504Views6Replies

Author Options:

LED circuit? Answered

I recently purchased a few LEDs for a project, 2 blues and four reds. I need a way to power them all for months at a time. Would a nice soul be kind enough to draw up a schematic for me, considering I know NOTHING about this stuff? Here are the schematics, taken right off the back of the packets. 4 Red LEDs: Forward Current: 28mA max Forward Voltage 2.6 V max 2 Blue LEDs Forward (supply) Voltage: 3.7 typical, 4.5 Max Forward (supply) current: 20mA typical, 30mA max Any help?

6 Replies

user
death defyer (author)2009-06-25

there u go make sure the power supply is from a wall adapter of 12 volts or else a battery couldnt power it and if 100 ohm resistors dont work try 10k ohm

Select as Best AnswerUndo Best Answer

user
Rotten194 (author)death defyer2009-06-27

Thanks for the info, however that file is a .tmp file and I am unable to open it. Would it be possible to convert that to an image? Thank you.

Select as Best AnswerUndo Best Answer

user
Bot1398 (author)Rotten1942012-01-15
user
death defyer (author)Rotten1942009-06-30

i am sorry i cant and its a .sch schematic

Select as Best AnswerUndo Best Answer

user
kadris3 (author)2010-09-20

red leds typically have 2.1 vdc at 20 ma. this is what you use if you want them to last. the screaming led specs you give a max(never exceed under any circumstances). they may last for a while using these figures. a 12vdc supply, that's exactly 12v will light 5 red led's in series with a 180 ohm resistor. if it is regulated 12v and never exceeds 12v then 100 ohms can be used.
for the white leds use 3.4 vdc and 20ma. 3 white leds in series with 180 ohms
works well. by the same token, a regulated supply can use 100 ohms for current limiting.
good luck with your project. unclecytheledguy.

Select as Best AnswerUndo Best Answer

user
rickharris (author)2009-06-26

http://led.linear1.org/category/led-basics/ will help you a lot have a look round the site and read up on LEDs

Select as Best AnswerUndo Best Answer