초록 ▼

A method of determining the temperature, preferably the ice boundary temperature, of an electrical resistive heating element of a de-icing system for airplanes, helicopters, and the like, preferably for a fully automatic control of the heating times of the heating elements. Additional temperature se

A method of determining the temperature, preferably the ice boundary temperature, of an electrical resistive heating element of a de-icing system for airplanes, helicopters, and the like, preferably for a fully automatic control of the heating times of the heating elements. Additional temperature sensors are avoided and circuitry costs are substantially reduced by using the resistive heating elements themselves for determining the temperature. The resistance variation due to temperature variations of an element is ascertained by a current-voltage measurement, and a temperature variation of the element is determined from the resistance variation while using the temperature coefficient. The current-voltage measurement may be based on Ohm\s law with a following analog or digital processing of the signal.

대표청구항 ▼

An apparatus for determining the temperature of a resistive heating element having a temperature coefficient, comprising: at least one resistive heating element; a power supply connectable to said heating element for supplying a powering voltage and powering current to said heating element; a contr

An apparatus for determining the temperature of a resistive heating element having a temperature coefficient, comprising: at least one resistive heating element; a power supply connectable to said heating element for supplying a powering voltage and powering current to said heating element; a controllable power switch connected between said power supply and said heating element for interrupting voltage and current supplied to said heating element; a voltage sensor connected to said heating element for generating a voltage signal which is proportional to an instantaneous voltage supplied by said power supply to said heating element; a current sensor connected to said heating element for generating a current signal which is proportional to instantaneous current supplied to said heating element by said power supply; a comparator connected to said voltage and current sensors for comparing said voltage and current signals and for generating a difference signal corresponding to a difference between said voltage signal and said current signal; and logic means including a predetermined switch threshold, said switching threshold corresponding to a desired temperature of said heating element, said difference signal corresponding to said switching threshold when said heating element reaches the desired temperature.