[VAC] Re: ail lights

["Dr. Gerald N. Johnson, electrical engineer" <geraldj@xxxxxxxx>]

Since LEDs don't heat (much), and don't depend on heat for their output,
they generally last two or three orders of magnitude longer than
incandescent lamps. Their light production efficiency is getting better
than incandescent lamps. They also are totally potted so there's nothing
to flex with vibration.

The best of the stop lights I've seen replaced the entire lens with LEDs
mounted side by side. A tail light would be most effective that way
also.

Unless the current to the LEDs is controlled (they are a current device,
not a voltage device, e.g. if the applied voltage changes a little the
current can change a lot) and adjusted for temperature, light output
does change with temperature. But since the individual LED only needs
about 3 volts, the lamp assembly needs some built in current limiting.

Gerald J.