LED in a painting help?

[covertmesa]

Hi people, i'm really new to this and was wondering if anyone could provide a simple, basic, schematic to hook up 3 led's to a 9v battery with a power switch? I've been searching on google and I guess i'm not typing in the right things, I keep getting really advanced results.
I wan't to put the leds in a painting i'm working on for someone.
Thanks in advance.

 

[covertmesa]

It may also help to know that I have some knowledge in circuits and electronics. I know that i'll need to use resistors to lower the voltage to each colored light according to the specs OF that color and I have a decent understanding of building circuits and reading the schematics. I'm just having a hard time understanding the more advanced electronics speak on the sites i've found, and most are for things that are not exactly what i'm looking for.

 

[Marks256]

No offence to your idea, but i have seen this done before. It looks like crap. That is my opinion, but there were a few cool ones. Anyways you will need a 300 ohm resistor.

 

[RODALCO]

Better use a dc powersupply.
Depending upon the type of LED you want to use your 9 Volt battery won't last long if you run the LED's at 20 mA..

3 leds in series would be your best bet and series resistor perhaps from the battery for a couple of hours at say 5 mA.

 

[akg]

Hi people, i'm really new to this and was wondering if anyone could provide a simple, basic, schematic to hook up 3 led's to a 9v battery with a power switch? I've been searching on google and I guess i'm not typing in the right things, I keep getting really advanced results.
I wan't to put the leds in a painting i'm working on for someone.
Thanks in advance.

3 leds in series ..??

--batt[b]+[/b]-----R---->|-->|-->|--SW---|

R ~ 270 Ohm , , sw is switch , >| forms the led

 

[mramos1]

You are still gonna go through a lot of batteries.

 

[HiTech]

Maybe his painting is something of buildings or street lights that would look unique from it or similar. Hey at least he's not trying to use hundreds to thousands of them to do up a New York City skiyline!! I saw one of those cheesy artworks in a Chinese restaurant and two of them in an Indian restaurant. The Indian restaurant had sequential flashing leds outlining the beards of these two famous gurus or mohatmas, whatever. It looked very cheesy!

Now instead of leds you could simply use a single bright white led, a lithium battery and run some fiber optic cables to the necessary points in the painting. It will operate for a long time.

 

[Marks256]

I have wanted to use fiber optics before. How do you work with it? I am sure it isn't like stripping a wire. May i ask what the painting is?

 

[mudassir_semiconductor]

battery+------res-----+of led ---- -ve of led ------to -ve of batt

 

[Marks256]

I have attached a REAL diagram of this. I tested it, and it works great!

 

[StopGo]

Those LED's are in parallel, not series.

I'm sure it does work, but from a design point of view whats the best way and why?

Series or parallel LED's ?

-edit can't spell parallel

 

[Marks256]

Yeah, i know that it is in parallel. I too would like to know, parallel or series? Series would use less material (wire, solder), but parallel looks cooler. If you would like, i could redraw it?

 

[Nigel Goodwin]

Those LED's are in paralell, not series.

I'm sure it does work, but from a design point of view whats the best way and why?

Series or paralell LED's ?

You should NEVER parallel LED's - as they won't share the current equally. If you must put them in parallel, you need to give each it's own series resistor.

 

[StopGo]

Ok so manufacturing differences result in slightly different voltage drops at a given current. In parallel LED's the LED with the lowest voltage drop clamps the other LED's to the same voltage drop, no doubt there will be a range of different currents flowing through each LED.

In Series, the same current flows through each LED but the voltage drops can be different.

Ok so power output by each LED is V*I

Parallel LEDs : constant V, variable I
Series LEDs : constant I, variable V

Is one really better than the other ? Why ?

 

[Nigel Goodwin]

Is one really better than the other ? Why ?

Yes, because series works, and parallel doesn't! (it blows the LED's), even if it works initially they will tend to have a far shorter lifespan - it's bad practice, DON'T DO IT! - don't even THINK about doing it!.

 

[Marks256]

Ok, here are the changes.

 

[HiTech]

Some of are still waiting to learn of what the painting is of, that you are cheesing up!

 

[Marks256]

Yes, do tell! (probably putting RED LEDs in the Mona Lisa!)

 

[audioguru]

The current is much lower with the LEDs in series. Re-calculate the value of the current-limiting resistor.

 

[covertmesa]

I'll post a picture of it when i'm done. I'm not into hokey art though, and i'd never add led's to anything if it wasn't completely off the wall. It's not just a painting either, I work in mixed media.
Thanks to whoever mentioned the fiber optic idea. I hadn't even thought of that, I don't know how that'll go over with this idea, but i'll toy around with it.