Here's what I thought was a pretty simple project. Up-counter fires off a series of opto-triacs sequentially which in turn fire power triacs for the AC load. Its use is for theatrical lighting. My power triacs are BTA20-700BW, and the 8 triac resistors (R4-R11) are 5.1k 2W. I'm thinking that these values might be off, I wasn't at all sure how to calculate them. I'm very new to using triacs.
The problem I'm having is that all 4 AC load lines are always ON. Can anyone see why this might be? I'm wondering if I need higher values for the gate resistors? Also, which the power triac gate connected as it currently is, I'm thinking the floating voltage is turning the triac on even when the opto-triacs aren't conducting. If I move the gate connection to the other pin of the opto-triacs, will that solve my problem?
Any suggestions/criticism are definitely appreciated.
View attachment ControlBox.bmp
View attachment ControlBox.sch
The problem I'm having is that all 4 AC load lines are always ON. Can anyone see why this might be? I'm wondering if I need higher values for the gate resistors? Also, which the power triac gate connected as it currently is, I'm thinking the floating voltage is turning the triac on even when the opto-triacs aren't conducting. If I move the gate connection to the other pin of the opto-triacs, will that solve my problem?
Any suggestions/criticism are definitely appreciated.
View attachment ControlBox.bmp
View attachment ControlBox.sch