Proper Wiring for 2 LED's?

Proper Wiring for 2 LED\'s?

I am new to electronics and LED's. I am going to make a LED flashlight. I have 6 volts, 2 3.6 volt LED's, and 2 150 ohm resistors.

Is this the proper way to wire it: Go to www.tnni.net/~slruss/schematic2.jpg to see the schematic I drew.

Thanks,
Sperry

Re: Proper Wiring for 2 LED\'s?

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by slruss:
I am new to electronics and LED's. I am going to make a LED flashlight. I have 6 volts, 2 3.6 volt LED's, and 2 150 ohm resistors.

Is this the proper way to wire it: Go to www.tnni.net/~slruss/schematic2.jpg to see the schematic I drew.

Thanks,
Sperry<HR></BLOCKQUOTE>

Yes, you will have no problem with that. Although a lower resistor value would make it a little brighter. But what you have will run real cool.

Re: Proper Wiring for 2 LED\'s?

I recently answered a similar question for someone else. Go here, and see my post down at the bottom. If you want maximum brightness, this is the way to do it.

Also, for your schematic, you only need one resistor in series with the 2 LEDs hooked up in parallel, but what you have will work fine as well.

Re: Proper Wiring for 2 LED\'s?

Thank you for your replies. I will try that with the potentiometer too. I still don't totally understand the differences between putting them in series or parallel. One place said that if you wired 2 resistors (150 ohm) in parallel you would get 75 ohms. But I guess that is without the LED's connected to them? Or 2 LED's in series with one 150 ohm resistor?

Thanks Again,
Sperry

Re: Proper Wiring for 2 LED\'s?

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by slruss:
Thank you for your replies. I will try that with the potentiometer too. I still don't totally understand the differences between putting them in series or parallel. One place said that if you wired 2 resistors (150 ohm) in parallel you would get 75 ohms. But I guess that is without the LED's connected to them? Or 2 LED's in series with one 150 ohm resistor?

Thanks Again,
Sperry<HR></BLOCKQUOTE>


Series essentially means the electricity flows through only one path, whereas parallel means it splits into 2 or more paths. Your circuit has two subcircuits connected in parallel, that each have a resistor and an LED together in series.

What I'm saying is that you only need one resistor connected to the battery, instead of the 2 that you have in the circuit. Keep the LEDs in parallel the way you have them, though.

Yes, that source is right about the resistances when hooked up in parallel. With the LEDs in there, the overall resistance of the circuit is simply a bit higher.

Re: Proper Wiring for 2 LED\'s?

Okay! Thanks a lot for your help. Now all I have to do is put it together and see how it works.

Sperry

Re: Proper Wiring for 2 LED\'s?

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Lux Luthor:

Also, for your schematic, you only need one resistor in series with the 2 LEDs hooked up in parallel, but what you have will work fine as well.<HR></BLOCKQUOTE>

IMHO slruss is better off with the 2 resistor version shown in the schematic, where each LED has its own current limiting resistor. The reason is that the two LEDs might have slightly different forward voltage drops, due to temperature or production variations. When you connect LEDs in parallel without separate resistors, then the LED with the lower Vf will take more of the current.

In the extreme case, you can get a situation where one LED draws more current, gets warmer, and as a result has its Vf drop, drawing still more current.

If both LEDs are close to equal in Vf, then putting them directly in parallel with a single current limiting resistor will work; but resistors are cheap compared to the LEDs

-Jon