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[obsoleet]

I Have 5v 5mm LED's and the case came with 3mm 3.2v LED's, is there anyway i can boost the voltage to the LED so it will light ? (and inverter circut or something) the 5v's won't even light up at anything below 4.5v.

[I LOVE ED]

You would need something to amplify your LEDs so you would get like 5v from a molex.

This is a circuit made by Linear.  The 4N22 is an Optoisolator, that would protect your HDD mobo header.  R is the limiting resistor for the LEDs.  I haven't tried this circuit yet but I will for my next project.  Now the limiting resistor can be computed using the standard LED resistor calculation (see Brutal's site) but I have also seen a formula that also involves the number of LEDs to be used so I'm unsure.

http://www.geocities.com/_x24/HDD_LEDs.txt">

Here's the formula for R

R = (Vs-0.2-Vf)/(n*If)

where
 Vs: Supply Voltage
 Vf: Forward/Operating Voltage of the LED
 If: Current rating of the LED (usually 20mA, use 0.02 in the formula)
 n: the number of LEDs connected in parallel

the 0.2 is a loss of voltage in the optoisolator (as Linear said) so he put it there to be on the safe side.  About the number of LEDs, I'm not sure until how many you can place in that cicuit.  I'll let you know when I do.

_________________
"...I told you I'd shoot! But you didn't believe me! Why didn't you believe me?!"
   - Stinky Wizzleteats

Happy Happy Joy joy song"

[GideonX]

On 2002-05-17 20:12, Hubstack wrote:
Gid,
    Why didn't you use the 3mm led in your speakers. Why go through the trouble to sand it down to make it fit.

Just wondering.

Oh they make the square leds in blu for your floppy.

All n all u did a good job. Connections could have been better. Not to happy with the floppy drive.

Hubstack

i had about 12 5mm leds, and no 3mm didn't feel like plopping down some more  cash to have them deliver just a few 3mms.

[The Duke]

To any one who doesn't know and LED is a diode, hint the name Light Emiting Diode, so make sure that the polarity is correct or you will get nada. Just thought I would throw that out there. Oh and X24, that optoisolator is a good idea.

[merlinicorpus]

dur!

[viridius]

To follow up, "diode" means that it will short when it conducts.  I know you are all sick of hearing this, but I thought it had to be reiterated.

_________________
"...and suddenly it hurt so much I found myself laughing."-R.A. Heinlein

[The Duke]

The only reason I posted that was because I'm sure that some newbie will wonder by this site and may not even have a clue what LED means, much less what it is. Just 'cause you're an experinced case modder doesn't mean everyone is. Think about the new guy getting into it and when you first started out. Every little bit of info we can pass on helps. That's the only reason I posted that.

[I LOVE ED]

Thanks Duke.  I might get the credit for posting that circuit but give credit to Linear for the circuit itself.  And to add to the LED info, in schematic, it is denoted by a Diode symbol with some arrows pointing somewhere to show it emits something.

[The Duke]

Here is what I know about Optoisolators. It's pretty limited, so if I get something wrong, please correct me. A and K are your leads off your LED in side your Optoisolator. Usually on pins 2 and 3. I say usually. B will be your ground and is pin 5. C in your Voltage of course and is pin 8. E will be you output and will be either pin 6 or 7, I can't remember. The transisitor is actually a Photo-transistor and is light sensitive. When the current is passed thru A and K, the LED emits light and the Photo-transistor is saturated, causing a complete circuit. When the LED current is lost the saturation is lost and so is the circuit thru the Photo-transistor. The thirs leg on the transistor is photo sensitive, that's why it saturates when the LED is on. This is for a typical 8 pin DC optoisolator. I hope this helps and if any of it is wrong, please correct it so everyone will know. Thanks.

[Mat128]

My Floppy drive led is smaller than 1mm.... what can i do??? My tower is a Dell Optiplex GX110 non-modded... (i can make a screenshot but its will be low quality because of my old webcam)

Thanks, Mat128