In article ,
"Dave Plowman (News)" writes:
In article l.net,
Dave Liquorice wrote:
**** LED's via ebay, can't quite imagine LEDs running at 3ma I have
some low current ones that aren't very bright they run at 2ma.

Have a cheapo NAS with a blue LED indicator on the front. A night it
would be dazzleling and light up the entire room. I "got at it" and
inserted a series resistor to drop the brightness. In the process I
found it would glow with the leakage current through dry fingers
lightly holding the wire. Eventually settled on 50 uA (micro amps)
and it was still on the bright side.

Yup. I changed the old red 5mm LED in my Quad 405 to a modern blue one,
and was amazed how low I had to set the current to make it acceptable.

Yes, I have a row of 6 diagnostic LEDs on my Raspberry Pi heating
controller using a few different colours. There's one blue one
(indicates boiler burner on, i.e. flame colour), and ISTR I ended
up with 1/20th of the current through that one compared with the
othees, and it's still much brighter.

It wouldn't surprise me if it was more efficient to make a red LED
using one of the blue ones, a red phosphor, and a blue blocking filter,
inspite of the Stokes shift and other losses.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]