First off, WOW at your project... Now you are making me want to install that into my bedroom's ceiling!
To get back to business... I do agree with you that I do need to run SOME of the LEDs in series. One of the problems I have with this, is that it *might* conflict with the automation of the runway. I don't know how close you followed Bruce Willace in the Die Hard trilogy, but in one of them, he is running arround saving planes at a airport. At some stage, the terrorists take over the runways and shut them down. Did you notice the effect of HOW the runway shuts down? It is one MASSIVE Chasing LED sequence, running from the start to the end of the runway, switching of everything in parrallel. When the runway is switched on again, or reversed, the chasing effect is also reversed. This isn't going to look good - I'll draw some gifs later, but you are looking at something like this:
[pre]
1 X XX X
2 X XX X
3 X XX X
4 X XX X
5 X XX X
6 X XX X
7 X XX X
8 X XX X
9 X XX X
10 X XX X
[/pre]
Let's take the above as a small section of the middle part of the runway (the simplist part because the lights serve no other function than to be on or off.
Should the aircraft be approaching from row 10 to 1, the ENTIRE row 10 is switched of up to 1. Should the runway be reversed, the ENTIRE row 10 to 1 is switched of, and it is switched back on from row 1 to 10 (in a completely reversed sequence - the entry lights / signal lights further than row 10, now sits on the other side, further than row 1). Now, that's simple in that I can connect a entire row in series for example, but the problem comes in at the fact that towards the end of the runways (past rows 1 and 10) - the lighting gets ALLOT more complicated, and I can't simply connect a row in parrallel - unfortunately about 30 to 40% of the LEDs are situated PAST rows 1 and 10 on a active runway.
In regards to controlling the system, I am busy designing a computer based controller system that will used the printer port to control over 2048 triggers (+5V pulses) individually. This will be FAR more than I need, and I am also sure that allot of pics will be involved (something I have zero experience with so far). I was hoping to post more about this at a bit of a later stage and try to make this a "joint" project where more than one person is involved in the designing of the circuits. Due to size, the boards needs to be broken up into sections in any case.
This may be a bit of a silly question, and I admit I am asking this now without doing any research into it... What will be good values here? What will be the ideal amount of leds in series, at what supply voltage, and what is generally good values for current limiting resistors?? 100Ohm? Are there perhaps any good calculaters out there that I can use? Obviously, I won't be able to ALWAYS put 20 LEDs in series. In some cases, I may manage 20, in others I may only manage 5. Obviously, the supply voltage can't be the same. I am talking under correction, but with the LM7805's during my testing, I ran about 10 LEDs with 5V1A before they started fading...
The entire airport will be controlled by a Delphi appliction - strangly enough, the application is REMARKABLY simply to program and operate - definately not even a thought in my mind right now. The biggest problem is getting the circuit correct to allow for maximum capabilities in regards to turning LEDs (or arrays of LEDs) on or off (ala automation).
The question to ask now however, is how many LEDs in series are REQUIRED to bring the voltage down to a acceptable level to stop the LEDs from burning out and poping. I honestly doubt that there will be allot of places where I can manage to get 20 LEDs in series. Frankly speaking, are you even able to operate a "chasing" effect with LEDs in series - whilst NOT affecting the brightness of the LEDs during "normal" operation. I am aware that I can generate a "chasing" effect via the use of resistors, but these would also affect the brightness (LED1 definately won't be the same brightness as LED100 at the other side of the runway).
And wires.... Those are definately DEFINATELY
DEFINATELY out of the question. I'll more than likely stick to ribbon cable for signalling and use some sort of sliding slot to connect multiple boards together SILs or something to that effect... That's one mess I most definately do not need... hehe
Again, thanks for all the feedback so far. I'm sure we're going to discuss this ALLOT in the future... I already spend hours just getting the scales right and the alignment of the LEDs to get the right amounts... If there is a interest, I'd definately appreciate some people coming aboard to help in the design and construction of the proto types... I reckon airports / meuseums, and allot of other places will definately be interested to have decent automated models of their airports built for them. (I hope) Just think of the educational benefits *g*
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Chris