Technical Articles

2011

• Tips for Choosing the Right Power Supply - Follow these guidelines to help you choose the right power supply for your application needs.
• Power Quality and Lighting (Part II) EN61000-3-2; Controlling Harmonic Emissions in Lighting Applications
  This article will continue the discussion of power quality in lighting and look at some of the ways to control harmonic content. There are several standards in use and the categorization of emissions limits varies from one standard to the next, though they have much in common.
• Power Quality and Lighting Systems - A Look Into EN61000-3-2 Class C
  There are several standards which exist for lighting industry compliancy.  It is incumbent on power supply manufacturers to produce supplies capable of meeting the appropriate lighting standards for safety and emissions.  The standard which most directly affects power quality is the standard for limitations on harmonic currents, or EN61000-3-2 Class C limits.  ANSI C82.77-2002 is the harmonic emissions specifications for luminaries in the United States.  
• Application Segment Overview – Medical
  Power sources in the medical field have similar characteristics as traditional commercial and industrial power supplies but have some unique attributes that typically centre on isolation and safety considerations.

2010

• Thermal Considerations for High Density DC Modules (154kb)
  Thermal management is an important part of the system design process. This paper presents some guidelines for good thermal design of systems using RO converters.
• Current Sharing for High Density DC Modules (144kb)
  Paralleling of DC/DC converters is often used to increase the output power capability of a single unit by connecting the outputs of two or more converters in parallel. By connecting the parallel pin of each module together, the units will share the load current equally within a few percent.  This paper focuses on how N+M redundancy and Hot Plug-in capability can be achieved.
• Medical Power Supplies FAQ Sheet (87.4kb)
  Frequently asked questions regarding Medically-Approved Power Supplies are answered. Learn more about what makes a power supply medically approved, if medically-approved power supplies are more reliable, how to know if you meet the necessary safety requirements, and if medically-approved parts are ROHS compliant.

2009

• Perspectives on Controversial Devices (MDT Link will open in a new window)
  If the intended purpose of a device upon which you were working went against your personal beliefs (e.g., an assisted-suicide machine), would you remove yourself or ask to be removed from the project?
• Principles of Power Conversion (1.02Mb)
  Overview of power conversion which seeks to acquaint the system engineer with specifications and implementation guidelines.
• MTBF & Power Supply Reliability (264kb)
  A general misconception is that Mean Time Between Failure (MTBF) is the same as the operational life of a product. In fact MTBF represents the statistical approximation of the percentage of units that will pass (or fail) during a products useful life period. MTBF should be considered as a measure of a product’s reliability, not product life.
• LED Drivers FAQ Sheet (43kb)
  Frequently asked questions regarding LED drivers are answered.  Learn more about key advantages, critical factors in selecting, and the difference between Mean Time Between Failure (MTBA) and Lifetime of an LED driver.  Ingress Protection (IP) ratings and IEC 61000-4-5 lightening protection levels are also explained.
• LED Driver Configurations (89kb)
  This paper discusses a variety (Series, Parallel, Matrix, and Multi-Channel) of configurations for LED drivers.  For each configuration a diagram is presented along with a description of basic operation, advantages, disadvantages, failure modes, and design options.
• New Energy Star Requirements Impact Powering of Solid-State Lighting (4.46Mb)
  Recently, a new Energy Star requirement for solid-state lighting (SSL) luminaires has been introduced that has implications for LED power supply designers and may also provide insight into future Energy Star requirements. Most people are familiar with the Energy Star logo but may not recognize its impact.
• Astrodyne Power MedAlert! #1 (3.13Mb) 
  The global adoption status of IEC 60601-1 3rd edition for medical power supplies is delayed, complicated by both the IEC's disagreement on assessing risk management and the industry's objections to including IEC 60601-1-9(environmental aspects). Discover the critical product approval issues and risks confronting medical power supply designers and specifiers.
• Perspectives on President Obama Forum
  MDT – “What changes do you see coming to the FDA and/or the industry as a result of President Obama's policies and do you expect the impact to be overall positive or negative?”
• Conforming With Worldwide Safety And EMC/EMI Standards
  Electronic Design – “Planning to sell your mains-powered product around the world? Then saddle up, because it takes more than approved components and a checklist to get those all-important marks.”

2008

• Brainstorm: Energy Star
  ECN – “What are your thoughts on the EPA’s Residential Light Fixture “Technical Amendment,” and their attempts to remove a “competitive disadvantage” for legacy technologies?”
• Medical Electronics Forum
  Electronic Products – “The constant monitoring of patients from the time they step into a hospital, the desire to reduce healthcare spending around the world, an aging population that requires increased levels of supervision and medical intervention, the capacity to deal with baby boomers — these are the most important factors that are driving the medical electronics industry today. Recently, we conducted a forum among industry experts from a variety of manufacturers to discuss issues and challenges the medical electronic industry faces. “

2007

• Evolving Standards Reshape Medical Power Supplies
  Power Electronics Technology - New medical equipment standards will improve safety and facilitate the process of international compliance.
• Digital Power Q&A
  Power Electronics Technology - What are the obstacles that prevent adoption of digital power technology?” In this edition of the Q&A, the same question is posed to experts from the power supply industry.
• Powering High Brightness LED’s
  EE Times India – High Brightness light emitting diodes (HB LEDs) are finding new applications and increased uses in all aspects of lighting.
• Brainstorm - SSL - Astrodyne
  ECN - LED illumination is rather unique, in that it is not relegated to a niche industry. It applies new technology across a broad variety of markets.

2006

• Lighting/Illumination Forum
  Electronic Products – “The term Solid State Lighting refers to the use of non-incandescent or excited-gas light emitters such as LEDs or electroluminescent devices in general lighting applications as well as in displays and other application areas currently dominated by legacy illumination. Recently we assembled, via teleconference, representatives from a variety of manufacturers involved in this developing application area.”