Hypothetical: 10 LEDs VS 1 @ same current?

[kalel]

Let's imagine some run of the mill white 5mm LEDs. It could be anything from the cheap Chinese ones to high quality ones (I understand that the choice of LEDs might impact the result).

The question is whether or not connecting 10 LEDs in parallel and running them at low current (say 1mA) would yield a human-noticable higher light output than running a single LED at 10mA.

I also don't have any specific implementation in mind, I'm just curious if at least in theory, in low power consumption scenarios using more LEDs and running them at very low currents would make sense.

[Circlotron]

The LED manufacturer should provide a graph of luminous intensity vs current on the datasheet. That should provide enough information to answer your question.

[danadak]

The light response relatively linear with current -



Problem is LED to LED variation, paralleling them without using series Rs, ballasting, one in series with
each LED, could result in some LEDs with little or no current , others with high current.

Then there are optical issues, luminance on an area, size of area, shape......


Regards, Dana.

[GeorgeOfTheJungle]

The light response relatively linear with current -

Looking at this chart, it seems five leds driven @0.2 would be ~ 50% better than one driven @1.0, no?

[Zero999]

LEDs are generally more efficient, when run at lower current, assuming an SMPS is used. The light output is proportional to the current, but the forward voltage falls, as the current is reduced, therefore the LED consumes less power and is more efficient. If you're using a resistor or linear PSU, then the extra voltage drop is burnt as heat, but if it's a switched mode, then there will be some gains in efficiency.

[xibalban]

The LED manufacturer should provide a graph of luminous intensity vs current on the datasheet. That should provide enough information to answer your question.

He/she (quoted above) is right.

Depends on the LED type as you rightly mentioned in your first post. It all boils down to the efficiency of the LED that you choose to use. 10mA is drawn in both cases, and if there are equal amount of losses (heat loss mostly) in both the cases, the output (or brightness) should be the same.