I've been studying design for off-line switching converter chips to roll my own supply with the goal of making it smaller. If you do go that way, you can also do away with the optoisolated components, since the design wouldn't be isolated at that point. But the issue with that is that in order to operate the triac in quadrants 2 and 3 you want the positive supply rail for the LVDC side to be anchored on one of the AC legs and for "ground" to be 5 volts lower than that. With that configuration, driving the gate low would result in a negative voltage relative to the T1 leg of the triac, which gives us the operating quadrants we want. The alternative, driving the gate positive means quadrant 1 and 4, which is a problem because making a triac sensitive in quadrant 4 is hard (and can result in increased dV/dT sensitivity, which is bad).

Another issue with the design is that putting the load on the DC side requires having a 3 watt power supply. Putting the load on the AC side just means that the DC supply only needs to do the equivalent of lighting 3 LEDs, which is less than half a watt (the load of the controller is minuscule).

So for a sort of middle ground, I've made a board version that uses an open frame AC-DC supply that's fairly small and rated for 1 watt. The load is on the AC side and is switched by a second SSR (the first is the power supply holdfast). For 120VAC, 3 15 kΩ resistors will draw just under 1 watt each. This winds up being just a bit less than when the load is on the DC side (because of inefficiencies in the DC supply), but should still be visible enough to the Intelliflow.

As before, the system will bootstrap with a pushbutton across the first relay's switch terminals. That will start power long enough for the controller to start up and activate the first relay, holding the power on for the duration of the timing cycle. The second relay will switch the load on and off to simulate washing machine activity. When time is up, the first relay will be turned off. As the DC supply voltage falls, the brownout detector will hold the controller in RESET until the power is too low to matter.