This is my first circuit build project, so go easy and speak slowly lol
I fly a powered paraglider, and to comply with FAA regulations, I require an anti-collision strobe light that has 3 mile viability. I would like to build a five-sided omni-directional LED "cube" using (5x) CREE XHP50.2 emitter. When active, the strobe will flash twice, then pause before repeating. The flashing logic is a topic for another time. The circuit design is the focus of this post...
I would like to run all five of them in parallel. My general thought would be to use the PWM output pin to trigger the base pin of a 10amp NPN transistor and create five simple current-limiting resistor circuits in parallel (one for each LED) on the emitter/collector pins. this may be an awful idea and I'm sure I'm missing some of the finer details, but does this sound like I'm heading in the correct direction? This will be battery powered, so circuit efficiency is a factor, but I'm looking to keep this as simple as possible at the same time.
Any help would be greatly appreciated! Even a napkin drawing would be very helpful!
You don't NEED all the LEDs to flash at the same instance then, right?
You picked 5 LEDs. If you arrange them in a circle that's 72 degrees each, which is actually pretty good. The Cree specs shows about 85% intensity at +- 35 degrees.
Do you have a top of tailfin location that you can use for single-location anti-collision light? Is anti-collision all you need on your type of aircraft?
Thank you all for the quick responses. To clarify, what I mean by "double flash", and the reason I am not using a 555 timer circuit or something like that that is because I am trying to achieve a non-symmetrical flash pattern (2 X 20ms flashes per 1 second). From my research and limited understanding, it seemed easier to write a program to achieve the exact flash sequence, rather than try to create a logic board to accomplish the same task. It sees like it can be achieved in a smaller form factor too that way. There are some future coding projects that I would like to explode if I have the controller at my disposal (such as using an accelerometer to detect a crash event and automatically trigger an S.O.S. strobe flash pattern), so if possible, would like to build around the assumption that it will be interfacing with a I/O pin (whichever one is the most appropriate for this application).
Essentially, this is what I am trying to make, except with more, and much higher powered, LEDs.
@terryking228: As far as LED configuration goes, I'm picturing a cube with LEDs on 5 of the 6 sides (the bottom side will be used for mounting). See link to image for example of LED configuration and what a powered paraglider looks like
I'm picturing a cube with LEDs on 5 of the 6 sides
OK, I was wondering about the flash duration you expected.
MIT Says 13 ms is almost enough to see an image. So 20 ms seems right.
What I meant about timing was, you MIGHT not turn all the LEDs on at once, but sequence them. 5 x 20 ms would be 100 ms for a "flash" and it MIGHT actually be effective visually, and the current drawn would be that of 1 LED at a time. Total power is the same of course.
Nice thing about Arduino is you can try this all out in software.
