anyone know anything about LEDs? and how to set up a series of LEDs??

[shocksyde]

i've got some funky Mod ideas for my case and was wondering if anyone here knows how to set up series of LEDs?? and maybe where i could get the necessary supplies??

shock

[Jeff7]

I've got a bagillion LEDs here; I can sell you a few cheap if you'd like - 10 cents each plus 55 cents to ship them. (Or you can pay about $2 apiece for them at Radio Shack. http://sysopt.earthweb.com/forum/smile.gif)
To connect them in series, just connect them in series like they were capacitors - positive of one to negative of another, and so on. Only thing is, they run on about 2.5v; closest a computer comes to that is 3.3v. Maybe Virtual Hideout (http://www.virtualhideout.net/) has something in there on where to connect LEDs. I think there might be some info in the Fanbus section.

[Graham]

Shocksyde
LED's are easy to use, like jeff says they can work on anything from about 1.5v to over 3v, the good thing is that if you connect them in series (anode to cathode to andode etc ( in a long chain))and they are all the same type, then the votage across each one can be adjusted by adding or removing LED's in the chain.
For example if you have a 12v supply and the LED's require 1.5v each (most common), you will need to use 12/1.5 LED's = 8. If you need to use less then you will have to add a resistor to limit the current.
Connecting in parallel is more complex as you have to have (in effect) a supply of the correct voltage or use a current limiting resistor (simple ohms law to get the value.
Be aware that LED's are polarity sensitive (they have a pos and neg).
You might find that you could use one of the high level brake lights sold for cars, some of them use LED's, and are set for 12v obviously.

G

[shocksyde]

well i was thinking about using around 50, maybe a little less. also, they need to be blue, and very bright. is there a way to hook them up so that they could be plugged into an outlet? or is there a way to tap into the power supply?

your suggestion for using 8 to equal 12 volts wouldnt work for me cause i'm looking to use 50...got any other suggestions???

shock

[Graham]

You could wire up a series chain of 50 across the mains but I wouldn't advise it, too dangerous. Just for info if you are using blue LED's they require a higher voltage, about 3v, so then if you have a 120v supply (I assume you are in the states) you would need 120/3=40 LED's. They are polarity sensitive as I said, you would have to add a diode to half wave rectify the supply. Blue Led's are much more expensive than the common red ones.
You could still use a 12v supply, stings of three, each connected in pll, i.e.

-*--*--*-
| |
-*--*--*-
| |
-*--*--*-
| |

12v

Where -*- is an LED.

If each draws 30mA from the supply, then you would take 40*0.03 A =1.2A, this may be too much for the psu if you are running the PC as well.
Just possible you could substitute LED's for the lamps in a string of Christmas lights, that would make it safer. Be sure that there are at least 40 bulbs (for a 120v supply).

Getting complex aint it ??

be carefull

G
P.S. Bet the diagram doesn't come out right !

[SoopaStar]

http://home.wanadoo.nl/digistorm/casemod/

I want to do something similar to this guy's mod on the inside. (Except I will be 'hiding' the LED so that it is not 100% visable).
What is a good place to buy LED's? (looking for blue, green, maybe red). Also, I found some sites that had dual-color LED's...how could I utilize these? I have a nifty idea that I just got from the Xmas light suggestion! So those would just be plug n play then?

Paul

[shocksyde]

actually, my initial idea included a string of xmas lights! hehe. great minds think alike. however, like always, i did no research and bought a string of 140...hehe. i have found that the common xmas light bulb and base is too long to fit in my pc. it's hard to explain but i plan to create a symbol in the side of my case with either xmas lights or blue LEDs. and it's going to be on the motherboard side, so i dont have much room. anyone seen really short xmas lights?

also, if i were to end up using 40 or so LEDs, would that be REALLY expensive????

shock

[Richard_Cranium72]

While we have a gathering of brilliant minds talking LED's..

I have a project in the works for the DNR.

I have some HP High Power IR LED's

375mw @20% duty cycle, THAT's the problem, are there any off-shelf drivers for such a thing. These are 5v 880 nanometer with a 17 degree beam.
Long distance IR's for b/w illumination.

