Pimps,
I have a new case mod cooking, but there are a couple of places where the work to be done is way out of my depth. One of these places is in some LED work I would like to do. So far all of the things I've done with LEDs are to 1. buy them and 2. plug in the molex.

There are two things I want to do with the upcoming mod. The first is to simply have a row of LEDs spaced out, which will be used to illuminate some items above them (sorry I can't be more specific. I don't know for sure what the illuminated items will be, nor do I want to give it all away just yet). The second thing I'd like to do, which is more complicated, is to make a bank (maybe 5x7 or so) of LEDs that randomly flash, sort of like what you would see on a big mainframe in an old Sci-Fi movie.

The problem is that I don't know thing one about wiring up anything like this. If anyone can help with a very noobish explanation, I'd really appreciate it. For example, do you connect the LEDs in serial? How many LEDs can I run off of one Molex connector? To get them to randomly flash, will I need some sort of controller? This will be the first time I've ever gone from loose LEDs to finished product, so even the extreme basics would be helpful.

Thanks in advance for the help.

::EDIT:: Found Jonny English's guide, which helps a lot with the basics.
http://forums.pcapex.com/showthread.php?t=12340

I'm still not sure what it would take to make a larger array, or how to get them to flicker.

YOu can run many LEDs off one molex connector, they run on 5V (but arent that bright)7v, and 12V. Just make sure you use the proper resistance. As a rule of thumb I usualy use 220Ohms to 270Ohms for the resistor on each LED.

To make them flash there are many circuits you can use. One kind uses a 555 Timer to provide pulses. The other is called a fading circuit. Now depeding on your knowledge these projects can be hard or easy. But all you need to know is the pin outs.

http://ourworld.compuserve.com/homep...5.htm#eyes.gif

Look for the fading red eyes circuit.

Run LEDs in parallel with the voltage source, each with its own resistor.

EDIT: The 555 timer circuit will only flash the LEDs ON or OFF. The fading light circuit looks alot cooler with the correct flash rate. Heres a short movie of one I made.

http://members.fesgaming.com/kaiba/i...boredmovie.MPG

That does look pretty nice, but it's not quite what I was going for. I think I need to go back to basic physics. I'm a PhD biochemistry student, and all of the circuit diagrams look like heiroglyphics

Heh Thats why Im here bud..

Ok. See those triangle things, those are op amps. They can do many things but right now they are generating a wave (a triangle wave if you will) the second opamp just shapes it up some more. See the thing that are labled 47k, 100k and 100? Those are resistors, they resist current (easy eh ) See the thing labled 22uf? Thats called a capacitor. A capcitor hold a charge. In this case its being used for timimg. Increase capactiance (ie make it bigger, say increase it to 100uF ) and the timing will get longer (meaning it will take longer...) decrease it and it will flash faster (timing will get shorter) See the thing labled 2N3904? Thats calleda transistor. Right now its being used to provide current for the LED(S) since the opamps will not have enough current to drive them (and to keep the signal clean from loading effect)

woo! I think thats its..VCC is +(+9 works on 12V too), ground is negative..

Of course some of those components can do more than those mentioned.

EDIT: So wait, you dont want the fading LEDs thing? Or do you want them to blink..I really didnt get what you meant by flicker..

I want something like this, just not as big:


where the lights flicker on and off... haven't you seen old B-grade Sci-Fi, or are you too busy watching anime and schooling n00bs on electrical diagrams

::EDIT to be clear, they shouldn't blink all at the same time. I'd like each one to be intermittent...
I'm starting to think I should just find a panel like the one I want and transplant it....

Quote: Originally Posted by Bionic I want something like this, just not as big: where the lights flicker on and off... haven't you seen old B-grade Sci-Fi, or are you too busy watching anime and schooling n00bs on electrical diagrams

hmm Lemme look around. I need more of a description. Ive seen that before... do they flick on and off sequentually? Like one after the other?

Ok how about like this:


EDIT: you can put the LEDs in a random order, meaning keep them connected the same way, but have them in a random order physically..

