29-09-2011, 09:25 AM
There are some interesting differences wrt filament to LED lamps. Personally, I struggle with LED due to the intensity of light especially at close quarters. However, with incandescent lamps being forced out of production, LED is technically mandatory. It has obvious advantages such as decreased maintenances, a more predicatable and gradual degredation of its light output, reliability etc.
One of the early concerns levels at LED on mainline was the colour differences plus the hot spot wasn't in its traditional place. Colour can be altered and I was actually involved in a trial where mixing of colours on a new signal head produced odd colours or undesired aspects! Remember, signal indicitions are there SOLELY to supply information to the driver that will allow them to control the train appropriately.
That said, for me the biggest issue is still the brilliance at close up distances which are required due to the light levels mandated in standards written for incandescents. There is also a large environmental cost due to the constuction of the LEDs, partially in their creation and mostly in their distruction but that, in this case in an aside.
Jerry
One of the early concerns levels at LED on mainline was the colour differences plus the hot spot wasn't in its traditional place. Colour can be altered and I was actually involved in a trial where mixing of colours on a new signal head produced odd colours or undesired aspects! Remember, signal indicitions are there SOLELY to supply information to the driver that will allow them to control the train appropriately.
That said, for me the biggest issue is still the brilliance at close up distances which are required due to the light levels mandated in standards written for incandescents. There is also a large environmental cost due to the constuction of the LEDs, partially in their creation and mostly in their distruction but that, in this case in an aside.
Jerry
Le coureur