New member here looking for recommendations. I am designing a very specific search and rescue tool specifically for an Autel Evo 2 Dual drone (which has Flir Thermal camera) Currently no really good option exists for a search light for this drone. Ive designed a saddle that can use a variety of lighting options but Im specifically looking for no less than 1000 Lumen (or more would be great) in the smallest and lightest possible package. Since this will be attached to a drone, Weight is key so I need to maximize the lumens per gram of total weigh on the airframe.
All told, I want max. beam throw, no less than a 1000 lumens, the lightest package possible. (and I dont want turbo step down since I cant control the flashlight when the drone is in the air ) so I want max lumens for the entire run time. Also NOT wanting proprietary batteries but rather off the shelf common batteries. Im not as worried about battery life since the drone itself will need to return to base each half hour for a new battery any way so popping new batteries in the lights is not a problem. The first prototype I made, I used 2 Nitecore C11 lights since I had them but I know I can do better. Here is a video of proto #1. My total payload is 10 lumens per gram of weight on the air frame. I think I can find a better light option so Im here looking for recommendations.
That’s a fun project. I came up with a rough solution which would produce ~2600 lumens and weigh ~130g (without your saddle), but it is bare-bones and would require some engineering solutions to attach various things. It consists of one high density 21700 cell (samsung G50), two SST40 LEDs along with two reflectors and two heat sinks. I can give more details later. Each SST40 would be driven at 4A. That 21700 cell would power the lights for just over 30 min.
Comparing to your 2x EC11 solution (1800lumens and 139g for just lights without saddle) my solution is better, but not that much better. However, looking more closely at the specs of the EC11, it seems there is some discrepancy. 900 out-the-front lumens would require about 1050 LED lumens which would require about 8W. Power it for a duration of 30min would require an energy of 4Wh not considering driver losses. But the 700mAh 18350 cell has only about 2.45Wh. There is most likely a stepdown which means you aren’t getting 900 lumens for 30 min.
Step 1 is find an LED with highest possible efficiency.
Underpowering LEDs typically leads to higher lm/W so a large LED like an XHP70-2 driven at low currents can get over 200lm/W while still outputting over 1000lm
Then you need an efficient driver, which I don’t have much information on, but you can find some efficiency tests if you look for them.
Finally you need a high energy to weight ratio battery, and the top ones are 18650 or 21700 Li-ION cells.
LG M50 or samsung 50E is what I would choose.
With this combo you could have over 3 hours of runtime at 1000 lumen output, or 6000 lumens for half an hour if you use mutiple LEDs.
Two thoughts.
Enderman is correct, an under driven led would be best, requiring less heat sinking and give the option of driving it harder in certain situations.
Why not save the weight of reflectors and use aspheric? This could also be adjusted to the give a tight spot or flood a large area.
Guys, these terms are all greek to me. Im looking to see if such a EDC (or other) light currently exists for this need or if I need to have somebody build this for the need. Im in not position to make this.
You can’t just look at lumens. You can have a light with a tighter hot spot with less lumens that out throws something with more lumens and a wider beam pattern. Look at lumintop FW1A with the short 18350 tube. Not the PRO model. Ounce for ounce thats pretty good throw. And yes it will step down but even when it steps down it’s going to out throw what you have now.
Im a flashlight dummy but after a very fast ramp down, its a 300 lumen light? Am I correct? Im looking for 1000 lumens continuous with no ramp down or after ramp down. Perhaps what I want does not exist. My 900 lumen nightcore ec11 seems to be 900 lumens for 30 minutes.
yes that was one of the worst option I looked at so far. That only produces 3.4 lumens per gram of weight. My first proto is over 10 lumens per gram of weight using the nitecore ec11.
I wonder if I never noticed it (stepdown) since Ive only used it in sub freezing temps so it never got hot so it never stepped down Is that possible/likely?
[quote My 900 lumen nightcore ec11 seems to be 900 lumens for 30 minutes.[/quote]
Turn on one for 5 minutes and then turn on the other one and you’ll see the first one has dropped off significantly. Lumintop FW1A. Not the pro model. With the 18650 it’ll probably put out double your current lumens and double the throw for 30 minutes.
Its truly a step down free light. Flying around in the winter might be okay, but the thing is going to get HOT without airflow or in high ambient temps. Also, a 21700 cell is going to add 70g. Don’t know if you are keeping track of that…
