This part of IEC 62317 specifies the dimensions that are of importance for mechanical
interchange ability for a preferred range of PQ-cores and low-profile PQI-cores made of ferrite,
and the locations of their terminal pins on a 2,54 mm printed wiring grid in relation to the base
outlines of the cores.
The selection of core sizes for this standard is based on the philosophy of including those
sizes which are industrial standards, either by inclusion in a national standard, or by broadbased
use in industry.