mag leds current and what this might mean

yellow said:

Hi, Sorry if there is a tread on this topic. Dont remember reading one, and also was not able to find one, so ...

got my 2 AA and 3 AA Magleds. Inserted NiMhs and have the lights running for about an hour now.
measured current from the batts, which is
2 AA: 360 mA
3 AA: 700 mA
what does this mean (to me)?

I am used to work with Badboys and Luxeons, and thus I know: if using 3 NiMhs in series, the current from the batts is about equal than the current to the led, if using just 2 AAs, the ratio is about half.
So I "think", my 3 AA is getting what I am usually pumping into a Lux III (almost as much) and output is much less than it should be (but tint is good).
The 2 AA is way underdriven, but does a good job (except for the blueish tint)

Anybody else got these readings?

Click to expand...

yellow said:

Hi, Sorry if there is a tread on this topic. Dont remember reading one, and also was not able to find one, so ...

got my 2 AA and 3 AA Magleds. Inserted NiMhs and have the lights running for about an hour now.
measured current from the batts, which is
2 AA: 360 mA
3 AA: 700 mA
what does this mean (to me)?

I am used to work with Badboys and Luxeons, and thus I know: if using 3 NiMhs in series, the current from the batts is about equal than the current to the led, if using just 2 AAs, the ratio is about half.
So I "think", my 3 AA is getting what I am usually pumping into a Lux III (almost as much) and output is much less than it should be (but tint is good).
The 2 AA is way underdriven, but does a good job (except for the blueish tint)

Anybody else got these readings?

Click to expand...

Nereus said:

I have no experience in Magleds but my Minimag modded with Badboy NG750 and Lux3 pulls 1.2 amps from the nimhs. So if you are seeing roughly 0,4 amps from two nimhs, that's one third of my figure which provides the led with 750 ma. Dividing 750 by 3 gets 250 mA to your led.

Remember, this is a very rough estimate but in any case your ~250 mA output current to the led seems to be a very low. There may be a thermal sensor which decreases current when led gets hot. You can find one in 2D-6D magleds, but I dont know if this is the case with AA Mags as well. If you can measure substantially higher input amps immediatly after turning the (cooled) mag on, there might be a thermal sensor that have dropped the input current to 360 mA.

-N

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adnj said:

I don't understand... If the batteries are in series, then the current is constant thoughout bout V is not (could be slight/significant differences due to battery condition). Total current may not necessarily be supplied to the LED unless it is directly driven, which it is not. How much current is being dumped by the regulator circuits that are being used?

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