triac driver circuits
You can drive the triac directly from a port of any 8051. The chasis will be live as you'll have to connect the gound of the power supply to the neutral and the phase will be switched by the Triac. Unless the triac develops a "short" for some reason, from the gate to MT1 or MT2, no risks are seen by me in person. Only thing to remember is that the circuit will be live and one should be very cautious handling it. I am using similar circuit to run 6.2 volts 40 nos bulbs on AC220 volts since years. I use 89C52, a ULN2003, a LED, a resistor and then the Triac in sieres.
When you swittch a load through the Triac, a noise will be generated due to the switching and this will be superimposed on the AC lines. The snubber circuit minimises such interference created and keep the ac lines free of noises. But one has to calculate exact values of components to supress the noise and harmonics. Snubber will generally consist of a capacitor and resistor in sieres across the swittching terminals of the triac and again a VDR/ Mov across the same.
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