Tripple led power distribution question

lightseeker2009

Enlightened
Joined
Jul 29, 2009
Messages
681
I've got a Osram Crosser 3-led spotlight. I have asked about a simmular question before but have never finished the project. Now its time. I thought it's better to start a new thread.

Firstly, it seems the three led's are powered in parallel. The main wires coming from the driver is connected to a small board that distributes the led's power in parallel. The main wire is 2.47 volt. So is the voltage if measured over every of the three led's.
I've learned that a led driver puts out a constant current. Is this statement true? If this is true, will I overpower one led if I disconnect the other two in order to save power? My thinking is that the current devided by three normally will now all go to the single led. The voltage will stay the same, correct?

Will I shorthen the life of the single led if I disconnect the other two? Any assistance would be really appreciated, thanks
 

PeterH

Newly Enlightened
Joined
Aug 31, 2010
Messages
52
To first approximation correct. The voltage will increase a bit. Disconnecting 2 LEDs while doing nothing to the driver won't decrease power consumption. And given the treatment I've seen LEDs get in flashlights in base configuration, the remaining LED would be overdriven.

If you want to reduce power consumption, a change will be needed to the driver, likely on the current sense resistor. This may shift the color balance of the light produced.
 

lightseeker2009

Enlightened
Joined
Jul 29, 2009
Messages
681
Thanks for responding. I almost did it but decided to wait for a response. The leds does not draw much power, less than .3 amps. Can a potensiometer be used to adjust brightness?
 
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