# which is brighter or is there a diff?

#### scytzoh

Joined Nov 8, 2015
14
i looked up the pland for a 14 led array and it gave me 2 possible ways of doing it . im asking just for curiosity sake but i notice the both drew different amounts of power one says draws current of 140 mA from the source the other says draws current of 100mA from the source. is one brighter ? im assumeing if one is it is the one drawing more? would it be noticable if so?? would the one drawing more burn out quicker because its same amount of lights but consuming more??

#### MikeML

Joined Oct 2, 2009
5,444
Without a circuit or data sheet, can't suggest anything...

#### mcgyvr

Joined Oct 15, 2009
5,394
The one with the higher "lumen" rating would be "brighter"

#### WBahn

Joined Mar 31, 2012
29,876
i looked up the pland for a 14 led array and it gave me 2 possible ways of doing it . im asking just for curiosity sake but i notice the both drew different amounts of power one says draws current of 140 mA from the source the other says draws current of 100mA from the source. is one brighter ? im assumeing if one is it is the one drawing more? would it be noticable if so?? would the one drawing more burn out quicker because its same amount of lights but consuming more??
How can we possibly answer a question like this?

You don't give the plans for the two methods, so there is no way for anyone to guess how much of those currents is actually going through the LEDs.

I could make one circuit that had all of the LEDs in parallel with 10 mA going through each for a total of 140 mA and another circuit with the exact same LEDs in series with 100 mA going through each for a total of 140 mA. Which one will put out more light?

Perhaps one circuit has power going to a regulating circuit that doesn't go through any LEDs.

#### GopherT

Joined Nov 23, 2012
8,009
i looked up the pland for a 14 led array and it gave me 2 possible ways of doing it . im asking just for curiosity sake but i notice the both drew different amounts of power one says draws current of 140 mA from the source the other says draws current of 100mA from the source. is one brighter ? im assumeing if one is it is the one drawing more? would it be noticable if so?? would the one drawing more burn out quicker because its same amount of lights but consuming more??
Yes, that is what you should do. You have to consider that more isn't just more. Sometimes it is more but that more includes some of what doesn't help you whereas less is sometimes all of what helps you and nothing of what doesn't. So, I think you know what you need to do.

#### KeepItSimpleStupid

Joined Mar 4, 2014
5,088
Off Topic somewhat FWIW;
A friend owned a consumer electronics store. Someone came in wanted to purchase a stereo amplifier. His only question: "How many watts is this?"

#### WBahn

Joined Mar 31, 2012
29,876
Off Topic somewhat FWIW;
A friend owned a consumer electronics store. Someone came in wanted to purchase a stereo amplifier. His only question: "How many watts is this?"
Did your friend tell him that, for a nominal fee, he could increase the power draw of the amp to whatever wattage he wanted?

#### KeepItSimpleStupid

Joined Mar 4, 2014
5,088
No. But it was just funny. Nothing about RMS, Peak or anything else, just Watts.

#### GopherT

Joined Nov 23, 2012
8,009
No. But it was just funny. Nothing about RMS, Peak or anything else, just Watts.
And if he asked for peak watts? How would the owner have answered him?

#### dl324

Joined Mar 30, 2015
16,722
The lack of relevant information in your post makes providing the answers you seek virtually impossible; hence your post has into something you (hopefully) didn't intend...
i looked up the pland for a 14 led array and it gave me 2 possible ways of doing it . im asking just for curiosity sake but i notice the both drew different amounts of power one says draws current of 140 mA from the source the other says draws current of 100mA from the source. is one brighter ?
Maybe, maybe not.
im assumeing if one is it is the one drawing more?
LEDs operating at the same current could have different brightnesses.
would it be noticable if so??
The human eye response to light is logarithmic and differences of less than 2X would probably not be noticeable.
would the one drawing more burn out quicker because its same amount of lights but consuming more??

