+Dag Elias Sørdal
I can see what caps it has on the board. There is one solid state cap that looks to be maybe 47 uF? I like a bit more capacitance myself. Lacking any optical isolation on the control lines I cannot even imagine how the board works. They must employ a different scheme to keep noise from running up those paths. Those boards are built down to a cost so they are pretty minimal.
How did you fry your regulators? You can add reverse biased protection diodes to those. I always do. The 1N4004s in this schematic are protection diodes around a regulator. They make any surge to go back into the power supply and bypass the regulator itself http://i.imgur.com/K1tL4or.png
You can also see my optical isolation scheme in that schematic too. It is fiendishly clever if I do say so myself. There's a double inversion that leaves it positive logic. The Schmitt invertor squares the wave up out of the optocoupler too.