# What Makes a Tea Light Flicker?



## ScreamReaper (Feb 21, 2010)

I'm building a prop right now that needs a flickering LED. I took apart a flickering tea light to disassemble it from the circuit board, and reassembled it in series. The problem is, it doesn't flicker any more. I then looked closer at the circuit board and there was a component I could not access due to a little black blob over it. My new series circuit containes the batteries, the switch, diode, resistor and LED. I'm missing the part that actually makes if flicker though. Is it an IC? Is it a transistor? 

I guess my question is, what component am I missing, and how can I gain access to it on the circuit board? If accessing it is out of the question, what component can I use to replace it?

THANKS!!!


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## HomeyDaClown (Oct 3, 2009)

Rocky Mountain Terror said:


> I'm building a prop right now that needs a flickering LED. I took apart a flickering tea light to disassemble it from the circuit board, and reassembled it in series. The problem is, it doesn't flicker any more. I then looked closer at the circuit board and there was a component I could not access due to a little black blob over it. My new series circuit containes the batteries, the switch, diode, resistor and LED. I'm missing the part that actually makes if flicker though. Is it an IC? Is it a transistor?
> 
> I guess my question is, what component am I missing, and how can I gain access to it on the circuit board? If accessing it is out of the question, what component can I use to replace it?
> 
> THANKS!!!


That black blob protects the flicker integrated circuit which is buried underneath. You can however buy LEDs that have the IC built in like these:
http://www.goldmine-elec-products.com/prodinfo.asp?number=G17848


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## Otaku (Dec 3, 2004)

I assume that you needed to remove the LED from the tea light case due to space limitations or wanting to use a different power source. You can just solder wires to the thru-holes on the circuit board and run those to where you need to have the LED.


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## Graverobber (Dec 7, 2010)

Based on HomeDaClown's link to the flickering LEDs, I would bet that flickering mechanism is integrated directly into the LED. That black blob is protecting / concealing some other circuit but it might just be a current regulator or resistor.


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## Otaku (Dec 3, 2004)

All the tea lights I've cannibalized have the flicker circuit under that blob - I haven't used any with the Type 2 LEDs yet. The LEDs don't flicker when removed from the board.


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## corey872 (Jan 10, 2010)

Yep - sounds like you've run into the 'Type 1' tea light. In that case, it's more the circuit you're after, not the LED. Though I don't think there is any good way to extract the circuit from the board. If you can deal with the entire circuit in your design, one option is to leave it all together - or possibly run some wires from the board to the LED. 

Generally, I've found the cheaper dollar store tea lights have the flicker LED which is actually easier to deal with. The more expensive (Target, Hallmark, etc) tend to have a complete circuit. I'll PM with a bit more info.


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## ScreamReaper (Feb 21, 2010)

*Great Idea!*



Otaku said:


> I assume that you needed to remove the LED from the tea light case due to space limitations or wanting to use a different power source. You can just solder wires to the thru-holes on the circuit board and run those to where you need to have the LED.


Why didn't I think of that!!! Great idea.


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## hpropman (Jul 27, 2008)

Rocky Mountain Terror said:


> Why didn't I think of that!!! Great idea.


Keep in mind that the circuit is only expecting to see one led if you add more in series they may not light due to the voltage drop of the additional leds. If that is the case just add a transistor between the circuit and the leds and you should be fine.


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## ScreamReaper (Feb 21, 2010)

I should only need the one. This should be a cool little prop once I get done with it. I don't want to blow the surprise, but I'll be sure to post pics and videos when I get done with it.

Thanks for all of the help! It's truly appreciated.


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## JustJimAZ (Aug 19, 2010)

Any update?


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