IEC 60477-2:1979/AMD1:1997

IEC 60477-2:2022 applies to resistors intended as laboratory AC resistors for use over a range of frequencies from DC up to a stated frequency which is not in excess of 1 MHz. Such resistors are hereinafter referred to as "AC resistors". In addition to satisfying the requirements of IEC 60477-1, resistors satisfying the requirements of this document are designed to have a small variation of resistance and a small phase displacement over the stated frequency range. IEC 60477-2:2022 cancels and replaces the first edition published in 1979, and Amendment 1:1997. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) extended the AC resistor frequency range to 1 MHz; b) updated the terms and definitions according to IEC 60050 series; c) added the definition of AC/DC difference of an AC resistor; d) added the resistor classification according to the AC resistance or AC/DC difference index; e) updated the classification according to the AC resistor construction; f) updated the safety symbols and requirements according to IEC 60477-1; g) added the three-element equivalent circuits of an AC resistor in Annex C; h) added the annex on constructions of AC resistors.