Vf is a problem with XHP35 and 12V supply. i’ve never used a boost driver and don’t have a schematic for one. i’ve also heard they’re not a good idea in high current applications.
what would be the next best choice after XHP35? are none of the xp-g3 style parts strong enough?
could someone rank the LEDs in order of preference for long range power?
still open to ideas.
thanks.
there is nothing wrong with properly selected boost driver. but in your case vf and supply match, you could be fine with linear driver. l flex from task led should do the job, or any other linear driver with low voltage drop.
in theory you can direct drive, or a resistor. try 1 xhp see how it works,
some outboard charging systems produce up to 16volts. that worries me with a linear driver. also most boats have 24v and 36v available and most people think hot is hot. this light has to be idiot proof.
what do you think?
thanks
then i would use 6 xhp35, 2 strings, each has 3 leds in series, each string has it own driver, i’d use flexblock 700ma, it is boost buck driver, led supply sells those.
You can get cheap, small, buck and boost drivers all over amazon and aliexpress for under $10. You can set the current control to your max and use the voltage limit for control, or the other way. Good idea to replace the onboard pots with a nice knob, for convenience and because the onboard pots are likely junk and failure may ruin your light.
For a practical light like this where you don't need to cram the driver into a 15mm space, a controllable buck or boost seems great. Then you get analog control, which isn't bad.
i want to build my own drivers onto the same board with LEDs.
what do think about 6 XP-L with 2 PAM2863 drivers running at 2A or 4 XP-L running at 3A?
at what current do i need DTP?
thanks
at 3A DTP has a clear benefit to gain lumens as the LED stays cooler
with DTP you can easily get to 4.5A without to much lumens/W efficiency loss compared to 3A on a cheap star
DTP boards pay for themselves, as you can push the current per LED and reduce the number of LEDs significantly
basically XML footprint gain less than XPL from DTP as the surface of the thermal pad is bigger
red and blue line are bad aluminum stars as you find em on so many shops
here is a comparism from XML with different MCPCBs, for XPL footprint the curves should be more significant
and he damaged the LED on a cheap star
My mistake.. edited. I see you made a link this time. As links break though I think it's still worth pointing out (and proper etiquette) that these are djozz's plots, and great work it is.
using cree’s lumen calculator, it seems 6 XP-G3 or XP-L2 driven at 2A would generate about 5000 lumen. G3s are cheaper and lumens are very close to L2s so G3s seem to be best choice to my simple mind. am i right?
are DTP boards necessary for XPs driven at 2A?
thanks
i really like the cree lumen calculator. thanks Lexel.