite and water tree are generally applied to dielectric failures [2], while the term fern patterns have been applied to patterns sometimes formed in epidermis from a lightning strike. The term fulgurite [3] refers to patterns of fused silica formed from a lightning strike to a soil or sand surface.

Dielectric breakdown of the ethylene propylene rubber (EPR) insulation of electrical power transmission cables has been variously described in the literature as water trees and dendrites. The pattern of formation was first realistically modeled in 1984 and referred to as the dielectric breakdown model [5]. Dendrite patterns can form in circuit assemblies by the stress of an electric field [2] and in electrical insulators (dielectrics) from electric field stresses [5].

roduct liability has created problems for manufacturers and product sellers for many decades. These problems have been exacerbated by the expansion of product liability laws throughout the world. In addition, there has been a proliferation of safety regulatory requirements, starting in the United States (U.S.) and then moving to the European Union. In addition, countries such as Japan, China, Australia, Canada, Brazil, and South Africa have all recently established or strengthened their product safety regulatory regimes and requirements.

This all creates additional challenges for manufacturers who want to comply with all laws, regulations, and standards in any country where they sell their products. Such companies may also need to consider safety requirements in countries where they do not sell products if they believe that these requirements establish a floor for safety that they want to meet.

This article will discuss the basic kinds of defects that can be alleged in any product liability case, the law as it pertains to compliance with standards, and some tips on how to deal with the issue of standards compliance.

rule-of-thumb in EMC and RF (hereinafter termed “The Rule”) is that bayonet connectors (BNCs) leak above 10 MHz and are thus to be avoided for radiated measurements. Threaded connectors such as TNC, N, and SMA are used for radiated test work. Having said that, to this day my test facility has some old biconicals and rod antennas with BNC connectors. What’s going on?

On one hand, there is The Rule. On the other hand, it doesn’t seem likely that the manufacturers of otherwise fine test equipment would use a leaky connector.

A measurement of connector leakage performance – BNC vs. threaded – is revealing.

One might imagine a connector leakage test to look like Figure 1, where a signal is piped through a length of coaxial cable, and the radiation due to that signal is measured externally.

his is the fourth article in a series of articles devoted to the design, test, and EMC emissions evaluation of 1- and 2-layer PCBs that contain AC/DC and/or DC/DC converters, and employ different ground techniques [1, 2, 3]. In this fourth article, we are still focused on the DC/DC power converter board (2-layer PCB). In this article, we will evaluate the implementation of several EMC countermeasures and present the radiated emissions results according to CISPR25 Class 5 limits.

The third article [3] presented the radiated and conducted emission results from the baseline design which did not contain any EMC countermeasures. The results showed multiple failures in both radiated and conducted emissions. This fourth article presents a systematic approach to improve these failures by populating the PCB with optional EMC countermeasures on component pads that have already been designed into the PCB layout and showing their impact on the radiated emissions. The countermeasures are presented in an order that we would typically follow in an EMC diagnostic session where, due to time restrictions, not every single permutation of EMC countermeasure will be tested. The EMC countermeasures are illustrated in Figure 1 as purple dashed boxes labeled EMC-A through EMC-F.