Electronics 101...?

PHArchivist

Need help with some wiring.

Planning on connecting 6 1.5v LEDs together. That's it. Nothing fancy like flashers or mixed bulb types (like mini-mag bulbs mixed wiuth LEDs). Using white LEDs which are costly; don't want to screw it up.

So...

--1.5v X 6 = 9 so do I just use a 9v battery?
--Do I need anything tricky like resisters or capacitors?
--Do I just connect all the positive leads and all the negative leads and run them to the battery?

Bear with me as I know little or nothing about wiring...

Gigatron

You may need 1 or more resistors depending on the Ohm ratings of the LEDs

http://ourworld.compuserve.com/homep...Bowden/led.htm

Other than that, a 9v should work fine and yes, you can connect all the positive leads together and all the negative leads together and connect them to the corresponding battery leads.

-Fred

sycor

I don't think you will need a resistor. But there was a nice little program that I found once that I can email you that might help. Shoot me a PM with your email. it's just a simple .exe file so you don't actually have to install it. it will tell you what you need. Just have to plug in the information.

quarryman

I'm no electrical engineer, but I think that if you run them in series ( meaning the + of one into the - of the next one, daisy chaining them together) you're probably ok without a resistor. But if you connect all the +'s and -'s together that's running them in parrallel, and without resistors on each one, I think you'll smoke them all.

ursus43

http://www.theledlight.com/ledcircuits.html
http://led.linear1.org/led.wiz
http://www.luxeonstar.com/resistor-calculator.php

masterjedi322

You should always use a resistor as that is what will limit the current draw of the LEDs. Without a resistor, the LEDs will draw current until they fail...which is bad, Mmmkay.

Sean

PHArchivist

Here's the specs on the LEDs

exoray

What model or part number are your LEDs as that sheet for the most part is useless...

White LEDs are almost never on the low end around 1.5 volts, most start at about 3.5 volts and go up...

Did you get the CMD333UWC-ND white LEDs? If not disregard the below for now as it's based on those LEDs... If you got a different part number toss it up so I can get the right specs for it...

If so they are rated 3.75 volts @ 20 mA

So that means you can do two things, cut one leg short on each LED and attach a single 270 ohm resistor to each led, then wire each LED directly to positive and negative on the battery like this...



Or you can do it like this which is the preferred method as it' more efficient...



Note when you do the LEDs in a pair you use a lower value resistor, and as a rule of thumb if you can't get that value resistor go then next value higher...

Also on future purchases a word of advice since you commented on price, please shop around for your LEDs prices swing from pennies to dollars... Granted I order in bulk but I pay about 4 cents a piece for white LEDs delivered, they are not that expensive anymore, and yes I know many retailers still charge multiple dollars for them...

ShackMan

4 cents is a great price ... my last bulk purchase ('bout 3 years ago mind you) was about 20 cents each.

As Exo said, use the series-parallel combo and you'll be fine.


ATM
ShackMan