XM-L driver question

[muddrunner198]

I did a search and could not find the exact answer IM lookin for. I am looking for a driver for my XM-L 6V battery project. I stumbled across a driver that had an output of 2800ma and an output voltage of 16-18 volts. It said its for an XML. wouldnt a 16v output voltage burn up an XML, and what would be a good driver for my 6V source.
Thanks Dave

 

[archer6817j]

I use a 2.8A driver from shiningbeam. Takes up to 6v input but no more than that.

 

[videoman]

Output voltage of 16 to 18 volts?? either a typo error meaning they probably meant INPUT max voltage or perhaps it is a BOOST driver capable up to those voltages.If I had a single XM-L to power up from a 6 volt source at 2.8 amps, obviously a BUCK driver would be the one. I have had great sucess by paralelling 2 DX drivers at $2 apiece SKU #26110 to give out a healthy 2.4 amps with a wide V in up to 18 volts. A little underdriving the led but in a way good for low heat and verry little difference in apparent light output compared to 2.8A.

 

[Lumencraft (Matt)]

Hey mudd,

Welcome to CPF.

Could you give a little more detail about the light you are building? When you say a 6 V power source do you mean 2 primary lithiums? Or are we talking like a 6V lead acid battery? What size host?

 

[Harold_B]

muddrunner198 - If Videoman is correct and its 2.8A out at 16-18VDC input then I am very interested to know where you found that. Can you post a link? It would be much appreciated.

Harold

 

[Curt R]

Output voltage is not a problem as long as it is above the
voltage drop across the LED, with the Cree XML that is about
2.8 to 3.3 volts. The only thing that burns out an LED is the
amount of current going through it. If the power supply is
limited to 2.8 amps and the LED is correctly heat sinked there
is no harm to the LED, even if the output voltage is 200. If
the output voltage is less than the drop across the LED, a
power supply capable of 200 Amps of output will still not harm
the LED. The LED acts as a resistor when it heats up and can
allow more voltage and then more current to flow through the
LED.:poof: if the power supply is not regulated.

Curt

 

[Lumencraft (Matt)]

I am guessing this is the driver ( or at least a variant) we are talking about?

 

[recDNA]

I wonder why that driver is so HUGE? I was looking for one small enough for a P60

 

[bbawkon]

Output voltage is not a problem as long as it is above the
voltage drop across the LED, with the Cree XML that is about
2.8 to 3.3 volts. The only thing that burns out an LED is the
amount of current going through it. If the power supply is
limited to 2.8 amps and the LED is correctly heat sinked there
is no harm to the LED, even if the output voltage is 200. If
the output voltage is less than the drop across the LED, a
power supply capable of 200 Amps of output will still not harm
the LED. The LED acts as a resistor when it heats up and can
allow more voltage and then more current to flow through the
LED.:poof: if the power supply is not regulated.

Curt

LED's don't generally act as resistors.. They act as Diodes.. hence their name... It is diodes that change their voltage drop with relation to temperature, not resistors. Resistors change their voltage drop with relation to current.

 

[Norm]

Moved.
Norm