Before I fry all my LED (buckpuck & battery question)

[Kitsune_sempai]

Hi guys,
I've been super interested in lightsabers made with LED string and after reading and reading and reading, I've decided to order some parts to make my own for a cosplay coming up. I ordered myself this battery ( http://www.thecustomsabershop.com/74...Pack-P758.aspx ) and I'll connect about 60 led (3.4 V & 20mA each) in two group of 30 in parallel in series. I made my calculations and if I'm not wrong it would require 6.8 V and 600 mA to run the string correctly (right?).

At first I though of using resistors but a Buckpuck really seems like the way to go ( this one http://www.thecustomsabershop.com/Bu...6-wire-P9.aspx ) since I heard it can regulate the voltage on it's own (...right?) and also help reducing the heat of the overall setup.

My Leds haven't arrived yet and even though I have some to spare I would just like to know if my overall setup makes sense and is safe, also since I'll be making the handle mostly out of PVC pipes, are the batteries very hot? I know some PVC can resist high temperature but I dont want my sword to be too hot to the touch (I could also have an external battery pack if it's safer).

thank you very much for taking some time to read and answer my questions =)

PS: my setup wont incorporate a sound board or anything just the battery, a switch, the led and the buckpuck.

[hedgehog1]

I use the 6 wire dimmable buck pucks; but the risk of counting on dimming to control the current is likely to fail.

May I suggest a slight variation to your plan?

Buck Pucks are available in 350 ma and 500 ma sizes, too. TCSS doesn't stock them as the smallest size a typical saber uses is 700ma. But the they are available from electronic supply houses in the smaller sizes. The 500 ma size will drive all your LEDs at a good brightness. This will also improve your battery life and reduce heat.

PVC sabers have a long and proud tradition, by the way.

[Silver Serpent]

Or you could wire up your LEDs in sets of 35. Then 700mA would be perfectly fine.

[Kitsune_sempai]

then that's what I'll do, can always use more led anyway =)
for the voltage though will the buckpuck regulate it as well (so it doesnt give too much?)

[hedgehog1]

The voltage will auto adjust to keep the current a constant 700ma, so it takes care of itself. So your (newer) plan of 35 x 2 will blind your enemies and impress your friends.

[Kitsune_sempai]

I just received some the custom switch I ordered today and to my surprise they require 12V and 20 ma to light up. therefore I'm a bit confused as to how to wire them exactly, they also have weird symbols on them, and before I test the whole set up out, I'd like it a lot if more experienced people would approve of my (very basic paint) schematics (I changed the amount of LED required because the blade will be much shorter than I imagined).
schematic.jpg

I also included the symbols I found on the switch.

also since the switch is an LED in itself does that mean that now the required Ma will be 520? (I dont think thats right though)

anyway any little help is appreciated. (if the lack of Voltage for the led switch is a problem I can always go for a more standard non-led switch)

[hedgehog1]

Can you post a photo of the switch? Or better yet post a link to it so we can see the data sheet on it?

[Kitsune_sempai]

it didn't come with a data sheet but here's a link for it on the website I bought it from http://www.abra-electronics.com/prod...%28Red%29.html and here's some picture I took with my phone (if the symbols are blurry they are the same symbols I drew on the previous schematics)IMG_20130401_224923.jpgIMG_20130401_224937.jpgIMG_20130401_225007.jpgIMG_20130401_225018.jpg

[hedgehog1]

From regarding about the switch, the two sets of ratings are:

The switch can turn on/off 12v @ 20 amps.

The built in led Can be illuminated with a voltage as low as 3.3 volts. That low voltage tells me that the led is a simple 20ma Max led with no built in resistor. If you wire it with a resistor to limit the switch led to about 5ma, that should be bright enough. The led in the switch is really an accessory led (for our purposes).

[Kitsune_sempai]

I hate to ask but I'm a bit inexperienced with three prong switches and I'm a bit confused as to how to wire it into my set up (and using a resistor individualy on it's led).

thank you, sorry for the enormous ammount of questions