A schematic has been made:
This design originates from some time in the 1980's.
New technology using MOS designs has been made available, as SSR's - I'll be looking into these new designs. One major advantage to SSR MOS designs are that you no longer loose 1.2W per Amp over a Triac. The triac design has the advantage of being relatively low-cost to implement.
Anyone has some SSR recommendations?