Aha, I was wondering what kind of current that opto needed.
Usually with LEDs they clearly state prefered operating current.
With a 82 ohm resistor it would drop it to 40mA or something,
but if you say prefered current is 10mA then 220ohm makes more sense indeed.
I'll determine which end is positive and then put a resistor on that side.
Unfortunately my current sensing multimeter has broken down, and I only have a dinky backup one.
Luckily I do have a whole slew of common resistors to try, Is there a safe bet value I could start with?
Actually, forget it, no need to get so freaking hostile, bud.
I'm just here trying to learn by doing, because I don't have the time to pick it up as a profession.
If I had a degree in electronics of any kind, I wouldn't be here being screamed at by you.
So if you have a problem helping a hobbyist beginner, just sod off?