Triaxial temperature limited heater

Abstract

Certain embodiments provide a heater. The heater includes an inner electrical conductor. A heater section at least partially surrounds the inner electrical conductor. The heater section is configured to generate an electrically resistive heat output during application of time-varying electrical current to the heater section. The heater section includes ferromagnetic material. An outer electrical conductor at least partially surrounds the heater section. An applied time-varying electrical current is configured to propagate through the inner electrical conductor and the outer electrical conductor in substantially the same direction. The applied time-varying electrical current is configured to propagate through the heater section in a substantially opposite direction. The heater provides a first heat output when time-varying electrical current is applied to the heater below a selected temperature, and a second heat output approximately at and above the selected temperature during use. The second heat output is reduced compared to the first heat output.

Dependencies are inferred from the claim text.