Need advice/help on building 3 flashlights(s11) with quad or triple ,but i cannot find the correct driver to use,i dont mind about modes ,all i need is 1 mode 100%
4x LUMINUS SST-10-IR infrared LED 850nm 940nm
Voltage : 1.2-2.0V
Max current : 1.5A
with 20mm copper DTP MCPCB for 4*3535 LED 2s2p
for this i guess a 7135 single driver with 3Amps will be ok,but i am not sure
Quad/triple paraller or 2s2p
LUMINUS SST-20-DR 660nm deep red LED
Voltage 2-2.6V
Current Max 2A
3v 8A buck driver maybe
Quad/triple paraller or 2s2p
LUMINUS SBT-10X-UV UVA 365nm LED
VF:3.8-3.9V,When the current rises to 3A, the voltage will reach about 4.5V.
OR
NVSU233B(T) 233B P9d22M 365nm UV LED Vf=3.6-4.0V
IF=max 1400mA
For the UV I’d go with tripple parallel and a fet driver. The leds will never see the full power as the fet/direct drive will only supply max 4.2V of the freshly charged battery minus the resistance of the system. So basically almost zero losses but also zero regulation meaning it will dim as the battery drains. A 21700 should last you quite a while especially if you use a linear+fet driver for the lower levels.
For IR emitters this is going to be crazy inefficient (as in under 40% driver efficiency), I might even worry about the 7135 chips burning up from absorbing so much excess voltage.
If you want 3-ish A drive current, I strongly suspect that the 2.5A red light driver will work. In theory you can also resistor-swap the 1.5A IR driver to increase the current, but I haven’t tried it yet and don’t know if it will overload the inductor.
The 7V is likely input voltage rating, which isn’t the whole story–you need to consider the input-output gap.
A 7135 chip is essentially a fancy resistor that burns off the excess voltage as heat. If you are driving an IR LED from a full cell, the power dissipated per chip is (4.2V-1.5V)*(0.35A) = 0.95W, which is well over the 0.7W threshold for requiring additional heatsinking, per page 4 of this datasheet.
2S2P would indeed be a great solution for 3V driver compatibility, provided that OP can either (i) source a MCPCB with this configuration or (ii) modify a MCPCB by cutting some traces and bridging some contacts.
Excellent! It just occurred to me to look this up a minute ago–somehow my brain initially discarded it because quads instinctively makes me think of Carclo-compatible MCPCBs. But this does indeed work, and one question on the product page mentions your application.
The quad setup has the mechanical dimensions of a single 7070 LED, so the 11mm opening S11 OP reflector could work, though it will make a very ugly beam with a giant hole in the middle. You will want some strong diffusion, like frosted tape on the lens.
i have that pcb and will use it for my infared setup ,i was afraid that the 6v boost drive will not be enough to feed the UV leds ,since they need 4v each.
