This standard specifies performance requirements for electronic step-down convertors for use on d.c. supplies up to 250 V and a.c. supplies up to 1000 V at 50 Hz or 60 Hz with operating frequencies deviating from the supply frequency, associated with tungsten halogen lamps as specified in IEC 60357 and other filament lamps. NOTE 1 The tests in this standard are type tests. Requirements for testing individual convertors during production are not included. NOTE 2 Requirements for convertors which incorporate means for varying the lamp power are under consideration. NOTE 3 It may be expected that convertors complying with this standard will ensure satisfactory operation between 92% and 106 % of rated supply voltage of filament lamps with rated lives greater than 200 h and rated voltage less than 50 V NOTE 4 There exist regional standards regarding the regulation of mains current harmonics for end-products such as luminaires and independent control gear. In a luminaire, the control gear is dominant in this repect. Control gear, together with other components, should comply with these standards.