# tea light terrified



## JAGGER777 (Oct 5, 2010)

Hi I am new to the forum, I came across the tea light hack, and I had a couple questions. I sent a pm to otaku but I figure the more knowledge the better right? I know nothing about wiring, but I'm trying to run 5 flicker tea lights ( http://www.lamplust.com/battery-oper...er-p-1104.html ) with timers and want them to run to a 12V DC Adapter ( http://www.modeltrainsoftware.com/12vdcadapter.html ) so I can plug in the candelabra. the led calc gave me this. +----|>|----|>|----|>|----|>|---/\/\/----+ R = 1 ohms
+----|>|------------------------/\/\/----+ R = 470 ohms
My question is so if I read this right I can use 1 wire that goes from negative to resistor to 4 of the leds and then to positive, and then 1 wire from negative to resister to led to positive. So I would need only 2 wires? I would have thought the resistor went on the positive end before the leds but the diagram leads me to believe otherwise. also do the length of the wire runs make any difference? it's a 2 ft geometric squares wall candle holder with plenty of space between holders. thought I'd run the wires along the metal squares to the different holders so you can't see them. oh also what kind of wire do I need? thanks for any help you guys might give me. in retrospect i was thinking I could have used non timered tea lights andjust put a light timer on the plug outlet but ahh well.


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## corey872 (Jan 10, 2010)

Well, 'technically' you are correct in the set-up. Though I think you are going to run into a couple of issues because the LED's are 'flicker'.

I'm thinking when you put several flicker LED's in series - when one LED starts to flicker, it will automatically be cutting current to the others in the string. With 4 in a string, you'll probably just get a dim glow - if anything at all. Secondly, we've had some posts of flashing LED's which refuse to work if the '-' side of the LED isn't tied directly to ground. So, going "+..LED...resistor...-" would cause the flashing LED not to work, and might cause issues with a flickering LED, too (I think it tweaks the little micro-circuit inside the LED). I have not specifically heard of issues with flicker leds, but I'd think the best way would be to put the resistor on the + side and leave the - side always tied directly to ground. In summary...flickering / flashing LEDs in series...probably won't work....resistor on ground may also be bad.

So what to do? Well, the most trouble free set-up would be to run the 5 LED's in parallel. Just make up 5 strings of:

"+.....470 OHM.....LED....-"

There should not be any issues with wiring length, unless it's super small wire, or very long runs, but several feet of even 22AWG should be fine. As a double check, the 470 ohm resistor looks like it should be a good match for 12V supply and 3V LED. If you happened to have a 5V supply, that would be a little more closely matched to the LED and a little less power burned in the resistor - but we're talking a few tenths of a watt either way, so not a huge difference.

HTH


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## HomeyDaClown (Oct 3, 2009)

What he said.

Use one 470 ohm resistor on each tea light's positive terminal, tie all the negative (ground) terminals together. Then tie all the remaining resistor leads together to connect to your 12 volt positive.

Multiple flicker or flashing leds can act unpredictably when connected in series.
Parallel is the way to go.


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## scream1973 (Dec 23, 2007)

could you not put the resistor onto the main lead and then tie all of your wires off that main so the main would only be supplying 3.x volts vs using multiple resistors?

so like ----resistor ----< multiple leads


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## corey872 (Jan 10, 2010)

Again, 'technically' yes you could run one resistor - and if it was most any other circuit that would be the way to go. However, with LED's, they have an inverse temperature to resistance relation. Basically, the hotter they get, the less resistance they have.

You could probably get away with one resistor and a bunch of well matched LEDs - in fact I have done it to get by. But, if one LED draws a bit more power, it gets hotter, resistance drops, and it starts to draw more power...more heat....rinse, repeat, and suddenly that LED blows. The power is dumped on the remaining LEDs and they blow with ever increasing speed.

Flickering or flashing LEDs would be worse. You might have 4 LED's dim and one bright - or worst case, 4 LEDs off and one on. So the 'ON' LED really gets dumped with power and probably burns up. 

For a 100% reliable and long lived system, I'd run the :
'+......RESISTOR.....LED.....-'

Properly assembled, it should work 100% reliably and last virtually forever.

(In the OP's case, you could run one + and one - wire up the base of the candelabra, then split off at a convenient location...no need to run 5 power and 5 ground wires directly from the supply, but each LED really needs it's own resistor)


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## HomeyDaClown (Oct 3, 2009)

scream1973 said:


> could you not put the resistor onto the main lead and then tie all of your wires off that main so the main would only be supplying 3.x volts vs using multiple resistors?
> 
> so like ----resistor ----< multiple leads


Yes, you could do that, but you'd need a 1.5 watt 100 ohm resistor to drop the 9 volts and limit current to 100 milliamps (.02 x 5) without overheating. Still the current draw would fluctuate and quickly turn those tea lights into blown fuzes. We call that a smoke test.

