Isnt the FET gate same as opto's emitter, since the two are connected?
Do you mean drain by collector?
I mean:-
The emitters of the optos should be connected to ground, the -ve of your 24V source and the FET gates should be connected to the collector of the FETs.
Do you mean to the - of the 24V?
Yes.
But that makes all three optos connected, if one opens all three FETs open.
No. Each FET gate should be connected to the collector. Each emitter should be connected to the same ground.
The circuit as you drew it is just not going to work. Transistors work with current flow, there is no where for the current to flow if you connect the emitter directly to the FET's gate because a FET has such a high input impedance.
Please ignore dhenry he is our resident idiot.