Scientific paper ID 342 : 2009/1

Rail vehicle signal lamps used for signalling of train head or end in present are often designed as high brightness LED based lamps. Train operation safety is also influenced by proper function of its signal lamps therefore it is desirable to determine demands for safety of these systems. LED based signal lamps is possible to understand as a safety-related electronic system described in the standard IEC 61508 dealing with functional safety of these systems. Strict demands for system safety given by this standard are in compliance with hardware architecture of LED based signal lamp and its high-reliability components, contrary to common bulb signal lamps which are not suitable for functional safety assessment due to their design and low reliability level. This article deals with functional safety assessment of LED based control lamp hardware.