Technical Bulletin – September 2018 (2)

Safety Approvals: Limited Power Sources and Types of Limiting


Most industrial AC/DC power supply labels are littered with a wide assortment of agency approval marks. In examining the approval marks on lower-power adaptors, one may occasionally come across the three letter acronym: LPS. We receive inquiries almost weekly regarding the LPS compliance of our power conversion products, and this article aims to take a deeper dive into exactly what constitutes an IEC 60950-1 recognized Limited Power Source.
On the surface, LPS compliance seems quite simple. One could render a guess that any given ITE power adaptor with a
nameplate power of less than 100W is LPS complaint, and may often be correct. In reality, determination of LPS compliance is a bit more complicated, and there a number of different ways that a power converter can achieve this recognition. In this months technical bulletin we will take a close look at the four different ways a power supply can meet LPS requirements, as well as detail some of the compliance testing stipulations presented in the standard. Read more (view pdf) >>

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