Originally Posted by mikefromgermany

Yes, Steve,
my intentions are to use the onboard SMD-Leds to trigger the much more powerful Nav-LEDS without influencing the really small 4-in-one PCB of my X4s. So it's really importantfor me to draw as less current as possible from the two LED-sockets - just to play it safe. I will not get any replacement PCB in near future for these quads - they will not be produced for months as a spare ....
-mike-

But do you need the original LED to stay in place?

Because if you don't, the opto-isolators are the safest way.

I don't know how comfortable you are with soldering / desoldering SMD
components, but you will have to tap in somewhere

Originally Posted by Steve_

But do you need the original LED to stay in place?

Because if you don't, the opto-isolators are the safest way.

I don't know how comfortable you are with soldering SMD components,
but you will have to tap in somewhere

SMD soldering - no problem - and yes, i want to let the leds stay in place - they are built in as eyes in the canopy.

hubsan x4 in wind (2 min 8 sec)

-mike-

Holy crap !! I had no idea how small these were.

You are brave if you want to take the iron to such a tiny board

Originally Posted by Steve_

Holy crap !! I had no idea how small these were.

You are brave if you want to take the iron to such a tiny board

the contacts of my SMD Nav-LEDs are just 1,5mm apart - soldered them to 0,1mm magnet wire (under a 10x magnifier...)
But these little beasts are worth it - d*** fast for their size - from zero to 300 yards in 5 seconds (vertical too with some other motors that draw 1,2 amps each at full throttle) - therefore the lights....
-mike-

Originally Posted by mikefromgermany

Yes, Steve,
my intentions are to use the onboard SMD-Leds to trigger the much more powerful Nav-LEDS without influencing the really small 4-in-one PCB of my X4s. So it's really importantfor me to draw as less current as possible from the two LED-sockets - just to play it safe. I will not get any replacement PCB in near future for these quads - they will not be produced for months as a spare ....
-mike-

If you really want to play it safe. Disconnect the stock leds and use that board to drive the opto. Then use the opto to drive all the leds, including the the stock ones

Originally Posted by minbari

If you really want to play it safe. Disconnect the stock leds and use that board to drive the opto. Then use the opto to drive all the leds, including the the stock ones

He just nailed it. This is by far the safest way to do it.

I never even thought of driving the stock LED's with the opto

Thanks again minbari for all the input

Steve,

Im getting old... after soldering 20 of these without glasses..... can't see a thing now....

Just to give you feedback

-mike-

Lol, well, they are designed to be surface mount.
Get over of those ring light magnifiers. Works great for me

Yup, they get pretty tiny.

My next project will be lights for the main blades, powered by a
tiny high value capacitor. I still need to see how many lights I can
run for 5 minutes. Maybe none, don't know yet.

Here's one I learned by accident - you can put LED's in series. I'll be darn!! Even more darn is if one LED is a blinker - the others will blink too.

captJac

Lol, yup. Led is just a diode. As long as your series voltage is high enough to turn all the leds on, then it works just fine.

As for the blinker, that is because there is an external IC that does the blinking (embedded in the case)

Little known fact, ALL diodes emit light. Most is in the ir spectrum and the black case blocks it