Document ID: chunk:federal_register_of_legislation:F2023C00919:body:0:p38
Version: federal_register_of_legislation:F2023C00919
Segment Type: other
Provision Reference: 
Character Range: 118600–121709

is maintained throughout variation transitions. No sharp variation of intensity shall be observed during transition. Stop lamps of category S4 may produce variable luminous intensity independent from the other lamps. It may be possible for the driver to set the functions above to luminous intensities corresponding to their steady category and to return them to their automatic variable category.
5.27.                                For vehicles of M and N categories, the applicant shall demonstrate to the Technical Service responsible for type approval testing that the electric power supply conditions for the devices indicated in paragraphs 2.7.9., 2.7.10., 2.7.12., 2.7.14. and 2.7.15. above comply, when the electrical system of the vehicle is in a constant voltage operating condition, representative for the relevant category of powered vehicle as specified by the applicant, with the following provisions:
5.27.1.                          The voltage supplied at the terminals of devices which, according to their type approval documentation, have been tested by the application of a special power supply/electronic light source control gear, or in a secondary operating mode or at a voltage requested by the applicant, shall not exceed the voltage specified for the relevant devices or functions as they have been approved.
5.27.2.                          In all cases of electric power supply conditions not covered by paragraph 5.27.1., the voltage at the terminals of the device(s) or function(s) shall not exceed 6.75 V (6 Volt-Systems), 13.5 V (12 Volt-Systems) or 28 V (24 Volt-Systems) by more than 3 per cent. The means of controlling the maximum voltage at the terminals of the device may, for convenience, be located within the body of the device.
5.27.3.                          The provisions of paragraphs 5.27.1. and 5.27.2. shall not apply to devices  which include an electronic light source control gear or a variable intensity               control being part of the device.
5.27.4.                          A report shall be attached to the approval documentation describing the methods used to demonstrate compliance and the results obtained.
5.28.                                General provisions relating to geometric visibility
5.28.1.                          There shall be no obstacle on the inside of the angles of geometric visibility to the propagation of light from any part of the apparent surface of the lamp observed from infinity. However, no account is taken of obstacles, if they were already presented when the lamp was type approved.
5.28.2.                          If measurements are taken closer to the lamp, the direction of observation shall be shifted parallel to achieve the same accuracy.
5.28.3.                          If, when the lamp is installed, any part of the apparent surface of the lamp is hidden by any further parts of the vehicle, proof shall be furnished that the part of the lamp not hidden by obstacles still conforms to the photometric values prescribed for the approval of the device.
5.28.4.                          When the