I changed the circuit so Vcc is not a 5 volt offset from mains anymore (just had to remove one jumper). I also removed diodes and resistors that tapped off the high side of the transformer. I added an Arduino and a couple opto-couplers. The Arduino works fine, but unfortunately, when the opto-coupler turns on, the triac does not turn on. Attached is my revised circuit.
In the original circuit, if I applied -5v to the triac (actually to the 91 ohm resistor in front of the triac), it would turn on. But with the revisions I made that doesn't work anymore. I even bypassed the opto-coupler and put the -5v on the 91 ohm resistor, but that didn't work either.
Any suggestions as to what's wrong?