LED assistance desired, Just a little project Options

[Bigmeanbulldog55]

I'm doing a little project for my Animal Training class and I'm having some problems with my LED set up. I've got some regular Radio Shack brand LEDs, model 276-1622. The power source is 4 AAA batteries putting out about 6.4 volts (volt meter measured). I'm only lighting one LED at a time with the 6.4 volts. I've done this twice now. The light flashes and then won't light again. Am I really blowing these things with little little voltage? I don't understand because I had some hooked up in my car running the 13-14 volts between the 2, and they worked just fine. They were a different brand though. What do I need to make this work?

[vsideboy]

I would say that yes you are blowing them mate.

Usually LED's are only 3volt max so banging 6v will blow it.

You would need a resistor before the LED to drop the voltage beforehand.

This is a site that I used when I was playing with LED's.

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

you put the source voltage, the LED details and number of LED's to use and it shows you what resistor you will need.

You should be able to get the LED details from the place you bought them, otherwise check on ebay or something as theres always tons on there with the respective details.
The mcd value relates to the max brightness, e.g. red usually max at 7,000 - 10,000 whereas white or blue can go to 22,000.

hope it helps mate. lucky they arent too expensive eh, when you blow them all when learning haha. I have done the same though mate, had one shatter into pieces when I accidentally wired it direct to car battery!

[Bigmeanbulldog55]

I've ditched the 4 AAA, and opted for a set up with one AA battery per LED. Do you think that will work? I'm going to try it on an LED I don't need first. This isn't the ideal set up for me, but it works for now. If 3v is max, I should be able to get away with 2 AA or 2 AAA batteries per LED. I want them as bright as I can get them. I guess I'm newer to LEDs than I thought I was.

[vsideboy]

Just use the calculator mate.

Each LED takes up a certain amount of power so you could run them off 240v if you linked enough together!!

For example, you can run 1 from a car battery with a large resistor in series with the LED

+13v --R--L-- -13v

or

you can run 4 leds in series with a much smaller resistor from the same battery.

+13v --r--L--L--L--L-- -13v

they should all light up the same in both instances.

You can also buy LED's that are 5v and 12v so you have a TON of choice.

Let me know if you need any more help.

[Bigmeanbulldog55]

It's just that each light needs to light up one at a time, but also have the ability to light up all at once. That's why I'm thinking 3v per light. I just run a simple switch with a power source to each light.

[vsideboy]

yeah should be ok mate.

how many leds you planning on using and are you just going to have a switch for each one?

Dan

[Bigmeanbulldog55]

yeah should be ok mate.

how many leds you planning on using and are you just going to have a switch for each one?

Dan

As of now it's just 4. As part of my animal training training, I've worked with more rodents than anything. I'm trying to build a self contained animal training device. I start with simple behaviors in rodents and hopefully adopt the principle to larger animals. I'm using each LED on its own individual switch as cue lights to tell the rodents were to be or what to do in the presents of a certain color/position of a light. It’s not really as easy as it sounds, but it’s a work in progress.

[playr158]

wat you need to do
is

use a 9V battery

attach a 220ohm resistor to the positive side of your LEDs and you will be fine!