Hello everyone, as the title suggests I would like to build a led light like this but a little bigger --> https://www.ulanzi.com/collections/led-video-light/products/ulanzi-vl61-rgb-fill-light . ..for use in photography. I'd like to use 5 SST20 4000K (high cri, 95+) leds but I lack information regarding the combination of driver(s) and battery (number of batteries in series or parallel). Thank you
there is more ways than one. depends what you need, do you need it to be dimmable? will your batteries be sealed inside? or replaceable? will you need an option to hook it to a wired power source? how long do you need batteries to last?
leds can be wired in series or parallel, with either boost driver or a linear one, as well as individually with each driven by its own driver. cells can be wired in series or parallel, however series wiring requires balance charging by a balance charger, or you can use a PCB with balance function, and charge it with simple 2 wire charger, you can wire cells in parallel, and charge them via usb cable. if you go with replaceable set up, you do not need to wire cells for charging, you can do it outside individually.
each set up has its pluses and minuses.
IF i wanted to do something like that, i'd use power tools batteries, of any brand, they already have protection circuits, already assembled in a housing, they are charged by fast chargers, and you can replace a dead battery with a new one in seconds. they are 18-24v so you can use a buck driver. 5 leds means you'll need 15v, so vast majority of batteries already give you enough overhead voltage for buck driver to work, buck drivers are simple, and there are plenty of them on sale, If you own and use power tools, you already have batteries.
Thanks for the reply!
I start with the dimensions and features:
- size: 9 cm x 9 cm and 3.5 cm deep;
- dimmable with wheel;
- 80 minutes at maximum brightness (about 3000 lumens).
What is the best strategy to have reduced dimensions and weight and have greater longevity?
I wish it had removable 18650 batteries (is 3 batteries ok?).
n° 5-6-7 SST20 4000k leds are they enough?
To have greater longevity and simplicity, is the best thing to have the LEDs with their own driver and batteries in parallel?
If this is the case is it possible to dim all the LEDs with a single knob?
I have a 3d printer and I'm learning to print simple objects built by me. if the project is feasible I already know that I will have a lot of fun building with you an object useful to me (photography enthusiast) and making the knowledge available to others to build a similar tool.
Thanks
I did something similar for my emergency light connected to a car battery: a couple of dollars PMW for electric motors connected directly to the LEDs and to the battery.
In total I spent 2 dollars, everything else I had and it works great.
The flickering is not visible to the naked eye, but if you want I can make a measurement with the opple light master 3.
I know it’s not budget and you said you want to build one, but for all the mucking around you could just get one of these FireflyLite NOV-Mu 21*Nichia E21A Indoor & Camping Photograph Flashlight
- I have one and they are one of the most underrated floody mules you can get IMO and the beam is awesome with a CRI of 98. you get about 2500 lumens on high, and 5000ish on turbo.
The one you showed a link to would be lucky if it puts out more than 250 lumens (but I doubt it) in this video it looks only good for close ups and you would need multiple to have the output.
Heck you could even go with a E12C as they are cheaper/newer/more efficient with a ton of output but bigger, you could put a diffuser on it for smooth even light.