blue led at night

[wuffwaff]

Hi,

I think everyone who uses those newer blue leds has experienced the nice colour during the day and the somewhat high intensity at night.

Wouldn´t it be nice if it (the led) would change it´s intensity according to the available light?

Does anybody have an idea how this could be done (LDR etc.) in a simple way?

William

[SHiFTY]

Those blue leds are very directional... just angle it so it is not shining at you and you should be ok... Otherwise a LDR might work but there is the hassle factor.

I like my blue LED!!!

[wuffwaff]

shifty,

I asked this question to avoid the hassle incase somebody allready has done something like this

Changing the direction won´t help a lot cause the whole room in kind of blue right now!

william

[Jason]

I have the same problem.

I use a bit of blutac to cover it up, or combine with some paper to dim.

Blutac gets pretty runny after a while of sitting on a on a big class A.

[MRehorst]

You could drive the LED with a current source that uses a photocell to vary the drive to the LED. In bright light it can be made to shine brightly and in darkness, it can be made dim. You'll have to put the photocell somewhere that it can see the room light level (front panel?).

Lots of el cheapo night lights do this...

MR

[phishead8]

An old TV of mine would do the same thing that you mentioned. It worked like a charm. I don't know why TVs stopped using that feature.
-Dan

[wuffwaff]

thank you all,

for the replies, they confirm what I already figured out but what I would really like is an answer like:

"buy this ldr, use a bc547 a 30VA trannie and 1k, connect them like this and it will work "

This thread was opened because I really don´t have time at the moment (or because I´m too lazy) to fiddle around with different types of ldr´s and do a lot of experimenting

william

[Peter Daniel]

Originally posted by wuffwaff


"buy this ldr, use a bc547 a 30VA trannie and 1k, connect them like this and it will work "

How about a switch to turn them off for a night? Simple and practical solution.

[tiroth]

Or a dimmer switch with a larger series resistor.

[Tomo]

Hey,

I got ... use to it. Living in city all my life, I can sleep in day light and have REM sleep. ... hehe.

I face LED inward and use indirect illumination. Use like white strip of paper or tape.

You can cut off the top of LED and sand it real well. Make that translucent. I think it would look more professional. BLED is a tad too bright anyways.

Tomo