I’d like to build a light to mount on my tiny X5C quadcopter to chase the kangaroos out of the paddock at dusk.
I have plenty of 3.7v 800mAh 25c packs that I can use to power it.
I will use a dedicated battery for the light (not the flight battery).
In the past, I’ve used 12v LED strips on my RC planes, but on the quad, weight, size, and voltage are an issue.
I have zero experience with DIY flashlight stuff.
Please forgive the totally noob questions!
- Can I simply solder a battery plug to the CREE emitter and plug it in to the battery when I’m ready to fly?
- Is there something I can solder between the battery and CREE to prevent over discharging the battery?
- Flight times would be under 10 minutes, would I need to worry about heat? Light will be mounted in the open air.
What would be a good emitter to use? I’ll only be 5 metres off the ground, so flood would be best.
air circulation while flying should keep everything cool
I put a LED emitter outside and small driver board inside. (xp-g2 without any reflectors).
however, I did use the onboard battery.
edit: Please do us all a favor and upload a roo-chasing video when you are done! thanks! I have never seen a roo, let alone a drone chasing it. hahah :bigsmile:
I don’t have a switch or anything, the light is on when I am flying. since I mostly fly at dawn or at night I would need the light anyway. but it would be easy to put a switch in between.
The linked driver is nice and simple, seems ideal for your intended use. But I haven’t used it myself. The small chips are called 7135 and each limits the current to 350mA, all of them are connected in parallel so the current is added. How much current you get in the real world is also dependable from wiring resistances, led forward current and battery voltage. Of course with decreasing voltage current decreases.
For flashlights we often use these https://www.fasttech.com/products/0/10001683/1122302-8-amc7135-4-group-25-modes-led-flashlight-driver-c
They have 8x7135 and a tiny13 micocontroller to set different modes and under voltage behaviour.
Buy one tube of that if you simply want to glue the led star to some heatsink….maybe you have a aluminium frame which could be used…
how long is your flight time? I would choose a higher current which matches flighttime.
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Without optics the light will spread far, if you want more of a spotlight type you need a reflector.
Maybe the best would be to buy a cheap flashlight and just use the head mounted to the quad…
Yes, up to 45 mins, but in real life it will be bit less.
Ok, I figured out, that these 25C batteries can hold power quite well, so, If You need only 10 minutes per charge, You can use some 3A driver (like Werner recommended) with over discharge protection. usually tey are with multiple modes, but, maybe some flashing strobe can be useful for your situation
So do you need a spotlight which shines in one direction like the sk68 zoomed out or a wider beam? A XML without reflector is not too impressive…but I have no clue about chasing kangoroos(Until now I thought they would freeze if you shine a light on them…)
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I more thought about a 18650 driven flashlighthead but if you want to go really budget a old sk68 pill would work. If you want to use just the flashlight head with optic you would have to saw it in half because the whole housing is one piece.
They normally work with lithium cells but the resulting brightness is way less than a XML light with reflector…
A good standard 18650 flashlight costs 15-20$ and a cheap one from eBay can often be had <10$. This would be easy and good enough for every weather you might fly…
The convoy lights are very good quality and if you just solder a connector to the head you are ready. Just mount it with a piece of tape or so(maybe velcro) https://www.fasttech.com/product/1195010-convoy-s2-cree-xm-l-u2-1b-2-group-3-5-mode-edc
They have already a nanjg driver, reflector and an led build in. But I guess they are to good for your intended use, (but of course you could always use it as a nice flashlight again)
