FYI Light bulb burning out and shorting
triac.
An enormous number of years ago, I remember
reading that burn-out of Phillips brand
lightbulbs shorted the triacs far less often
than other brands. The speculated
explaination was: Phillips did not stretch
their filiment, in manufacture, as taut as
other brands . The bulb is less likely to
burn out at turn-on (turn-out burn-out
usually happens when the switch makes
contact, or the triac fires, when the AC
sine is at peak - creating larger inductive
kick when the filiment breaks which is
greater than the mediocure 400v PIV triacs).
I don't know if true or not, but I do know I
have had Phillips bulbs burn out and the
lamp module(s) survived.
FWIW
