System and method to measure temperature and generate heat using a resistive material
AssigneeVarian Medical Systems, Inc.
InventorKenneth Wayne Zapalac
Life of this patent
Estimating the term…
Abstract
A heating system includes a power supply that applies a first voltage to a sense resistor in series with a resistive heating material during a first time period; and a controller that determines a temperature of the resistive heating material based on a current through the sense resistor and a second voltage across the resistive heating material during the first time period. Additionally, the controller commands the power supply to provide a third voltage to the resistive heating material during a second time period, and the third voltage is based on the temperature of the resistive heating material.
Claims19
A heating system, comprising:
- a power supply that applies a first voltage across a sense resistor in series with a resistive heating material during a first time period;
- a controller that determines a temperature of the resistive heating material based on a current through the sense resistor and a second voltage across the resistive heating material during the first time period;
- a first switch between the power supply and the sense resistor;
- and
- a second switch between the power supply and the resistive heating material, wherein the first switch is closed during the first time period, and during a second time period, the first switch is opened and the second switch is closed.
A method of heating, comprising:
- applying a sense voltage to a sense resistor in series with a resistive heater during a first time period;
- determining a current through the sense resistor during the first time period;
- determining a voltage across the resistive heater during the first time period;
- calculating a resistance of the resistive heater based on the current and the voltage during the first time period;
- determining a temperature of the resistive heater based on the resistance of the resistive heater;
- closing a first switch between a power supply and the sense resistor during the first time period;
- and
- opening the first switch and closing a second switch between the power supply and the resistive heater during a second time period.
A system to perform heating, comprising:
- a sensing circuit;
- a heating circuit;
- a controller circuit;
- a first switch between a power supply and a sense resistor of the sensing circuit;
- and
- a second switch between the power supply and a resistive heating material of a heater of the heating circuit,
- wherein the controller circuit controls power to the sensing circuit to determine a resistance value of the heater that is in both the sensing circuit and the heating circuit, the first switch is closed during a first time period, and during a second time period the first switch is opened and the second switch is closed.
Dependencies are inferred from the claim text.