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FubbHead
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Power & HDD activity LED sharing?

Thu Sep 15, 2011 7:23 am

So, have put together a small server, using a Fractal Design Define Mini case. Very nice case indeed, especially for the money! There is just two tiny, tiny issues, but something I just might be able to fix with some help of you guys: there is one single LED available, and it is a tad too bright. :o

My idea for a solution:
1) make power and hdd share that single LED (ie, when there's no hdd activity, the LED has a constant dim light, but will flicker with a tad brighter light with hdd activity.)
2) make the LED max output a tad dimmer

I guess it involves using resistors on the different outputs and then combine them over the LED, but I would be grateful for some help with what voltages and resistances we're talking, and in what way to combine these outputs. Or perhaps a pointer to some nice DIY walkthrough. :)
Amiga 1200, 68020@28MHz, 4MB+2MB RAM, Conner 80MB harddrive
 
Waco
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Re: Power & HDD activity LED sharing?

Thu Sep 15, 2011 7:48 am

I'm not too sure how well the mobo will cope with being back-fed power when one of the outputs (say, the power LED) is on and the other (HDD) is off. Maybe someone else can chime in on that?

I imagine it wouldn't be too hard to install a second LED for dim power and point both LEDs at whatever cover/diffracter/whathaveyou is in place on the case already (which looks like a small piece of plastic).
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FubbHead
Grand Gerbil Poohbah
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Location: Borås, Sweden

Re: Power & HDD activity LED sharing?

Thu Sep 15, 2011 8:14 am

Hmm. True. Perhaps a diode on the hdd output will suffice to prevent this? Or maybe this will end up being some kind of transistor abomination? :)
Amiga 1200, 68020@28MHz, 4MB+2MB RAM, Conner 80MB harddrive
 
DLHM
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Re: Power & HDD activity LED sharing?

Thu Sep 15, 2011 8:37 am

I just did this to test it and it works.

1 Cut the both positive and negative wires coming from both the power and the HDD leds.

2 Tie all the positives together.
3 The negative from the power will run through a 220ohm resister.. "Red Red Brown" to the negative onthe LED.
4 The negative from the HDD runs to the negative on the LED.

This will knock the led to about 20% brightness ( at least on mine, I have a blue LED) the led will be on constantly but will pulsate with the HDD.

I don't think this should cause any problems, your only dealing with ~.015 watts of dissapation.

edit.. actually .018 watts
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FubbHead
Grand Gerbil Poohbah
Topic Author
Posts: 3482
Joined: Mon Apr 08, 2002 9:04 pm
Location: Borås, Sweden

Re: Power & HDD activity LED sharing?

Thu Sep 15, 2011 4:20 pm

Ah, nice. Gonna try this as well. Thanks!
Amiga 1200, 68020@28MHz, 4MB+2MB RAM, Conner 80MB harddrive

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