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]

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.