# NEED INFO: Evil Mad Scientist LEDs



## Lord Homicide (May 11, 2012)

Folks,

Besides Pod, has anyone ever used these or bought them at a store? I hate buying things online. The flicker LED has everything built in so all you have to do is hook it up to a power source.

http://evilmadscience.com/productsmenu/partsmenu/189-candled


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## typoagain (Feb 27, 2012)

I know nothing about them. But I need a couple of battery holders anyway so I bought 15 LEDs and a couple of holders. I choose the cheapest shipping (that was <$3)

I spent a total of just under $23. for that price how can you go wrong.

I am looking to build several light that hold several LEDs, say 4-6, and a battery pack. I just need someone to tell me how to do it! I have built one in the past but I used pre-wired LEDS.

I want to use them inside lantern I can put out at several places around the yard and power them with rechargeable AA batteries. I try these and see how they work.

I have never used this seller before, but I have had read other places that they are fair and dependable, so we shall see. I had completely forgotten they existed.

Thanks for posting the question. 

Maybe someone will throw out a little advice on how to wire them.


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## Lord Homicide (May 11, 2012)

typoagain said:


> I know nothing about them. But I need a couple of battery holders anyway so I bought 15 LEDs and a couple of holders. I choose the cheapest shipping (that was <$3)
> 
> I spent a total of just under $23. for that price how can you go wrong.
> 
> ...


Wiring them is easy. Get the correct solder gun if you don't have one. Each single wire in a Cat5 wire will carry the current. I wired 4 LED votives together using the striped wire as the negative and solid color as positive on each votive so I could tell them apart. This makes them leads now. Then twisted and soldered the wires together THEN soldered to the positive and negative terminals on the battery holder with a switch on the positive line. Snapped in two AA batteries and it worked. I melted all the battery holders though because I had the wrong solder gun tip.

So for these LEDs, find out which pole is + and which one is - and solder wires to them then to the battery pack.


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## The Pod (Sep 15, 2009)

Well Lord Homicide, I have never seen these or have been able to find them sold locally (other than the little tea lights) and I spent a couple weeks searching for suppliers of these types of LED's. I found Electronic Goldmine sells one for .99 cents a piece but the quality didn't compare. I also looked at EFX-TEK WickLED setup which was really nice and I had used these in previous years, but just seemed too costly for candles. 

I belong the a local group ("Chicago Haunt Builders") and after I showed my findings to the group on these LEDs and how they compared to others versions, we ended up placing a group buy for 1400 of these LEDs. In less then two weeks our group will be getting together to make a bunch of candles with these LEDs for our haunts so I can let you know how that goes. I and my 8yr old daughter have already made several candles using these LEDs and I even built one to run off 12 volt AC which I connected outside to my malibu lights transformer to weather test the candle. It's now been outside running every night for well over 2 months and still looks as good as new.

typoagain: because of the flicker circuit inside these LEDs you can not wire them together in series. Also, depending upon your power source you're using, you will need a resistor to step the voltage down so you don't destroy the LED. If you need help, you can PM me or I'll try to put together some pics and post them when our group does the candle build.


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## Lord Homicide (May 11, 2012)

The Pod said:


> I and my 8yr old daughter have already made several candles using these LEDs and I even built one to run off 12 volt AC which I connected outside to my malibu lights transformer to weather test the candle. It's now been outside running every night for well over 2 months and still looks as good as new.


Do you have any pics of your malibu lights?



The Pod said:


> typoagain: because of the flicker circuit inside these LEDs you can not wire them together in series. Also, depending upon your power source you're using, you will need a resistor to step the voltage down so you don't destroy the LED. If you need help, you can PM me or I'll try to put together some pics and post them when our group does the candle build.


I hate being wrong. I assume these use 3 volts so would you still need a resistor in the circuit using two AAs or AAAs?


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## The Pod (Sep 15, 2009)

Lord Homicide said:


> Do you have any pics of your malibu lights?


Don't have any pics of the candle connected to my malibu light cable. But I'll look at taking one and posting it for you.



Lord Homicide said:


> I hate being wrong. I assume these use 3 volts so would you still need a resistor in the circuit using two AAs or AAAs?


Actually 2.1 volts is their typical voltage, but powering them from 3 volts shouldn't be an issue and you could just add a small resistor just to be safe:

•Color: Yellow 
•Peak Wavelength: 590 nm 
•Package: Round 10 mm 
•Lens type: Milky-white diffused 
•Viewing angle: 50 degrees 
•Intensity: 700 mCd typ. at 20 mA 
•DC forward current: 30 mA 
•Forward voltage (typical): 2.1 V 
•Lead-free (RoHS compliant) 
•Manufacturer: Betlux Electronics 
•Manufacturer part number: BL-L101UYW-B-S3

As for using resistors, I would have to say its a mixed feeling, I've had people tell me they run LEDs without resistors all the time and I have others tell me to always use a resistor even if its just 1 Ohm. I have always used a resistor with an LED.


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## Lord Homicide (May 11, 2012)

The Pod said:


> As for using resistors, I would have to say its a mixed feeling, I've had people tell me they run LEDs without resistors all the time and I have others tell me to always use a resistor even if its just 1 Ohm. I have always used a resistor with an LED.


