System and method for ovenized device temperature control
The present invention generally relates to a system and method for high accuracy temperature control of an oven used to operate an electronic device, sensor, or resonator at a fixed temperature. The fixed temperature operation may result in high stability and operation accuracy of the devices across varying environment temperature conditions. Specifically, the present invention relates to systems and methods that enable realizing, sensing, and controlling the temperature of an ovenized device with high temperature control, accuracy, relaxed temperature sense, and control electronics requirements.
1. A system for controlling the temperature of a device, the system comprising:
a voltage source;
a first path;
a second path connected in parallel with the first path;
a first resistor and a second resistor connected in series along the first path;
a third resistor and a fourth resistor connected in series along the second path;
a first branch connected to the first path between the first and second resistors;
a second branch connected to the second path between the third and fourth resistors;
an amplifier configured to amplify a voltage difference between the first branch and the second branch, wherein the voltage difference is set to zero at a specific temperature that is based on either the difference between a TCR of the first resistor and a TCR of the second resistor or the difference between a TCR of the third resistor and a TCR of the fourth resistor; and
a controller configured to control a heater by changing the heater electrical signal such that the voltage difference is approximately zero based on an output of the amplifier.
2. The system of claim 1 , wherein the first resistor is identical to the fourth resistor and the second resistor is identical to the third resistor.
3. The system of claim 1 , wherein the voltage difference between the first branch and the second branch varies with temperature.
4. The system of claim 1 , wherein a target temperature is set to be the temperature at which the voltage difference between the first branch and the second branch is zero.
5. The system of claim 1 , wherein the temperature at which the voltage difference between the first branch and the second branch is zero depends on the difference between the TCR of the first resistor and the TCR of the second resistor.
6. The system of claim 1 , wherein the temperature at which the voltage difference between the first branch and the second branch is zero depends on the difference between the TCR of the third resistor and the TCR of the fourth resistor.
7. The system of claim 1 , wherein the first resistor and the second resistor are constructed with different materials.
8. The system of claim 1 , wherein each of the first resistor, second resistor, third resistor, and fourth resistor, has a different resistance value and wherein both the first resistor and the third resistor have a first TCR and both the second resistor and the fourth resistor have a second TCR such that the first TCR is different from the second TCR.
9. A system for controlling the temperature of a device, the system comprising:
a voltage source;
a first path;
a second path connected in parallel with the first path;
a third path;
a first resistor and a second resistor connected in series along the first path;
a third resistor and a fourth resistor connected in series along the second path;
a first branch connected to the first path between the first and second resistors;
a second branch connected to the second path between the third and fourth resistors; and
an amplifier, a controller, and a temperature control device connected along the third path;
wherein the amplifier is configured to amplify a voltage difference between the first branch and the second branch;
wherein the voltage difference is set to zero at a specific temperature that depends on the difference between a TCR of at least two of the first, second, third, or fourth resistors; and
wherein the controller is configured to control the temperature control device by changing the device electrical signal such that the voltage difference is approximately zero based on an output of the amplifier.
10. The system of claim 9 wherein a target temperature is set to be the temperature at which the voltage difference between the first branch and the second branch is zero.
11. The system of claim 9 , wherein the temperature at which the voltage difference between the first branch and the second branch is zero depends on the difference between the TCR of the first resistor and the TCR of the second resistor.
12. The system of claim 9 , wherein the temperature at which the voltage difference between the first branch and the second branch is zero depends on the difference between the TCR of the third resistor and the TCR of the fourth resistor.
13. The system of claim 9 , wherein the first resistor and the second resistor are constructed with different materials.
14. The system of claim 9 , wherein each of the first resistor, second resistor, third resistor, and fourth resistor, has a different resistance value and wherein both the first resistor and the third resistor have a first TCR and both the second resistor and the fourth resistor have a second TCR such that the first TCR is different from the second TCR.
15. The system of claim 9 , wherein the temperature control device is selected from the group consisting of a heater and a cooler.
16. A method of controlling a temperature of a device, the method comprising:
heating the device;
sensing the temperature;
calculating a voltage difference between a voltage of a first branch, which is connected to a first resistor and a second resistor, and a voltage of a second branch, which is connected to a third resistor and a fourth resistor;
amplifying the voltage difference; and
controlling a heater, based on the amplified voltage difference, to attain a voltage difference of zero; and
setting the voltage difference to zero at a specific temperature based on either the difference between a TCR of the first resistor and a TCR of the second resistor or the difference between a TCR of the third resistor and a TCR of the fourth resistor.
17. The method of claim 15 , wherein the voltage along the first branch and the voltage along the second branch depend on the temperature of the device.