for a customer I made once a MCPCB with driver circuitry on it
I used 2 0.47 Ohms in parallel for an XPL-Hi that pretty muh nailed the current to 3A tops from two high drain 18650 in parallel
Surprizingly the resistors stayed very very cool, I could have probably gone with lower than 2 0.75W ones
the main criteria limiting them is heat and they are usually rated on x mm² of PCB to dissipate the rated power
in general driving those LEDs close to their physical limits in parallel is not a good idea
for a customer I made once a MCPCB with driver circuitry on it
I used 2 0.47 Ohms in parallel for an XPL-Hi that pretty muh nailed the current to 3A tops from two high drain 18650 in parallel
Surprizingly the resistors stayed very very cool, I could have probably gone with lower than 2 0.75W ones
the main criteria limiting them is heat and they are usually rated on x mm² of PCB to dissipate the rated power
in general driving those LEDs close to their physical limits in parallel is not a good idea
Oh yeah, I forgot that mounting the resistors to the mcpcb helps dissipate heat much better than if they were mounted on a driver. Duh.
—
Texas Ace Lumen Tube and JoshK Sphere calibrated with Maukka lights
The basic data I cannot figure out is the manufacturer’s stuff (XHP50 > 6V 3A – 12V1.5A) I must be dumb, but I cannot figure out that Amp/V business…
I can help with that last part.
The xhp50 and xhp70 are available in both 6 volt and 12 volt versions. Each emitter has 4 tiny dies which are 3V each.
So the 12 volt version have all 4 dies wired in series.
The 6 volt versions have the dies wired 2 in parallel and those 2 in series.
So 3 amps at 6 volts equals 18 watts.
1.5 amp at 12 volts also equals 18 watts.
Same power levels.
_Ohms law states volts X amps = watts
_
Make sense?
Actually Ohms law says amps times resistance equals voltage…It is watts law that says volts times amps equals watts. I know it is nit picky, but a guy named Georg Ohm came up with Ohms law, and Watts law is named after James Watt, an inventor. Though similar, it is 2 separate laws.
Actually Ohms law says amps times resistance equals voltage…It is watts law that says volts times amps equals watts. I know it is nit picky, but a guy named Georg Ohm came up with Ohms law, and Watts law is named after James Watt, an inventor. Though similar, it is 2 separate laws.
Fixed.
—
Texas Ace Lumen Tube and JoshK Sphere calibrated with Maukka lights
for a customer I made once a MCPCB with driver circuitry on it
I used 2 0.47 Ohms in parallel for an XPL-Hi that pretty muh nailed the current to 3A tops from two high drain 18650 in parallel
Surprizingly the resistors stayed very very cool, I could have probably gone with lower than 2 0.75W ones
the main criteria limiting them is heat and they are usually rated on x mm² of PCB to dissipate the rated power
in general driving those LEDs close to their physical limits in parallel is not a good idea
[Reviews] Miboxer C4-12, C2-4k+6k, C2, C4 / Astrolux K1, MF01, MF02, S42, K01, TI3A / BLF Q8 / Kalrus G35, XT11GT / Nitefox UT20 / Niwalker BK-FA30S / Sofirn SF36, SP35 / Imalent DM21TW / Wuben I333 / Ravemen PR1200 / CL06 lantern / Xanes headlamp
[Mods] Skilhunt H03 short / Klarus XT11GT, XT12GTS / Zebralight SC50+ / Imalent DM21TW / colorful anodisation
[Sale]
Drivers: overview of sizes and types
DD+AMC based drivers Anduril or Bistro OTSM 12-24mm, S42, 24-30mm L6, Q8, MF01(S), MT03, TN42
Anduril or Bistro 8A buck driver for 20-30mm, MF01/02/04, TN40/42, Lumintop GT, MT09R
UVC and UVC+UVA drivers
programming key
Remote switch tail DD board with FET
Aux boards:
Emisar D1, D1S, D4, D4S, D18, Lumintop FW3A, Fireflies ROT66, Astrolux MF01, Tail boards like S2+
Oh yeah, I forgot that mounting the resistors to the mcpcb helps dissipate heat much better than if they were mounted on a driver. Duh.
Texas Ace Lumen Tube and JoshK Sphere calibrated with Maukka lights
Click this to go to signature links. I'm still around, just not reading many new threads.
Actually Ohms law says amps times resistance equals voltage…It is watts law that says volts times amps equals watts. I know it is nit picky, but a guy named Georg Ohm came up with Ohms law, and Watts law is named after James Watt, an inventor. Though similar, it is 2 separate laws.
Fixed.
Texas Ace Lumen Tube and JoshK Sphere calibrated with Maukka lights
Click this to go to signature links. I'm still around, just not reading many new threads.
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