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Smiley
03-29-2008, 07:33 PM
First, a pop-quiz.

Please tell me what is wrong with this picture:

http://img134.imageshack.us/img134/3747/ledgr0.jpg

Anything missing? Anything out of order?

Infoamtek
03-29-2008, 07:54 PM
For one, I'd say the limiting resistor.

Smiley
03-29-2008, 08:05 PM
I see.....

Anything else?

Infoamtek
03-29-2008, 11:40 PM
It's hard to tell from the picture, but the leads may be reversed. Did anyone check to see if it worked before soldering it together? Also did anyone check to see if the diode was rated for 9 volts?

Smiley
03-30-2008, 09:01 PM
When it comes to this kind of material, I'll admit I'm poorly educated. What you see is a "trail run" of miniature lighting I plan on installing into a prop. When I was working on it, the diode did blip some light at first. But that is as far as I have gotten. I know it's not the battery nor bad wires (I've tried several of them). Perhaps I purchased a bad diode? I don't have instructions for this kind of thing, but pictures of something very similar; so I follow those.

What I want to create is a set of about 5 to 8 LED lights (10mm) running off of a battery source.

scareshack
03-31-2008, 05:42 AM
heres a few links that may help ya some.
http://wolfstone.halloweenhost.com/HalloweenTech/anemak_MakingLEDEyes.html#SimpleLEDEyes

http://led.linear1.org/category/led-basics/

Smiley
03-31-2008, 07:28 AM
Ah, thank you.

naberhoodhaunts
03-31-2008, 04:43 PM
It seems to me that most leds are 3 volt you need a reducer in between. i'm not a pro at this but that would be my guess.

Gore Galore
03-31-2008, 06:36 PM
John is right,
the limiting resistor is missing.
And you need to make sure the red lead is attached to the pin that is connected to the flag in the led (HOT).
You can also use one battery to run 2 leds off of with no problem.

mindtumor
04-01-2008, 02:25 PM
If it blipped and then quit working you probably blew the LED. LED's hooked up in that manner are basically just a short a across your power source.

imax
04-01-2008, 02:36 PM
Yeah, the 'blip' is a dead- (ha ha, sorry for the pun) giveaway. You *murdered* a LED. Go get a resistor, and a new LED and try again. Killer.

-- I

Smiley
04-01-2008, 05:43 PM
Yeah, the 'blip' is a dead- (ha ha, sorry for the pun) giveaway. You *murdered* a LED. Killer.

Hopefully it didn't have any family. :)



And you need to make sure the red lead is attached to the pin that is connected to the flag in the led (HOT).

Pin? Flag? Whosajigawha?

Scottzilla
04-01-2008, 07:24 PM
I think the "flag" Gore Galore is referring to how when you look inside the LED one lead goes to a larger piece of metal (the one with the die and the reflector cup) than the other one. GG said hook the red wire to the "flag" pin but I've run into more negative "flag" pins than positive. The truth is there isn't really a standard for which pin gets the die so I usually just find the polarity by hooking it up and trying it.

Of course, always make sure to use your current-limiting resistor.

...unless that is part of your haunt. Killing LEDs in front of a live audience might be too graphic for some people. You should post a warning outside in your queue line.

Smiley
04-01-2008, 08:01 PM
Okay, okay. What if.....

I hook up eight 5mm LEDs (20mA each/forward current of 17.6 total) to a 18volt battery source and use a 22 ohm 1/8W resistor? How's that?

Infoamtek
04-01-2008, 08:43 PM
In series of parallel? This is an important question.

Smiley
04-01-2008, 09:27 PM
Umm....parallel circuit.

Infoamtek
04-01-2008, 11:37 PM
Young man, I suggest you take some basic night classes in electricity and electronics. Otherwise, you are going to be dangerous around components and circuits.

( In parallel, 18 volts is going to burn out a lot of LEDs)

Smiley
04-01-2008, 11:53 PM
Bah. Forget it. I'll just buy a pre-assembled set.

Scottzilla
04-02-2008, 12:08 AM
Ideally you would have a separate resistor for each LED. 9v will drive them all just fine, just make sure to choose the appropriate value resistors (if you post the voltage rating of your LEDs I can help you with that).

Also note that since you are drawing 160ma total you will probably get just shy of 2 hours out of a 9v battery. You may want to use a wall-wart instead.

Anyway, here's a quick schematic I drew of how you can hook up your 8 LEDs:

Smiley
04-02-2008, 12:21 AM
Ideally you would have a separate resistor for each LED. 9v will drive them all just fine, just make sure to choose the appropriate value resistors (if you post the voltage rating of your LEDs I can help you with that).



The LED's I plan on using are these: http://monsterguts.com/lighting-strobes-led-39-s/amber-led-10-pack-/prod_115.html


Anyway, here's a quick schematic I drew of how you can hook up your 8 LEDs

Ah, yes! Pictorial instructions! Now this I understand.


Also note that since you are drawing 160ma total you will probably get just shy of 2 hours out of a 9v battery.

Two hours of run time, eh? :/

Scottzilla
04-02-2008, 01:31 AM
Okay, so here's what we know about your LEDs:
Forward Current - 20mA
Forward Voltage - 2.2

If you use a 9v power supply or battery and the LEDs are dropping 2.2v of that, then it means we need the resistor to drop 6.8v (9-2.2). We now know the voltage across the resistor and the current going through it (20ma or .02 amps, same as the LEDs), so we can use Ohm's law.

6.8v / .02A = 340 ohms

The next-highest standard value resistor is 390 ohms, so that's what you'd want to use (get 1/4 watt; 1/8 watt isn't big enough).

Scottzilla
04-02-2008, 01:36 AM
BTW: technically you could power your 8 LEDs with fewer resistors, but this way you can have as few or as many LED/resistor pairs as you want without having to recalculate anything.

mindtumor
04-02-2008, 02:57 PM
You could buy a power supply from minispotlight, that way you aren't draining batteries. It seems to me they were like $15.00 or so. That just covers your source though, you still need them resistors.

Smiley
04-11-2008, 05:24 PM
http://img80.imageshack.us/img80/3064/prototypeeu1.jpg


Ha! Who needs night classes when I have you guys, eh?

Now that I've created something that works, I can start on the real thing.

imax
04-11-2008, 08:39 PM
congrats, and good work!

Infoamtek
04-12-2008, 07:55 AM
By George, I think he's got it.

Scottzilla
04-12-2008, 05:34 PM
It's alive!

Smiley
04-17-2008, 02:47 AM
O' Christmas tree, O' Christmas tree....

http://img88.imageshack.us/img88/5031/loc010jv4.jpg

Almost done with my prop.

Scottzilla
04-25-2008, 01:24 PM
Nice work. I can't wait to see your prop.

icandrawem2
05-01-2008, 12:23 AM
Thats awesome man it looks just like a real workbench with real tools! sweet prop!

Smiley
05-14-2008, 04:06 AM
There, it's done!

http://img216.imageshack.us/img216/2954/loc148sp7.jpg



Project video and pictures: http://s9.photobucket.com/albums/a89/dhyde/LOC%20Project/

and here's something else I made: http://s9.photobucket.com/albums/a89/dhyde/FUP%20Project/ (inspired by Gore-Galore's torture boxes)