LED Trouble!! Help me please!

Hmm...you should only be drawing just over 20mA, a standard 9V shouldn't have a problem with that. I am assuming you have everything wired up in series, like the diagram? Did you try a different battery? If that doesn't help, try upping the resistor size to 330 ohms, and see if that helps.
 
I think that this is its max. not?

3.2V (typical), 3.8V (maximum) So it should be a 270 resister, but as mrgr8ness has said, use a 330 ohms.

Maybe I'm wrong, I don't know :facepalm
 
yeah I have a switch. I just tried 2 9V same problem. Then I tried hooking it up to 4 AA burned the plastic holder. I have it rigged to try 8 AA but I didn't think one LED would take 8 AA to run it. Could I add another resistor on it with the one I have or do I need to completly tak the old resister off and add the new one. Is the switch the problem?


I have a rocker switch do I even need a resistor?
 
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Well I have red to red and black to black and the LED is coming on. Notninja said maybe I am using too much battery. Since it's only 3.5 max volts and I am using a 9V. I am going to try to up the resistor to a 330 and lower the battery to 2 AA or 22 AAA and see if that works. Any other ideas?
 
I've never had any luck using a 9v with leds. either the bat gets hot or burns them. I usually use watch batteries with leds.
D
 
I use 9v for my leds all the time.

It sounds like to have a short. I made a similar mistake the first time I wired mine.

Make sure you have both reds (one from Led and one from Battery) on the 2 switch posts (doesn‘t matter which one goes to which red). The black from the battery goes directly to the black on the led to complete the circuit.

Does that make sense?



BTW… the batteries that got hot or probably now shot (once you fix the short). Get some new ones once you finish the circuit.
 
I think I did this right. Sorry for the bad drawing...

Don't let the + - confuse you on the switch. I should have just put post 1 vs post 2... sorry.

LEDS.jpg
 
Well that explains it!!! I thought on the posts on the switch one was for + and the other was for -. So I guess the switch just needs to break the circuit on the positive side. Ok thank you everybody! Thanks Darth Nickel you think it was a bad diagram but it was perfect! Sometimes I need crayons and paper to get it. :lol:
 
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You are very welcome. I did the same thing when I wired my first LED. After I figured out the problem, I then got a little afraid the battery could have exploded :)

BTW.. other lesson I learned. No matter HOW bad you want to see a LED color DON'T "test" it without a resistor... LEDs don't like too much juice. No light, just electronic fry smell and a little burn on the finger if you catch my drift.
 
Oh, so you had the switch across the battery? Yeah that would explain it, you were shorting the battery out. When the switch was open, your LED probably worked.
 
Well I had to replace the switch and re-wire everything but it works!!!! Thank you everyone! And yes DN I toasted about 4 LEDS before the resistor.
 
Hey TK9950 - I've been burning stuff up so I'm thankful for finding this thread. Do you remember what kind of switch you got from radio shack for this setup?? gracias
 
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