¼ watt resistors are much easier to find and much cheaper ($1 for 5 at Radio Shack) and could fit right inside the tea lights. The bonus here is that you now have individual 12 volt tea lights.

http://www.radioshack.com/product/index.jsp?productId=2062342


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## JAGGER777 (Oct 5, 2010)

*thanks*

Hey thanks all for the help, It's appreciated, now if I can only drill through the glass votive holders without breaking one


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## corey872 (Jan 10, 2010)

That is a pretty tall order! I'd probably try to find something in plastic - as you're using tea lights, it really doesn't need to be heat resistant.

If you have to go at the glass, (assuming you have a glass drilling bit) I'd probably build a dam of clay around where you want the hole drilled. Fill it with some type of lubricating / cooling oil - kerosene or lighter fluid works pretty well.. Glass bits usually do best running very fast speeds with very low feed rates / pressure. Ideally in a drill press, so you have better control. Just when the bit is ready to pierce the glass is the critical time. Too much pressure and it will shatter for sure. So go at it slow and really go slow when piercing.

Depending on how your votives are shattering, they may be tempered (unlikely, but possible) - this would tend to give thousands of small chunks not long after the bit touches the glass. Tempered glass simply can't be drilled. If they are breaking into shards soon after the bit touches the glass, they may still have some residual stresses and be hard to drill. If they are breaking as you push the bit through to enlarge the hole, you may just need to go slower and with less pressure.


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## HomeyDaClown (Oct 3, 2009)

I've used my Dremel with a grinding cone to drill through glass. It turns the glass into a powder (wear a mask) and leaves no sharp edges behind.


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## JAGGER777 (Oct 5, 2010)

*tea light terror part duex*

hey another quick question for ya, by the way got the votives done and wired, glass drilled, it was tense but anyway, I was originally going to order out a power supply and female adapter but found a 12v I had sitting around and pulled a female plug out of an old dazzle I had. Does the female part have to be rated the way a power supply does? They fit and I did take a chance and hook them up they do work, also the adapter I was looking at was 12v mA 1000 specifically sold for leds, this ones 12v 600mA will differing mA's matter in my tea light senario? thanks for the diagram by the way it helped
any power supply to avoid using, like don't use a switching power supply or something like that, mind you I have no idea what I'm talking about so bear with me and give me as much info as possible.


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## corey872 (Jan 10, 2010)

Good deal with the votives - glad you were able to pull it off. The power supply shouldn't matter much. You've got 5 LEDs x ~20 mA each, so ~100mA total. Either power supply is well beyond that. The ratings of the plugs also shouldn't matter too much at these low power levels. 

If you decided to step up to bigger/brighter LED's like I show in my tea light hack, those run about 150mA each, + the 20mA driving LED, so ~170mA total x 5 = 850mA. You could probably still squeeze that onto the 600mA supply as the flicker LEDs don't draw full current for very long - and the time all 5 would be full on is even less. Of course safest/most reliable would be to go with the 1000mA supply to allow some overhead. 

But again, with the normal tea lights, the small supply and most any connector will be good for 100mA and a couple watts.

?? Are we going to get a pic of this thing when it's all done? Sounds pretty cool!


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## JAGGER777 (Oct 5, 2010)

*pics*

yeah I took a picture last night but I gotta figure out how to host it now.


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## Otaku (Dec 3, 2004)

You can upload it to an album here, then link the image in a post. You may have to have a minimum number of posts to be able to create and album, though.


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## JAGGER777 (Oct 5, 2010)

*The battle continues*

while I work on these pictures I'll gripe about wiring I had such a tiny space behind this thing to hide the wires. I started with 3m double sided molding tape. had tendency to fall off. then moved on to hot glue, messy has hell, plus when I get super close it looks crappy at the edges. hard to see unless your up close but to a perfectionist, it drives me bonkers. The multiple connections under the tea lights are a mess too, hard to make a clean look there. Covered with black tape to hide it at the moment. Have now moved onto super glue seems to have solved the problem but still a prob under tea lights. In all honesty all this is almost unnoticeable unless you look for it, but when it's your creation nothing is ever right in your eyes. hope to get somes pics up soon


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## JAGGER777 (Oct 5, 2010)

*allright lets try flickr pictures*

IMG_0230 | Flickr - Photo [email protected]@[email protected]@http://farm5.static.flickr.com/4129/[email protected]@[email protected]@[email protected]@[email protected]@9980ae0629


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## JAGGER777 (Oct 5, 2010)

*hmmm*

well link works but no dice on just showing it in forum, gonna try once more


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## JAGGER777 (Oct 5, 2010)

*try 2*


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## JAGGER777 (Oct 5, 2010)




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## JAGGER777 (Oct 5, 2010)

*screw it just click the link*

screw it just click the link


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## JAGGER777 (Oct 5, 2010)

*tea light terrified done pics sorry for the wait.*

hey this is for everyone who helped me, thanks again. also, planning some fancy solar powered outside lights for my mom for christmas. if everything works out I'll post something.

IMG_0009 | Flickr - Photo [email protected]@[email protected]@http://farm6.static.flickr.com/5250/[email protected]@[email protected]@[email protected]@[email protected]@7f2e7894e3


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