CUI published two application notes. The first app note is titled: IEC 60601-1 Medical Design Standards-3rd Edition. The technical paper looks at the IEC 60601-1 3rd edition standard and its implications for engineers specifying power supplies for medical devices. The second app note is titled: Power Factor and Power Factor Correction. It explains power factor and its implications in today’s power systems.
IEC 60601-1 Medical Design Standards-3rd Edition
The IEC 60601-1 standard is complex, and the 3rd edition is far more complicated, convoluted, and confusing than its predecessor. There are related and intertwined standards in addition to IEC 60601, including formal collateral standards, which are directly related family members. There are some standards for guidance alone, and some you need to both follow and be formally certified as meeting and complying. There are many areas of conflict, confusion, ambiguity, and subject to interpretation. The conflicting elements of the 2nd and 3rd edition standards, coupled with its slow and (to date) incomplete rollout, further complicate matters. Simply shipping a medical device with basic documentation to a certification lab is no longer adequate. Comprehensive, carefully structured documentation is needed for the design analysis, the design process, and the design rationale with explanations for why certain elements were or were not included or undertaken.
Power Factor and Power Factor Correction
Power factor is on the list of concerns for designers of virtually every device that draws significant power from a mains socket, as well as for engineers in heavy electrical sectors. The power factor target, based on legislation, plus efficiency, component cost, and volume/board space need to be considered. For this reason CUI has designed active power factor correction into the vast majority of its ac-dc power supplies rated at 100W and above to help ease implementation and ensure compliance for OEMs.