More of a case mod topic

[M-80]

I remember reading a topic here about how to power something that requires more power than 5V directly from the power supply, but making a bypass circuit board that would only activate that power source when a 5V power source was activated. I think it had something to do with a lighted button where the light was pulling more power than the PS/2 port would generate.

Well, what I'm trying to do is mount a LED on a rotating motor so I can mount that underneith a panel with 6 holes in a circle. So whenever there was hard drive activity the motor turned and the light would go on. The effect I want is a spinning light passing behind holes in the computer's case to give the effect like the hard drive was turning and the HD activity LED would symbolize that. Technical symantics aside, some of my friends said a motor would pull more power then the motherboard's hard drive activity LED pins would provide. So I thought of getting power dirrectly from the PSU. But then I thought that would make the motor turn constantlyand I only want the motor turning when there's hard drive activity. Then I thought of a post here that delt with that kind of bypass or control mechanism for a lighted button. Anybody know what it is I'm talking about?

I thought that would be a cool case mod rather than your plain old static activity LED. And perhaps that would have some sort of application to arcade controls. Maybe a cabinet mod of some sort or maybe a fancy button with a spinning LED in it.

Here's another idea. Maybe a sequenced LED array would work. I'm not sure of the technical term though. Like 6 LEDs that flashed in sequence but in a circle.

[rdagger]

I would go with the several LED approach.  It is a relatively easy circuit.  It could be done with a single AVR chip and a few resistors and capacitors which you could buy for about 3 dollars.  It could also be done using a 555 timer and a counter.  If you wanted to get fancy you could add a dimming effect for a smoother transistion between LED's.

If you go with the motor, it seems like it would be tricky to power the LED.

[Dak-ak]

Well, what I'm trying to do is mount a LED on a rotating motor so I can mount that underneith a panel with 6 holes in a circle. So whenever there was hard drive activity the motor turned and the light would go on.

Thats quite the job there.  rdagger has a good point, the original idea is pretty easy: "how do i power a dc motor with a pin that can only sink several milliamps?"... two options come to mind: either use a darlington array (a ULN2003 chip is a very simple way to do this) and use power from the power supply, or use a relay (electrically operated switch) HOWEVER, that only gets the motor spinning...

how do you plan on getting power to the led?  If you just run wires, you'll find that they get very tied up, very fast.  what you would end up having to do is make some sort of collar for the motor, solder onto the brushs, and run leads up the the LED... possible, but not easy...

I did osmething similiar with big fiberoptic strands (very thick) that i ran from blades on a pc fan to below the center, and mounted several bright LEDs underneath... the fan spun, and had lights in it, but the leds stayed put.  An idea that might work for your application...

Perhaps you'll want to consider the LED array

The way i would do it is to use a timer circuit like the 74LS.  You just buy one of these for each pair of LEDs... a resistor/capaciter pair for each as a timing... the LEDs, a current limiting resister for each LED, and I think you'll need a voltage divider LED for the Vcc (probably want to step 12 volts to ~7).  Shouldn't be a very expensive projet, I think.  Wire them all up for trailing edge triggering (except the first).  

Your HDD LED header goes high... so the first timer is triggered... it goes high for a while, then goes low... as it drops low, the next one goes high, and so on.

Hum.  Sounds so easy, I might wire one up myself... Good idea

Thinking about building a crappy little case from scratch for a server, this might be a cool little addition.

[M-80]

Yeah. I've wanted a visual representation (even if it isn't very accurate) of my HD/OD being accessed and I wanted more than a static activity light. I thought maybe I could use the Thermaltake light on the front of my case to throb off and on whenever there was drive activity, but apparently all it is made for is to shine and look pretty. Heh. That trailing LED concept sounds like a good idea to deal with the artificial stop/go effect of just having individual LEDs blink in turn. It would definitely make it look more natural (as natural as computers can get. Ha!). I don't think I'll do it with the case I have, but I'm going to make a new case from scratch because I'm starting to think of putting together an Athlon 64 system sometime within the next year or so and I thought what would be a good christening than a homemade case mod done from scratch.

[mr.Curmudgeon]

Hum.  Sounds so easy, I might wire one up myself... Good idea

Be sure to post it here   , sounds interesting and I'd love to see how you get it to work!