An apparatus comprising a switch, a fuse, and a sensor that is capable of
detecting the presence of flammable vapors and responsively changing in
resistance, wherein the sensor enables the switch to supply current to
the fuse which opens to shut down an appliance burner. The fuse is
connected in series with a control circuit that enables a gas valve to
supply gas to the burner 65. The apparatus comprises a voltage divider
circuit that includes the sensor, which upon exposure to flammable
vapors, increases in resistance to provide a voltage input to the gate of
a FET 100. The FET switches on and conducts a current that blows the fuse
to interrupt the appliance burner control circuit and shut down burner
operation.