Thanks,
Dave - Now that looks like a great way to enjoy your last Sunday afternoon
Yea, I saw the post but I wasn’t sure exactly how it would relate to the hot tub control. Now I see that Henrik's illustration makes it clear, great illustration by the way. Hot tub would be much simpler due to the long time frame to move temperature. After reviewing the post I think a standard 1k pulse stream driven by PID on-off time would do the trick. I shouldn’t have to worry about zero-crossing, phase angles, half cycles, or any of that stuff taken into consideration when speed is a concern. Does that sound logical?

Wayne