Using the below schematic, why was the value of the 22Ω resistor chosen?
My first instinct would be to think that it's for limiting current, however looking through the datasheet for the MOCxxxx isolators, I'm not sure which parameter would tell me how much current should be used and it seems to be a little more complicated to derive the output circuit formulas used in the design.
Also I could not find out whether the output current from the zero crossing circuit would be enough for the gate of the triac controlling the load.
My first instinct would be to think that it's for limiting current, however looking through the datasheet for the MOCxxxx isolators, I'm not sure which parameter would tell me how much current should be used and it seems to be a little more complicated to derive the output circuit formulas used in the design.
Also I could not find out whether the output current from the zero crossing circuit would be enough for the gate of the triac controlling the load.