#### wayneh

Joined Sep 9, 2010
17,493
i looked up the pland for a 14 led array and it gave me 2 possible ways of doing it . im asking just for curiosity sake but i notice the both drew different amounts of power one says draws current of 140 mA from the source the other says draws current of 100mA from the source. is one brighter ?
Not necessarily. Impossible to tell without a schematic. If the person drawing the different configurations was careful, they each deliver the same mA to each LED and will therefore be the same brightness.
im assumeing if one is it is the one drawing more?
Not necessarily. Impossible to tell without a schematic.
would it be noticable if so?? would the one drawing more burn out quicker because its same amount of lights but consuming more??
The brightness of an LED is nearly linearly proportional to the current supplied the LED, so yes, one configuration might be brighter if it puts more current through the LEDs. The life of an LED is inversely proportional to the current, but I don't think it's anywhere near linear. So if an LED will last 1 year at 20mA, at 15mA it will last "forever".

Gaa!! dl324 beat me by seconds.

#### dl324

Joined Mar 30, 2015
16,722
Hopefully the OP will get the idea that EE types are detail oriented and a lack thereof leads one to fill in the blanks in not entirely predictable ways.

#### WBahn

Joined Mar 31, 2012
29,876
No. But it was just funny. Nothing about RMS, Peak or anything else, just Watts.
Oh, well "obviously" he was talking about "peak music power"!

I vaguely remember when that was the marketing buzz phrase for audio components.

#### scytzoh

Joined Nov 8, 2015
14
How can we possibly answer a question like this?

You don't give the plans for the two methods, so there is no way for anyone to guess how much of those currents is actually going through the LEDs.

I could make one circuit that had all of the LEDs in parallel with 10 mA going through each for a total of 140 mA and another circuit with the exact same LEDs in series with 100 mA going through each for a total of 140 mA. Which one will put out more light?

Perhaps one circuit has power going to a regulating circuit that doesn't go through any LEDs.
i think your over analyzeing this a tad it just a led power and resistor im posting something now

#### #12

Joined Nov 30, 2010
18,224
The whole point of that, "Wizard" is to design configurations in which every LED has the same amount of current, the same brightness, and the same life expectancy...so your basic answer is, "no".

#### mcgyvr

Joined Oct 15, 2009
5,394
Both solutions utilize the same 14 LEDs driven at the same current level..
Brightness is identical..

Once circuit is simply more "efficient" as its using the LEDs to drop the working voltage thus requiring the resistors to do less work (300mW vs 756mW)

#### kubeek

Joined Sep 20, 2005
5,793
You have circled the completely irrelevant number. Look at the ńumbers for "togetgher, all resistors dissipate x W" and "togetgher, all diodes dissipate x W".
Since in both cases diodes dissipate the same they will have the same brightness.

#### scytzoh

Joined Nov 8, 2015
14
Wow why does is seem like 80% of the responses are worded like I'm a fuckin idiot I'm new and trying to learn and news flash you learn by asking questions. And by getting responses back making the new person feel less than like duh you should know this its common knowlage.doesn't say much about your forum I'm 36 what if it were a 10 12 year old wanting to learn and you spoke to him like duh! The kid more than likely would leave and potentially not bother with this field that's I bit far fetched but stranded things have happens..at very least the kid would be reluctant to ask anything anymore for fear of looking stupid . what are those numbers then? That I circle d

#### scytzoh

Joined Nov 8, 2015
14
Both solutions utilize the same 14 LEDs driven at the same current level..
Brightness is identical..

Once circuit is simply more "efficient" as its using the LEDs to drop the working voltage thus requiring the resistors to do less work (300mW vs 756mW)
Thank you

#### mcgyvr

Joined Oct 15, 2009
5,394
In general most of us don't mean to come off harsh.. But many of us are Engineers or "technical" people and we rely on schematics and specifications which are better than a 1000 words..
Brush it off.. Do your best to answer the questions and provide the information as requested..