Quote: Originally Posted by Bionic I want something like this, just not as big: where the lights flicker on and off... haven't you seen old B-grade Sci-Fi, or are you too busy watching anime and schooling n00bs on electrical diagrams ::EDIT to be clear, they shouldn't blink all at the same time. I'd like each one to be intermittent... I'm starting to think I should just find a panel like the one I want and transplant it....

I'm not going to attempt to outdo Nerdz excellent description!!!! But I got interested in this, (I may need one someday) and saw this up on the web.
http://www.kpsec.freeuk.com/projects/random.htm
This will give you a 8 LED random sequence flasher. It's shows as 9 volt battery device but I'm sure that can be adapted. Or it may work as is. Build two and you've got 16 LEDs . Electronic diagrams is one of my weaknesses, but I can understand this one.
Nerdz, thanks for showing me your diagram....

Something like this (I hope the animation works):

Attached Thumbnails

 

I know the effect you mean, Bionic. The movie "Wargames" must have some in it, with all those 1980's "supercomputers".

If you really want to know how and get good at circuit electronics, more power to ya. But if you're more interested in the result than the experience, you may be able to pick up some products that'll do what you want for pretty cheap.

Here's one product you might be able to use. For $5.50, it includes 160 LED's that flash in different patterns (includes pattern generator with 24 modes). Runs off 5V. You might be able to just put those bars side-by-side to get the array look. May or may not be exactly what you're looking for, but it's hard to beat the price.

3 bars pictured of the 20-bar assembly:

Quote: Originally Posted by prime-evil I'm not going to attempt to outdo Nerdz excellent description!!!! But I got interested in this, (I may need one someday) and saw this up on the web. http://www.kpsec.freeuk.com/projects/random.htm This will give you a 8 LED random sequence flasher. It's shows as 9 volt battery device but I'm sure that can be adapted. Or it may work as is. Build two and you've got 16 LEDs . Electronic diagrams is one of my weaknesses, but I can understand this one. Nerdz, thanks for showing me your diagram....

Yes it can be made to work on 12V. It a CMOS Chip

*WARNING*-Since it is CMOS, MAKE SURE you are grounded or else you WILL fry the chip. Observe the same procautions as if this were a mobo.

Quote: Originally Posted by Bionic Something like this (I hope the animation works):

Thats called a binary Counter.

Quote: Originally Posted by FunkyFresh Basically, he's talking about an array of LED's, sorta like the picture below. But instead of them all being lit up, just have 3-5 randomly lit up at once for about a half-second, then move on to another random 3-5 and so on. If you really want to know how and get good at circuit electronics, more power to ya. But if you're more interested in the result than the experience, you may be able to pick up some products that'll do what you want for pretty cheap.

Yes, that's it. I am having trouble expressing myself today. While I think that knowing electrical circuits would be a nice skill, I am definitely not against buying something that is partially assembled already. I guess what I was hoping is that someone would know of a controller board that would take care of the flashing sequence, which I could wire the LEDs to.

Kits:http://www.elexp.com/kit-all.htm
More Kits:http://jameco.com/webapp/wcs/stores/...ategoryId=7030

Dont worry about it...Could have been me to misinterrepting your post. ive been doing that alot lately..

I did a major edit of my post above, since I'm a major slowpoke in typing replies (everyone replied while I was still typing).

Anyway, for the other question you had (a string of LED's), you might be able to use something from Performance PC's lightstrips selection. Other places may have these cheaper, but they're all in one place here. Or you might be able to use an LED cluster.

EDIT: Found it! Here's a poor-quality screenshot of the "WOPR" supercomputer in the movie "Wargames". Those LED displays would change random patterns every half-second or so.

Thanks to both of you. FF, those products look pretty interesting. I might have to buy a couple just to check them out. I have a feeling that I'll have to some basic LED wiring anyway, but I think I'll be able to figure it out as I go. LEDs are pretty cheap anyway