LED Help Needed

[White-Light]

Hi,

I've been trying to light up my costume for halloween using red glowsticks but it seems I'm simply can't get enought light out of them so I need another light source.

I've been thinking of using some of these:

High Efficiency Red Toshiba description:TLSH180P Forward voltage max. at IF=20mA:2.5V Forward current max.:50mA Reverse voltage max.:4V Wavelength @ peak:623nm Power dissipation PT:125mW Light output min.@ 20mA:2720mcd Light output typ.@ 20mA:10000mcd
As I reckon 10,000 mcd should be quite bright.

I basically want to cast a red shadow on the ground underneath my costume and also red light inside the sleeves.

However, I have very little experience of LED's.

How exactly can I connect these?

Can I connect them using wire in a simple circuit and solder the leads to the wire, shrink wrap the ends then sew them into the costume or will they break off?

Will I have static problems - the garment is 100% polyester?

How can I power them? - will a straight battery pack with 2 x 1.2 volt AA batteries be enough and be stable? I see the 10,000 mcd is claimed at 2.4 volts.

How long will the batteries last? If eg. I use 10 @ 50ma = 500ma total and I have a 1,500mah battery, does this mean they will light for 3 hours?

[T0mmm]

hiya matey, if you go down to your local 'buyology' / hypervalue / cheap junk crap shops,
you might be able to pick up some LED lighting that chavs use under their cars to make them instantly 30000X faster? my local one has these for cheap anyway. you can even get them on a flexible strip (useful for your costume perhaps?)

failing that, if theres enough room you could just shine a nice bright torch into a diffuse red ball/ dome of some kind and get the light from there? LED's tend to have a 'cone' of brightest light don't they


EDIT: ive been trying to search for the cup-like things which you sometimes put washing detergent in and place in with your clothes in the washing machine, but couldnt find a picture haha... what are they called? or an aerosol cap might also work.

[mliptack]

Have you looked at EL wire?

Here is one shop that sells it, just google "EL Wire" or "Electroluminescent wire"
http://www.elbestbuy.com/plugnplay1.html

Its by no means "cheap" but it also isn't too bad. It looks great, pretty darn bright, and many kits are made to run off of a few AA batteries.

[Xytrell]

I basically want to cast a red shadow on the ground underneath my costume

A shadow that's any color but black? Now that's a feat.

I jest, I know what you mean. should be quite impressive if it works.

[Pitts]

Hi

Good luck with your project,,,, I would just like to add whatever you choose to do, if you are carrying any form of betteries under your clothing then fit a fuse right near the battery..

Anyone who has had the experience of say a 9 volt battery in the pocket with the car keys knows this is a reall good way to get burnt (yes it happened to me) they can also explode and maybe even have clothing catch fire !!

So for the want of a few cents fit a fuse right at the battery terminal and make sure you keep the battery terminals covered,,, hate to see you go up in smoke.

Batteries are no harmless little devices like we all think..

Have fun...

Cheers

Ray
NZ

[Psi]

mcd is a pretty useless value for leds. It's not a rating of total light output as most people think. It's infact power emitted by a light source in a particular direction.

So, for example if you have an led with an angle of 10deg, (an led that makes a nice bright spot on the wall at a distance) it will have a very high mcd value.

And if you have a different led, that outputs the same amount of light but covers an angle of 140deg it will have a very low mcd value.

Hence 10000mcd maybe quite a powerful led or quite a dim one depend on what angle the led is

Best way to tell how bright an led will be is to look at how many lumens it is. Failing that look at how much current it can handle, if its a 50mA led and youre running it at 50mA its going to be brighter than a 20mA one at 20mA.

[mixedgas]

Ok, your led has a Vf of 2.4 Volts. You want to run it at 30 mA for its rated value (actually you can overdrive the crap out of most reds, often 70 mA)

PP3 9 volt battery.

calculating the limiting resistor.

so Rlimit = 9V-2.4/.030 = 6.6/.030 = 220 ohms. So a 220 is OK, a 180 is quite bright, and 150 is pushing explosion. You want 1/4 watt resistors so you dont set your pocket on fire.

According to the Energizer battery book, a fresh PP3 is 600 mAh, so at 30 mA you'd have 20 hours for one led, in reality a little less then that.

for two leds in series, which makes less heat in your pocket , R = 120 ohms is the nearest standard size, and you'd actually do a little better on the lifetime.
634 nm leds are plenty bright enough, and are a spooky orange red.

As the previous poster mentioned, 10,000 mc doesn't tell us anything without angle data.

if I could afford a liability lawyer he'd tell me to tell you not to do this,tell me to tell you nothing at all, and then tell me to tell you to use some heat shrink tubing on your leads and solder the connections, so you dont experience 2-3 amps of smoke in your pocket. :-)

But if we all listened to the lawyers about non laser sources and hobby projects life would be pretty boring wouldn't it?
Steve

[tocket]

Easiest way to light a LED is using a CR2032 battery. Just stick the battery between the legs and secure it with duct tape. No resistor needed; the internal resistance of the battery combined with the voltage drop over the LED is enough to keep it healthy. Red LEDs last the shortest, because of the lower drop, but they should still easily last one night.

CR2032s are very cheap if you buy them in quantity. I usually buy a hundred at a time.

[mixedgas]

Easiest way to light a LED is using a CR2032 battery. Just stick the battery between the legs and secure it with duct tape. No resistor needed; the internal resistance of the battery combined with the voltage drop over the LED is enough to keep it healthy. Red LEDs last the shortest, because of the lower drop, but they should still easily last one night.

CR2032s are very cheap if you buy them in quantity. I usually buy a hundred at a time.

Works for me,and it made the guy who patented the Photon Microlight a million bucks.

Steve

[White-Light]

Have you looked at EL wire?

Here is one shop that sells it, just google "EL Wire" or "Electroluminescent wire"
http://www.elbestbuy.com/plugnplay1.html

Its by no means "cheap" but it also isn't too bad. It looks great, pretty darn bright, and many kits are made to run off of a few AA batteries.

I bought some EL wire off ebay but it was really dim despite claims of high brightness.

The best thing appears to be those flexible strips of LED's used for car interiors but given that we have a postal strike over here, getting them before Saturday is impossible.

Given the possible fire risks, I'm beginning to think maybe LED's aren't the answer. I might give up on lighting the floor and just strap some red glow sticks up my sleeves to give an evil red glow down my arms. I think it might be safer and easier. Thanks for all the suggestions though.

BTW, I've also got a canister of canned smoke and I'm going to get some fish air pipe tubing so I can have my suit smoking as well!