At 09:18 PM 8/3/01 +1000, you wrote:

>Something i've been doing lately is using the
>high-intensity leds. The 600mCd, 900 and 1600
>leds are getting quite cheap, and they are
>EXCELLENT for giving good light at 1mA or less,
>even 250uA gives a good indicator. I keep a
>drawer full of them and it's surprising how useful
>they can be for indicators of special things like
>very short pulse lengths (or short PWM) and
>for very low current indicators, especially
>when testing new circuits and you can't be
>bothered to keep attaching the CRO or meter to
>it, just put the led in there... Normally they
>can be seen from 50uA upward and safe to 50mA.

Yes! The red ones are more than reasonable.
GaAlAs red super-bright LEDs are the way to go if you can
live with red. You can use a little 1206 4 resistor network
and get the parts count down to almost zero. But for some
reason the product appearance is considered by some to
be better when you have yellow and green as well as red,
and run at ~10mA. ;-)  (Also there may be CE issues with
red for some applications).

The best ones are (expensive) but visible in a dark room
with literally a few microamps, none of this ~1mA offset
current that early GaAs LEDs had.

You've got a drawer full? That's a lot! I've only got about
10K of the 3mm ones on hand at the moment and it doesn't take
up much space. ;-)

Best regards,

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