Just curious, I guess it would be as simple as soldering the resistor(s) to the positive wire and taping it up for protection? Would a resistor have to go to each LED (I'm kind of asking questions that I assume are correct)? The reason I'm interested in this is my clay pumpkin project for my groom table. I've got about 50 miniature hollowed pumpkins that I need to run this LED to and wire each cluster to a battery and switch.


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## Jaybo (Mar 2, 2009)

Lord Homicide said:


> Just curious, I guess it would be as simple as soldering the resistor(s) to the positive wire and taping it up for protection? Would a resistor have to go to each LED (I'm kind of asking questions that I assume are correct)? The reason I'm interested in this is my clay pumpkin project for my groom table. I've got about 50 miniature hollowed pumpkins that I need to run this LED to and wire each cluster to a battery and switch.


You can use the LED calculator here  to help design your circuit.

If you are placing a single LED into each of your pumpkins, you will have to have a resistor for each LED. You would then need to run a common power line and have each pumpkin branch off the line.


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## The Pod (Sep 15, 2009)

Lord Homicide said:


> Just curious, I guess it would be as simple as soldering the resistor(s) to the positive wire and taping it up for protection? Would a resistor have to go to each LED (I'm kind of asking questions that I assume are correct)? The reason I'm interested in this is my clay pumpkin project for my groom table. I've got about 50 miniature hollowed pumpkins that I need to run this LED to and wire each cluster to a battery and switch.


Technicaly you would need a resistor on each LED, however it would probably work just fine with one resistor wired to several LED positive leads but this would probably be called a bad circuit design by some people. Resistors are cheap (I found mine off ebay 100 for $2.50 with free shipping - and not coming from China so I got received them in 2 days after buying them!), just extra work to solder them on.

How big of a battery are you planning on using and how many LEDs do you expect to connect per battery? You'll want to consider this when you're figuring out how long you need the battery to last. We tested running three of these LEDs on a standard 9 volt battery and they lasted about 8 hrs before they stopped working.


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## The Pod (Sep 15, 2009)

This is the 12 volt AC version of a PVC candle that I can connect to a malibu landscape lights tranformer.









Here is the candle connected outside for 2 months:









After dark pic of the candle:


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## typoagain (Feb 27, 2012)

I was thinking to use 4 or 5 of them in a group wired up parallel. I would get whatever power supply I needed. I would like to have some that run off a battery, 9 volt would be nice as would packs of AAs, but I will just buy whatever I need. 

I would also love to be able to run some of them off of a wall wart. 12 volt would be common, but 5.1v and 7a are very popular sizes for phone charges.

I have a few prewired LEDS set up for 12 volt that I will be playing with in a few days.

I don't really need the batteries to last a long time. I only figure to run them for a single night.


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## The Pod (Sep 15, 2009)

typoagain said:


> I was thinking to use 4 or 5 of them in a group wired up parallel. I would get whatever power supply I needed. I would like to have some that run off a battery, 9 volt would be nice as would packs of AAs, but I will just buy whatever I need.
> 
> I would also love to be able to run some of them off of a wall wart. 12 volt would be common, but 5.1v and 7a are very popular sizes for phone charges.
> 
> ...


typoagain, LEDs are really simple to wire up. On these flicker LEDs, the longer metal lead is the positive. You will solder a resistor to this lead. Connect the other end of the resistor to the battery or power source positive, and the shorter lead of the LED to the negative of the battery or power source. You can use this site (http://ledcalc.com/) to figure out what OHM resistor you'll need depending upon what power voltage you're using. Put in the value of your power source, use 2.1 for the Voltage Drop across the LED, 25 is a safe number for the milliamps and use only 1 for the number of LEDs. (because of the circuit inside the LED for flickering, you can not string multiple LEDs together. You can wire several LEDs to one battery/power source in parallel like you said, each one connected to the positive and negative of the power source. If you were using regular LEDs, then you could use other numbers of LEDs in the calculation and string LEDs in series. The site I listed is nice because it'll also provide a picture image how everything gets wired up.)

If you plan on using batteries, I suggest testing one to see how many hours you can get to make sure it'll run the the ammount of time you're looking to have it run for.


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## fontgeek (Jul 24, 2006)

Colored text is hard to read


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## typoagain (Feb 27, 2012)

fontgeek said:


> Colored text is hard to read


Yes,, it can be. But maybe there is a reason some of us use it.

For example, I am on the forum a lot at work when I have a slow night. I can't type worth a [email protected], (hence the screen name) so I use spellchecker on just about everything. The computer does not have a spellchecker on it that will work with this forum and I can't add one. So I write all my post and then copy and paste. But black letters will not show up on the dark background on this site. So if for some reason I want to use a quote, I generally write on a word processor in a color and then copy it over here. Constantly changing the colors creates a whole handful of problems.

Like many people here, I do not read every single post. I do not expect everyone to read what that I post. If someone wants to skip reading my post because it is in a color,that's OK with me. I really do not feel like my questions are all that important.

If my color post are causing someone discomfort, I am sorry. I would just ask that if the color bothers you, than please feel free to skip them.


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## DarkLore (Jan 25, 2009)

What the Hell did that last person write?


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## gooffy87 (Oct 18, 2011)

what the? lol


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## Lord Homicide (May 11, 2012)

Hey Pod, love the Malibu setup...


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