Don Klipstein wrote:

I have heard of CFLs with design that hasthe electronics blow when the
bulb part has aged into "a state of failure" (my words). I do think that
manufacturers of those would do well to add a fuse that blows as a result
of electronics failure, and blows to keep the electronics (fuse-acting
subset thereof) from having to serve as a fuse with smoke output.
- Don Klipstein )

Hi Don,

Self destruct was one of the recommendations for the fed CFL
design contest since attempting to start a bad bulb caused
the most risk for a fire from component failure. One of the
component manufacturers had a novel circuit that shut down
when the inverter went high frequency when a bad bulb no
longer provided a proper load.

The last few cfls we've opened up have either a micro fuse
or a 5mm fuse in a piece of heat shrink that serves as a
"jumper" between the pc board and the center lead of the
lamp base. Some earlier cfls had a 0.1" piece of ~#30
magnet wire stuck between two pads on the pc board or a 22
ohm 1/4 watt resistor in series with the input. I guess
it's easier to UL qualify a UL recognized fuse ;-)

-- larry / dallas