An electrothermal heater for an ice protection system includes a laminated heater mat which comprises a primary heater element layer, a secondary heater element layer, and at least one dielectric layer interposed between the primary and secondary heater element layers, and control apparatus which comprises power supply apparatus and a current detector. The control apparatus is configured to have (i) a first mode in which the power supply apparatus supplies a heater current to the primary heater element layer and does not supply a heater current to the secondary heater element layer and the current detector monitors the secondary heater element layer for detecting a leakage current of the heater current of the primary heater element layer indicative of burn-out of the primary heater element layer and (ii) a second mode in which the power supply apparatus supplies a heater current to the secondary heater element layer and does not supply a heater current to the primary heater element layer. The control apparatus is configured to switch from the first mode to the second mode in response to detection of said leakage current by the current detector.
ELECTROTHERMAL HEATER
2021-01-14
Patent
Electronic Resource
English