anybody familiar with soldering LED's?

[chinkgai]

so im trying to solder an led to a power source consisting of four AA batteries (6volts total)

here are the specs to the LED in question

i've tried using a 110ohm fixed resistor and the led burns out after a relatively short period of time (like less than a day of usage)

should i use a 150ohm one? higher ohms? lower ohms? thanks EE guys

 

[TechnoKid]

seems to me that max voltage is 4 at 20mA on those LEDs

 

[ThisIsMatt]

n/m

 

[Colt45]

according to the 3.5v 30ma thing, 90 or more ohms should keep it within ratings.

higher resistance = less power = less brightness = longer life.

but 90 ohms is enough to keep it under ratings, so i dont know why it is dieing (sp?) with 110.

 

[TechnoKid]

make sure you are using a heatsink (pliers work well) on the leads to the LEDs when you are soldering to prevent heat from killing the LEDs.

 

[Demon-Xanth]

Make sure you have the right resistor, if it's banded it should be brown brown brown, if it's numbered it should be 111 or 1100. If it's brown brown black, 110, or 11R0 then it's an 11 ohm resistor.

 

[chinkgai]

hey thanks for all the help guys

demon i got the right resistor, i checked with a multimeter

how would i solder two leds to this same power supply? jes solder the two connections on the resistors? one resistor or two?

 

[DanTMWTMP]

Originally posted by: chinkgai
hey thanks for all the help guys

demon i got the right resistor, i checked with a multimeter

how would i solder two leds to this same power supply? jes solder the two connections on the resistors? one resistor or two?

just put them in parallel.

 

[chinkgai]

Originally posted by: DanTMWTMP

Originally posted by: chinkgai
hey thanks for all the help guys

demon i got the right resistor, i checked with a multimeter

how would i solder two leds to this same power supply? jes solder the two connections on the resistors? one resistor or two?

just put them in parallel.

whats that mean? lol sorry im new to electrical stuff

 

[Amorphus]

Originally posted by: DanTMWTMP

Originally posted by: chinkgai
hey thanks for all the help guys

demon i got the right resistor, i checked with a multimeter

how would i solder two leds to this same power supply? jes solder the two connections on the resistors? one resistor or two?

just put them in parallel.

I've always been told serial, and the LEDs don't have too much internal resistance anyways.

Then again, that may just be for the convenience of stringing them out.

 

[NutBucket]

In general you use a 330 ohm resistor for an LED when the source is 5 volts. Wire it in series.

Seeing as how your source is 6, this should be an acceptable circuit.

 

[Demon-Xanth]

DO NOT put the resistor in parallel. If you do, the LED WILL fry, and the resistor doesn't do anything useful. Put the resistor in series with the LED.

 

[Mo0o]

Go to google and look up LED calculator, you can enter in the specs of what you are trying to do and they will tell you what resistors you need.