Circuits, systems and methods for integrating sensing and heating functions
Embodiments relate to integrated circuits, systems and methods for combined sensing and heating functions in structures suitable for use in deicing, heating and other applications. In an embodiment, an integrated circuit is coupled to a heating element and configured to control operation of the heating element to provide heat as well as to utilize the heating element as at least part of a sensing structure to sense the presence of ice, water or air on or near the heating element. In embodiments, the heating element comprises a conductive polymer structure, and the presence of ice, water or air is sensed based on a capacitance, impedance or other spectroscopy of the structure sensed and analyzed by integrated circuitry coupled to the structure.
1. A sensing and heating system comprising:
a first element and a second element that form a capacitor;
a switch configured to selectively connect the first and the second elements together; and
circuitry coupled to the first and second elements and configured to:
control the switch to disconnect the first element from the second element to receive a signal from at least one of the first or second elements related to a capacitance of the capacitor formed by the first and the second elements,
analyze the signal to detect a condition, and
control the switch to connect the first element to the second element together to activate the first and the second elements to provide heat if the signal is indicative of the condition.
2. The system of claim 1 , wherein the condition is one of water or icing.
3. The system of claim 1 , wherein at least one of the first and second elements is electrically conductive and comprises a conductive polymer.
4. The system of claim 1 , wherein the signal is spectrally analyzed to detect the condition.
5. The system of claim 1 , wherein the circuitry is configured to periodically sample at least one of the first and second elements to receive the signal.
6. The system of claim 1 , wherein the sensing and heating system is configured for at least one of a wind turbine application, a train or railroad application, an avionics application or an automotive application.
7. An integrated circuit comprising:
driving circuitry configured to control a heating and sensing structure, the heating and sensing structure including a first element and a second element that form a capacitor;
a switch configured to selectively connect the first and the second elements together; and
state machine circuitry coupled to the driving circuitry and configured to:
control the switch to disconnect the first element from the second element to receive a capacitance signal corresponding to a capacitance of the capacitor from the heating and sensing structure,
analyze the capacitance signal to determine a presence or absence of a condition proximate the heating and sensing structure, and
control the switch to connect the first element to the second element together and the driving circuitry based on the determined presence or absence of the condition.
8. The integrated circuit of claim 7 , wherein the condition is icing.
9. The integrated circuit of claim 7 , wherein the state machine circuitry is configured to control the driving circuitry by activating the driving circuitry if the presence of the condition is determined.
10. The integrated circuit of claim 7 , wherein the state machine circuitry is configured to analyze the capacitance signal to determine the presence or absence of the condition based on the capacitance of the capacitor.
11. The integrated circuit of claim 7 , further comprising temperature circuitry configured to determine a temperature of the heating and sensing element based on the capacitance signal received from the heating and sensing structure.
12. The integrated circuit of claim 7 , wherein the first element and the second element are configured to provide heat when connected together by the switch and the second element is configured to sense the condition based on the switch disconnecting the second element from the first element.
13. The integrated circuit of claim 12 , wherein the second element is configured to sensing the condition in cooperation with the first element.
14. The integrated circuit of claim 7 , wherein the integrated circuit is used in at least one of a wind turbine application, a train or railroad application, an avionics application or an automotive application.
15. A method comprising:
disconnecting first and second elements of a sensing and heating structure, the first and the second elements forming a capacitor;
sensing a capacitance between the first and the second elements of the sensing and heating structure having the first element disconnected from the second element;
analyzing the capacitance to determine whether moisture is present at the sensing and heating structure;
connecting the first element to the second element; and
activating the connected first and second elements of the sensing and heating structure to provide heat if a result of the analyzing is a presence of moisture.
16. The method of claim 15 , wherein sensing the capacitance comprises utilizing at least one of the first element and the second element of the sensing and heating structure.
17. The method of claim 15 , further comprising applying the sensing and heating structure to at least one of a wind turbine, a train, an aircraft, or an automobile.
18. The method of claim 15 , further comprising:
sensing at least one of an impedance or a resistance by the sensing and heating structure; and
analyzing the at least one of an impedance or a resistance to determine whether moisture is present at the sensing and heating structure.