1.1 This standard applies to monocrystalline rectifier assemblies and equipment for supplying dc power from ac sources at frequencies up to 2 000 c/s and for dc power for voltages not exceeding 5 000 V.
1.1.1 In so far as it is applicable this standard relates also to controlled semiconductor devices having trigger characteristics. More detailed treatment of controlled semiconductor devices (that is, thyristors ) would be dealt with in a separate standard.
1.2 It does not apply to telecommunication rectifiers other than those for power supplied to such apparatus, nor to rectifiers used as auxiliaries to measuring instruments. Further, it does not apply to rectifiers based on polycrystalline semiconductor materials.
IS 4540-1968 history
1969IS 4540-1968 Specification for monocrystalline semiconductor rectifier components and equipment