Pulsing HDD LED

[Courage]

I've actually been looking for a pulsing HDD activity LED for some time. Basically, instead of aburptly turning on-off I want it to fade in or out or more accurately "pulse". It'd also be nice to do with a standby LED. Its just that I find the on-off-on-off rather boring...

[FrooP]

could try it with a 10µf capacitor

americans, your turn, dunno how to explain it :(

[Scotty]

would defiantly be something to see.

No idea how the hell to do it though

[Bopher]

Maybe this will help.
http://blog.makezine.com/archive/2006/06/fading_eyes_led_project.html

My experience in electronics is limited to basic high school understanding. But I suppose if you regulated the power right you could replace the 9v with whatever power is fed into a regular LED light wire from the motherboard. Maybe someone with better understanding can get something off of this.

[Woztron]

Using a small capacitor wired parallel to the LED would blend the transition from on to off and vice versa. The way it works is drawing some of the power away from the LED when it goes from off to on. The way the capacitor powers up and down is an exponential function, so more power early than later and drops away to 0 power draw. When this happens the LED is Full brightness.

Same happens in reverse, capacitor keeps the LED bright before it is slowly drained to nothing. I could work out how big a capacitor you'd need if i could find that text book, but i'd start small and work your way up til you get the look you want.

Word of warning, no idea if this is the right way to do it, or if it'll screw your mobo up. I think it will work though...

[Courage]

The capacitor sounds like a good idea, maybe I should give it a try. Maybe I can isolate it from the motherboard circuit uisng an oscillator or something, that why I won't risk damaging my motherboard if the LED shorts or something.

[Roughhouse]

If you want to protect you MB when you wire up the HDD LED, you might want to place a diode in line before the capacitor and LED, just as a safety precation. This should help keep any back feed into the MB. Of course I am no electronics expert, so I would keep looking and get more informed peoples advice. Also I would suggest getting a breadboard and trying this seperate form your pc.

[Woztron]

Where's your sense of adventure ;)

As far as i've been able to work out they're shouldn't be any real chance of MoBo damage, but i couldn't find my bag of elec components to test it out.

[Nagoshi]

Just test it out on a old machine if you have the chance. Or something you don't use... like a floppy drive LED or a CD drive.

[xmastree]

I saw a circuit somewhere... Watch this space whilst I go a searchin'

Here ya go:
http://metku.net/index.html?path=mods/hdd_eyez/index_eng

That ought to give you some fade in/out ideas.