Dangerous operation current test on Petzl MYO-RXP

leowood · Jun 8, 2010

I am new here come from China, its my first thread here.
I just test my headlamps Ptezl MYO-RXP with a HP power supplier 6632A
I was horrified to discover that the headlamps input current is up to 1.3A when I set the voltage 4.5v, its mean input power is 5.85w, the DC-DC efficiency should not less than 85%, so the SSC led will take about 5w+ power, the dissipation power exceed the abosolute characteritistics for sure...

so my question is, if we use li battery like Energizer batteries L91, it will burn out the headlamp or not? :sick2:

Szemhazai · Jun 9, 2010

In real conditions after connecting load the voltage of the source drops quickly...

From brand new batteries :

Code:

        V-in   I-In     P-In   V-led  I-led    P-led  Eff. 
high    3,65   0,8215   3,00   3,28   0,8458   2,77   92,5%
mid     4,28   0,3095   1,32   3,06   0,3086   0,91   69,0%
low     4,44   0,1709   0,76   2,96   0,1640   0,46   61,2%
boost   3,63   0,8522   3,09   3,29   0,8608   2,83   91,5%

From freshly charged NIMH's

Code:

        V-in   I-In     P-In   V-led  I-led    P-led  Eff. 
high    3,50   0,7431   2,60   3,25   0,7183   2,33   89,8%
mid     3,84   0,3070   1,18   3,05   0,3026   0,92   78,3%
low     3,97   0,1590   0,63   2,96   0,1593   0,47   74,7%
boost   3,45   0,7562   2,61   3,26   0,7483   2,44   93,5%

So.... get real

leowood · Jun 9, 2010

Thanks Szemhazai, I have already read your thread, it's very helpful...so petzl design the boost circult base on 3.7v around not 4.5v, I am wondering if the boost circuit is directy driving mode(connect the LED to battery,enable the boost function will bypass the PWM circuit)?

Dangerous operation current test on Petzl MYO-RXP

leowood

Newly Enlightened

Szemhazai

Enlightened

leowood

Newly Enlightened

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