[Vlad]

I'm looking to make a "buy" on a fairly large qty. of LED's and battery clips. Can anyone tell me where and from whom they get theirs now? I know that some have recommended cwithk on ebay, and I have also seen besthongkong having some similar if not better deals. Anyone ever dealt with either of these two? also, I want to buy a batch of 9 volt battery clips, but the best price I can seem to come up with is 4 for a $1. Is that about right?

 

[Zombie-F]

I get all of mine on ebay directly from Hong Kong. You can get like 50 LEDs for about $5 - $10 depending on color.

You want 5mm LEDs by the way.

Here's their store's url:
http://stores.ebay.com/BestHongKong

 

[Rhiannon]

Zombie- F...total newby question...I'm going to start this year with the LEDs and still need to study up more, but I want to order soon...the Hong Kong site is great, but confusing...could you give me the stats on what would be a general size? got the 5mm part...would be using them for eye props, eyes in bushes etc...thanks,
Lisa

 

[Zombie-F]

5mm is the size of them. Their eBay store is a little confusing, but if you browse through their listings, you can find most 5mm LEDs in all colors and in quantities of 50, 100, 500 and 5000.

The MCD number that they list denotes brightness. The higher this number, the brighter the LED.

Also, look in each listing for the DC Forward Voltage (which is usually 3.4 V for their LEDs) and the current for all the LEDs I've ordered from them is 30 mA.

With those numbers in hand pick what size battery you're going to use (I usually use 9v because of their small size). Then, you can calculate what size resistor and how the circuit will be wired with a useful resource found here.

Just type the numbers into the fields in the form, check off "wiring diagram" and click "design my array". It will spit out what size resistor to use and how-to hook it all up.

 

[Vlad]

Any sources on the battery clips and pricing?

 

[Zombie-F]

I always just get my clips from Radio Shack. I should source out a better place than that though. There has to be someplace that sells them cheaper than they do.

 

[Vlad]

Like I said, the best online price I've found is 4 for a $1. What are you paying at RS ?

 

[Zombie-F]

5 for $2. I'm shocked there's none listed on eBay for less or even bulk amounts.

I wonder what Digi Key wants for 'em...

 

[sgtdrpepper]

You might try here also
http://www.mouser.com/?handler=data.listcategory&Ne=601&N=1201
For the battery clips.

 

[Vlad]

Zombie. what MCD Leds do you use? I just ordered some 6000 mcd blues.

 

[Zombie-F]

That's what I just got. I just ordered some blues a week ago. I haven't made the blues yet though. So far, I've done Orange, Red, Green and UV.

Speaking of which, my order should be here tomorrow or Thursday.

 

[Vlad]

The reason I have to get going with this, is to reduce the electrical load that I'll need throughout the haunt. I turn on my haunt, and the whole block dims for a few seconds, lol. I need to go with LED lighting wherever possible from now on.

 

[Zombie-F]

I know what you mean Vlad. Last year, with the three foggers going, I had to unplug the two orange floodlights I point up at my house because they kept throwing the breaker. That's why I'm switching a bunch of floods to LEDs.

Plus, for some of the props (like the birdbath) I don't need 100 watts of light for it be illuminated well. The LED spotlight is quite enough for it.

I better get started soon. Time's ticking away on me.

 

[sgtdrpepper]

Zombie
I just received an order of UV LEDS and would like to know how many LEDs you are using in your spots? I connected 2 together and they seem to look ok but are not very bright(which is what I wanted) but I do need them to be a little brighter.
Thanks
SGT

 

[Zombie-F]

I use three LEDs in most of my spotlights. But, if you want super-duper-bright, you could move up to 3/4" PVC pipe and use 4 - 6 LEDs in a single spot. You'll have to come up with more creative ways of wiring them up though as wiring them all in series will produce a very dim light.

 

[SpectreTTM]

Hi Zombie -F

Not to be a wise guy but shouldn't you be connecting multiple LEDs in parallel?

When you connect them in series you are causing a voltage drop of about 1.2 V (higher depending on the LED) across each LED as well as the resistor.

So lets say

9v Battery
1 LED
1 330 ohms Resistor

(9-1.2)/330ohms = 23 MA Good

now Lets add 2 more LEDS

9v Battery
3LED
1 330 ohms Resistor

(9-1.2-1.2-1.2)/330ohms = 16 MA Dim

Hope this helps.

 

[Zombie-F]

That's what I'm saying. When I do three LEDs, I do two in series and a third LED in parallel to that. I use this tool to calculate the best ways to do it:

http://led.linear1.org/led.wiz

Of course, for my Spotlights, I'll be using a 12v source, so three LEDs in series will be fine with a 68 ohm resistor.

 

[Zombie-F]

Also, I'm curious as to why in your example you used the same resistor for the 1 LED circuit and the 3 LED circuit.

 

[SpectreTTM]

Hi Zombie -F

It was just a quick example. And a guess at your set up.

What is the forward Voltage drop of the LED?
I believe they reccomend 20 MA.

Your hook up should look like this.

That way the all the current is equal across all 3 leg (LED resistors).

Sorry about the confusion.

 

[SpectreTTM]

Hey Zombie-F

I just figure out why the difference between the 2 circuits.

My way draws 20 ma / leg for a total of 60 ma drawn from the supply.
Also needs more hardware.

I guess the big thing is not to have bigger drops than the suppy can take.

And depending on the type of LED that drop can be a good amount.

Thanks for your understanding.