the drivers that you’re looking at are for 12V desktop light bulbs that typically have a single LED. So they buck the voltage down from 12V to 3.5V or so. The 1W driver should then supply ~330-350mA, which fits.
Either way, if you want to drive a 12V LED from a 3S pack you can’t use a buck driver (Vin > Vf) and might not be able to use a boost driver with a 11.1V pack.
What’s the application? There might be easier ways to skin the cat you have in mind
Those drivers are buck mode drivers. Their ouput voltage must be less than the input voltage minus a couple of volts. That LED is a 3x3 array of LEDs. It needs around 10V to drive it to full power. A 4x18650 pack should work well with those drivers.
CURRENT DRAW 330 mA
INPUT TYPE 12V
POWER CONSUMPTION 1 W
So input is 12V but what is missing in description is output is about 3.5V which is typical for LEDs, hence 3.5 * 0.33 is about 1W
Then I am guessing this LED I found is actually 3 LED elements in series that need about 12V, something like that. Got it. Then I am not sure how to drive it if all drivers output 3.5V
I am making a portable light for general room lighting, so don’t need a reflector.
Since a 3s pack produces about 12V I thought using a 12V input LED would be the best match.
So I simply need a driver to regulate the current, 2 levels around 1A and another lower around 0.1A-0.3A
Or am I looking for some other device to regulate current? Or different driver type that outputs 12V?
Another possibility is simply use 3 separate normal LEDs with individual drivers. I have a 4 way switch so I can simply wire them in series; in each switch position bring additional LED into circuit in series. Something like that. Is that the reason why some drivers have AxB spec, like this:
Those are constant current drivers. They will output whatever voltage is needed to cause 350 mA or 1A to flow into the LED. They can output voltages up to the input voltage minus around 2 volts. Thos particular drivers have a bridge rectifier and filter cap on the input. You can drive them with either AC or DC. That 10W one is good to about 30V in.
A 3S pack could output 9V if it is near empty. You need 4S to have enough headroom to drive the array.
Because I am trying to use about 10W, 1A from 3 or 4 18650 cells.
Maybe the latest XML could handle it but it would be pushing it too hard, no?
I have a 3 x XML light using 2 18650 cells at 2A and 4A modes. My cells are recycled from laptop packs, so 1A is probably much more realistic. Better ones can handle 2A but wouldn’t last.
I suppose I could push 1A for about 4W max into a single XML or something like that.
Hmmmm, maybe that is the way to go. Simpler.
I will have to check what is the max power rating for XML. I though I read some place it is 1A-2A range.
I am having a hard time finding MT-G2. Also I am trying to keep it a low budget little experiment.
I can find XML T6 on usual sites like dx and ft, etc.
I’ve tried a couple 12V/10W emitters, similar to what you linked, but from DX.
IMO, the only reason to use them instead of Cree emitters (since they offer emitters with 3.x, 6, 9, 12, an even higher Vf) is because they’re very floody
sometimes that’s useful, particularly in an area type light, like say lighting a yard, dock, or in your case, a room.
xm-l is pretty floody though, but if lumens/Watt is more important than a very floody beam profile, go with xm-l, since they’re a bit more efficient.
using a single 12V emitter could simplify the project, if you figure out the right driver
here’s a good reference for finding them. it isn’t all inclusive, but if you email Ian (he’s also a member here), he does update the info
