Thanks again, Boncuk. I've thought about that approach and didn't pursue it because I didn't know how to make the dummy load. You may be right that flipping the inverters on and off could create a power spike and damage the el-wire. I would really like to understand how to build your circuit, but I can't interpret the diagram. I can tell what the battery, resisters and diode are, but I really can't tell what is what. Perhaps "K" is the relay, but which side is NO or NC? I have no idea what Q1, J2, J3, D2, or S1 are. I'm used to diagrams using symbols like this:
https://www.arrl.org/tis/info/pdf/8402019.pdf. Do you have a link to an article that would decode the symbols used in your diagram?
That said, need a different solution for the near term. I have already built my circuit, and I need to use it at an event coming up in a few weeks. I have it working pretty well, but I just want to see if there is a way to prevent a short in one strand of el-wire (whether caused by a spike from the inveter or some other cause) from burning out another. I'm pretty sure this has happened because of the order that the el-wire strands burned out.
For example, if inverters 1-5 go on and off in sequence, and the el-wire connected to inverter 3 burns out for example, there is a good chance that after a couple of more passes of the sequence, the el-wire connected to inverter 4 will burn out. I think due to the physical nature of the inverters, the fact that the relay 3 turns off at the exact instant that relay 4 turns on, and the fact that all of the el-wire strands share one common wire (that is, one side of the inverters are connected together) there may be a brief time when el-wire 3 is connected to el-wire 4.
So, for example, is there a simple circuit I could put between the relay and the inverter that would delay power going to the inverter for a fraction of a second after the relay closes? Or, is there something I could put between the inverter and the e-wire to prevent AC power from flowing from one inverter to another for the fraction of a second they are both powered?
Thanks again for any help.