In fact, based on this, if I go even to a 70ohm resistor, I will be down to the minimum voltage levels. It would appear to me that even a 100ohm resistor would remove too much and would not trip the optoisolator? Is this right? It looks that way on paper, but doesn't "feel" right.
60mA is the maximum forward current rating of the optoisolator. It will work at much lower currents, depending on its current transfer ration and how much current the flash unit sources. The Arduino output pins are rated at only 40mA. I would design for 10mA (if that is enough to trigger the flash) or 20mA.
I may be getting too deep here, but what's the way to tell how low is too low? My assumption is the only point of the output from the Arduino is the light the LED within in the optoisolator so the sensor within is able to recognize the condition and then close the other side of the circuit. Right? I guess I don't understand how the flash values affect this.
Use a MOC3020 optotriac.Six pin DIL package, 7.5kV of isolation, you drive it like a LED (10 to 15mA), switches up to 400V, no polarity issues on the output.You can trigger them with pulses of a microsecond or less.
Quote from: AWOL on Jul 24, 2012, 02:01 pmUse a MOC3020 optotriac.Six pin DIL package, 7.5kV of isolation, you drive it like a LED (10 to 15mA), switches up to 400V, no polarity issues on the output.You can trigger them with pulses of a microsecond or less.Isn't there a risk that the triac would stay on once fired? Depending on how much current the flash unit sources.
Yes, pin 1 is on the side with the groove.