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LED Throwie Safety

R3BORN UK

Jan 15, 2013
8
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Jan 15, 2013
Messages
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This is going to be UNBELIEVABLY basic, but I volunteer at a junior school so I need to check and double check EVERYTHING :D

Want to make some throwies with the kids for a lunchtime project. I've found a bulk lot of 100 cheap leds, that come in red, green, blue, yellow, and white:

http://www.ebay.co.uk/itm/230827935983?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

Now I understand the safe voltages/amps across each colour of LED are different, with red and yellow typically sitting way below the outputted 3v from your generic cr2032. But I also know that throwies general operate fine without a resistor, and without the lithium battery exploding.

Question is this, should I pre solder the LED's with resistors, JUST to be safe?

http://www.ebay.co.uk/itm/Carbon-Re...al_Components_Supplies_ET&hash=item1e623ec1c3

Thank you for your time.
 

CocaCola

Apr 7, 2012
3,635
Joined
Apr 7, 2012
Messages
3,635
Since they are short lived disposible toys, don't worry about the resistor... The coin cell will die long before those 'super' bright LEDs puke out due to slight over current they might get... Also the coin cell itself will puke and self limit current due to it's own internal resistance before it can provide any significant amount of current that would immediately damage the LED significantly or even noticeable...

The short of it don't worry about resistors in this experiment, you will be fine just sliding the LEDs over the 2032 batteries...

BTW if I can't readily locate my LED tester that has limited currents, I will use a 2032 for a quick LED test without hesitation, even on standard LEDs...
 

R3BORN UK

Jan 15, 2013
8
Joined
Jan 15, 2013
Messages
8
Since they are short lived disposible toys, don't worry about the resistor... The coin cell will die long before those 'super' bright LEDs puke out due to slight over current they might get... Also the coin cell itself will puke and self limit current due to it's own internal resistance before it can provide any significant amount of current that would immediately damage the LED significantly or even noticeable...

The short of it don't worry about resistors in this experiment, you will be fine just sliding the LEDs over the 2032 batteries...

BTW if I can't readily locate my LED tester that has limited currents, I will use a 2032 for a quick LED test without hesitation, even on standard LEDs...

I never bother myself at home, but like i said, the kids will be putting these in their bags and taking them home. So i must be 100% sure.

Thanks for the prompt response
 
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