OR, ANY ir light source will be considered if anyone can come up with a idea..

thanks
DrVette

[shocksyde]

hey, someone check out this little faq type page. http://www.misty.com/people/don/ledd.html

at the bottom it gives a small blurb about putting LEDs in a series. it says that you could as long as the power supply is 20% stronger than the total LED Voltage intake would be (to be safe). so, could i use a 230 volt power supply from another comp to power my series???

shock

[Graham]

DrVette,
Is that the total power consumption? A 555 timer will supply about that (cant remember the exact value), simple circuit to vary duty cycle. If you need higher current a single transistor can take you much higher. I assume that you dont want to use them at a very high frequency.
What is DNR, and is b/w black & white ?

G

[Roy]

shock ~ I think you are confusing Power (W) and Voltage (V).

Using the water hose analogy, Voltage is like pressure, it can be there when the valve is closed. Current/Amperage (A) is like flow ~ gallons per minute, for example. A small hose gives you less flow for the same pressure. Power/Wattage (W) is the multiple of Voltage times Amperage. You get more power from a bigger hose, given the same pressure.

There are tiny incandescent (filament) lights that would do the job, if necessary you could dye them blue. They could be wired in a series/parallel arrangement to work off the 12V (drive motor) section of your supply. They will last allmost forever if you run them 10% below their rated voltage. Go to Radio Shack, All Electronics or Newark to see what's available. They all have web sites.


[This message has been edited by Roy (edited 11-16-2000).]

[shocksyde]

i want to use LEDs because they're so bright...i'm going for the blinding effect here.

still looking for some help as to how to get this started!!!

shock

[SoopaStar]

http://www.mpja.com/allpict.asp?dept=116

They have blue ones. NOT cheap tho.

Paul

[Jeff7]

That's a lot of LEDs; normally, that wouldn't be too expensive, but blue LEDs can be hard to come by. Try Electronic Goldmine (http://www.goldmine-elec.com) . They have a decent LED selection.

[SoopaStar]

Another (http://www.radioshack.com/category.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F010%5F012%5F002%5F000&Page=1)

another (http://bgm.bgmicro.com/)

I just did a search for "electronics LED motor wire solder" on the MSN search engine. Google.com would be another good one to search on.

Paul

[Roy]

Not all LEDs are BRIGHT. High intensity LEDs (of any color) are more expensive. Blue LEDs have been around the shortest time and are MUCH more expensive because the technology is newer. Expect to pay a couple of bucks each. The 3900mcd (millicandellas) at MPJA are $2.89 each in your quantity, and likely are as bright as you might want.

In general, to get a "blinding" effect, look for ones with the narrowest angle of disbursion. That way the available light is more focused on the viewer. LEDtronics (http://datasheets.led.net/Pages/470nm_super_blue/92d.htm) has some 15 degree 2000mcd units, they don't show prices on that page. When you have selected the type it will be easier to figure out how best to power them. If you like, email me the information and I will send you a diagram of how to wire them up.

On a happy note, since you are using only about 40 of them, there will be no problem using the existing supply in your system.

[This message has been edited by Roy (edited 11-16-2000).]

[shocksyde]

roy, did you get my email?

shock

[tonym]

shocksyde,

If you MUST (!) use strings of LED during your playtime (!!), then I suggest that you get a 48V power supply (you can get one from Jameco -- <A HREF="http://www.jameco.com" TARGET=_blank>www.jameco.com</A> -- REAL cheap) and set up strings of 20 LEDS with a series resistor in each. The limiting factor in how many strings you can put in parallel across the 48V source will be it's output current (power) rating. And that's a matter of the dough you're willing to spend!

If you use 48V, then you don't have to use a whole bunch of strings of LEDS to do what you want to do (and you'll use fewer resistors too!). It's a good compromise supply voltage to use.

Good luck/have fun!!

[Also, in addition to Roy's vendor, you can get LEDS of all flavors from Digikey -- www.digikey.com (http://www.digikey.com) . The Panasonic LEDs are quite bright/efficient, but they're not FREE!]

Tony

[This message has been edited by tonym (edited 11-19-2000).]