I never said about using anything other than 5V from the USB port. Although USB PD or USB QC would be very nice to have, it would probably be unrealistic for a flashlight driver. All I am asking for is for the driver being able to run without battery just using the 5V typically supplied by USB. This was already possible with the M4U flashlight (I am currently using two M4U with no battery inside, just powering them using USB). The problem with the M4U is that without a battery it does not run at full power. I have noted the power consumption over the USB cable and it never reaches even 1A at 5V. This means that the driver chooses to not draw enough current at 5V for the light to operate at full power. All I am asking is for the new driver to be able to run the GT-FC40 without battery at maximum power or whatever the USB cable can provide at 5V. That would be 10W power at 2A over 5V or 15W at 3A over 5V.
Given that the driver already needs to buck the 5V USB voltage to charge a cell (when present) and to boost the 5V USB voltage to power the emitter, what I am asking is no different, so there should be no fundamental design changes.
Ah, sorry I interpreted your “full power” as being running the emitter near full capability, not as utilizing the full standard available USB power, that does sound less complex!
(All I am asking is for the new driver to be able to run the GT-FC40 without battery at maximum power or whatever the USB cable can provide at 5V. That would be 10W power at 2A over 5V or 15W at 3A over 5V.)
I’d mount one to the handlebars of my ATV and enduro bike if that was possible.
Can an Osram W1 Red be driven with an 8x7135 biscotti driver? I got an RGB C8+ set and it bugs me that the red has a different UI. I’m considering swapping in a spare biscotti driver I have but I don’t want to burn out the LED or anything.
These are about as durable as the white emitters but they derate a little with heat. Datasheet rates 2.5A max with 3.3A pulse, plots look good like the white so it should be fine as long as you keep it in normal thermal cutoffs (80°C is a killer at 2.5A but…). Actually pretty impressive for a color emitter. That said, I don’t know how much is to be gained above 2.5A but it shouldn’t hurt it at all…8x7135 is usually around 2.7-2.8 anyway with the 350mA chips and didn’t increase much with the 380mA.
Edit: I just opened up the light and I see this 4R7 thing and some red glue looking stuff. Is that a buck converter and potting compound perhaps? I don’t see the same component or glue on my 5A linear drivers in my Green and Blue C8+’s. If so, then switching to a 7135x8 driver should produce significantly more heat, right?
It’s an inductor…not sure about the driver particulars there and Simon’s product pages are invisible for awhile yet. The coating is not potting compound…it’s a “conformal coating” which is kind of like solder mask, just used to help protect against oxidation and dust, potential shorts, etc. It’s a nice professional touch although the way they often do it with cheap electronics is kinda half-arsed and at times doesn’t make logical sense, but…better than nothing (until you want to desolder things). The 7135 will usually run warmer until voltage drops…they do their job but not efficiently.
It’ll work, but doesn’t run very well. It operates at a higher VF so you’ll get less efficiency. You lose 40% output very quickly. Stick with what’s in it
This is with the 8*7135 biscotti driver. Used this in my first lot of stock when I first started using the Osram red. I stopped after running this test.
This must be one of the most beautiful beam shots Ive ever seen. Your use of a wall corner to mix 90 degree beam and color convergence was brilliant. If its a Photoshop, it certainly fooled me. Well done!