I have a couple strobes that are FAA compliant in the sense you can see them at dusk/night 3+ miles away.
But my question is regarding daytime flying - extending the distance I can see the position of the drone during the day.
So I’m looking for two solutions:
For drones that are 200-250 grams (needing a very lightweight solution to stay under 250g), and
For drones that are 1500-3000 grams (where the light(s) can weigh quite a bit - 200g or more? 500g?
I’m looking at both LED’s and LED “arrays” as well as flashlights with a “long throw” (or course realizing the “long throw” will narrow the beam, but that’s probably a trade-off I’m willing to make for longer distances).
For Dyi and low cost, I use the 1W (350mA) LEDs on the ALU pcb heatsink. After many testings, I prefer green in the front and red in the rear (ymmv, haha). I series 3 LEDs in series and use a resistor to limit the current to ~200mA (they don’t seem much brighter for the extra current). I place one on the bottom of the arm (facing down) and two on top of the arm (in a teepee or upside down V). Visibility is very good from all orientations. And sometimes I add 3 blue LEDs on the bottom as I do flip and roll a lot. The 1W LEDs are dirt cheap with the ALU pcb, about $7 for 50pcs. The whole thing can be plugged into the balance connector as it’s under 1A. And a simple 555 and fet will pulse or strobe if you like.
I mentioned adding a current limit resistor, here is a table I made showing the voltage drop on each color of the LEDs at three different currents. This will give you the total series string voltage, minus this from your ending flight voltage, to get your resistor voltage, divide this by the led current you want to run and this is your resistor in ohms needed. You can use a little higher or lower value. Be sure to get the property rated wattage resistor.
You can pulse these LEDs at a much higher current (strobe mode) if the duration is short.
