Re: [doc] Who can supply correct LEDs?

[Martin Gutkowski <webmaster@xxxx>]

Hmm. I'm not sure about this but I think that's down to the power supply 
and not the LEDs. Certainly LEDs do not have a lifespan in the 
conventional sense. Put simply, they *should* last forever.

If you have a battery charger or some other small domestic appliance, 
you often see this strobe effect, but this is because they're powered 
from the AC side of the transformer - LEDs only work when the polarity 
is connected correctly - otherwise they're diodes (light emitting diode 
for anyone who didn't know) which do not conduct when reverse polarised. 
I wonder if the buses you ave in Dublin run their lights directly from 
the alternator before its output is rectified.

Of course, I could be talking nonsense - can anyone clarify?

Martin

Emmet Cahill wrote:

> Another point to look out for is that to extend their life many replacement 
> LEDs switch on and off quickly which has the annoying side affect of 
> flickering (bit like a florescent light when it starts to give you a 
> headache). The buses here (Dublin) have them, but if you glance at the back 
> of the bus quickly you get a strobe effect and see multiple lights.
>
> My .02c
>
> Emmet Cahill