BS EN 61605 2017 pdf free download.Fixed inductors for use in electronic and telecommunication equipment — Marking codes
This document specifies marking codes for fixed inductors.
The colour code specified in Clause 3 gives a colour coding for fixed inductors. It is intended for use with the values of the E3 to E24 series as specified in IEC 60063.
The code specified in Clause 4 gives a system for marking inductance values by means of digits and letters.
The code specified in Clause 5 gives a system for marking the tolerance on inductance values by means of letters.
The code specified in Clause 6 gives a system for marking of date codes on fixed inductors by means of letters and digits.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 8601 , Data elements and interchange formats – Information interchange – Representation of dates and times
3 Colour code for fixed inductors
3.1 General rules
Colour codes for fixed inductors should be expressed in “bands”. If other shapes than bands are applied, the relevant specification shall prescribe their configuration, placement and identification.
Colour codes for fixed inductors shall consist of four bands. The first three bands shall indicate inductance values and the last band shall indicate tolerances.
Inductance values shall be expressed by two significant figures and another figure expressing multipliers.
Colour corresponding to significant figures, multipliers and tolerances shall be as given in Table 1 .
The first two bands represent significant figures and the third band specifies the multiplier. The basic unit for the inductance value shall be expressed in µH. The first band shall be the one nearest to the end of the inductor and the bands shall be so placed and spaced that there can be no confusion in reading the coding.
Any additional coding on fixed inductors shall be applied in such a way as not to confuse the coding for value and tolerance.
4 Digit and letter code for inductance values
4.1 General rules
Nominal inductance values shall be expressed in three characters of letters and digits.
Where inductance values are equal to, or greater than, 1 0 µH, the first two characters indicate significant figures and the last one indicates multipliers. In this case, cardinal numbers for the multiplier shall be as given in Table 2.
Inductance values less than 1 0 µH and equal to, or greater than, 1 00 nH shall be identified with two numbers representing the significant figures and the letter (R) designating decimal point
location µH, and the letter (N) designating decimal point location of nH for the inductance value of less than 1 00 nH.
4.2 Examples of digit and letter code for inductance values
Examples of digit and letter code for inductance values are shown in Table 3.
5 Letter code for tolerances of inductance values
5.1 Symmetrical tolerances
The letter codes shown in Table 4 shall be used to indicate the symmetrical tolerance on inductance values.
These letter codes shall be placed after the inductance values.
5.2 Other tolerances
For tolerances for which a code letter has not been laid down, the letter A may be used. The letter A indicates that the tolerance is to be identified in other documents.
6 Date code system for fixed inductors
6.1 Single-character code for year and month
Date codes of year and month in single-character shall be expressed in the code system shown in Table 5 and should be repeated every four years.
6.2 Two-character code for year and month
Where the date codes of the year and month of the manufacture are required as two-character codes, the code system shown in Table 6 and Table 7 shall be used.BS EN 61605 download