Apparatus to control device temperature utilizing multiple thermal paths

1. An apparatus to control a temperature of a device, which apparatus comprises:

a thermal head fluid path adapted to be in thermal contact with the device, the thermal head fluid path being disposed to receive thermal transfer fluid from a combined path and to output thermal transfer fluid fluidly to a pump assembly;

a temperature sensor in communication with a controller and being operable to sense a temperature in response to the thermal head fluid path;

the pump assembly being disposed to output the thermal transfer fluid fluidly to each of a first path, a second path, and a third path;

the first path being fluidly connected at a first end to the output of the pump assembly and at a second end to the combined path, the first path being in thermal contact with a heating assembly;

the second path being fluidly connected at a first end to the output of the pump assembly and at a second end to the combined path, the second path being in thermal contact with a cooling assembly;

a third path being fluidly connected at a first end to the output of the pump assembly and at a second end to the combined path; and

a first valve in the first path, a second valve in the second path, and a third valve in the third path; wherein:

the first, second, and third valves are operable, in response to the controller, to control thermal transfer fluid flow through the first, second, and third paths.

2. The apparatus of claim 1 further comprising:

a thermal head having the thermal head fluid path disposed therethrough.

3. The apparatus of claim 2 wherein the temperature is a temperature of the thermal head.

4. The apparatus of claim 3 further comprising:

a first path temperature sensor in communication with the controller and being operable to sense a temperature in response to the first path; and

a second path temperature sensor in communication with the controller and being operable to sense a temperature in response to the second path;

wherein:

the heating assembly is operable, in response to the controller; and

the cooling assembly is operable, in response to the controller.

5. The apparatus of claim 1 wherein one or more of the first, second and third valves is a pulse-width modulated valve.

6. The apparatus of claim 1 which further comprises a counter-flow heat exchanger disposed so that, in operation, thermal transfer fluid from the thermal head fluid path flows through a primary side of the counter-flow heat exchanger and thermal transfer fluid in the third path flows through a secondary side of the counter-flow heat exchanger.

7. The apparatus of claim 1 which further comprises a counter-flow heat exchanger disposed so that, in operation, thermal transfer fluid from the thermal head fluid path flows through a primary side of the counter-flow heat exchanger and thermal transfer fluid output from the pump assembly flows through a secondary side of the counter-flow heat exchanger.

8. The apparatus of claim 1 further comprises a counter-flow heat exchanger disposed so that, in operation, thermal transfer fluid from the thermal head fluid path flows through a primary side of the counter-flow heat exchanger to the pump assembly and thermal transfer fluid flowing between a confluence of the first, second and third paths and the thermal head fluid path flows through a secondary side of the counter-flow heat exchanger.

9. The apparatus of claim 1 which further comprises:

a heat exchanger in thermal contact with thermal transfer fluid flowing between a confluence of the first, second and third paths and the thermal head fluid path; and

a heating assembly in thermal contact with the heat exchanger, the heating assembly being operable in response to the controller.

10. The apparatus of claim 1 wherein the heating element is a resistive heater.

11. The apparatus of claim 1 wherein the pump assembly comprises a pump.

12. The apparatus of claim 1 further comprising thermal transfer fluid, the thermal transfer fluid being a gas or a liquid.

13. An apparatus to control a temperature of a device, which apparatus comprises:

a thermal head fluid path adapted to be thermally contacted to the device;

a temperature sensor in communication with a controller and being operable to sense a temperature in response to the thermal head fluid path;

a first path fluidly connected at a first end to a first output of a valve assembly and at a second end to the thermal head fluid path, the first path being in thermal contact with a heating assembly;

a second path fluidly connected at a first end to a second output of the valve assembly and at a second end to the thermal head fluid path, the second path being in thermal contact with a cooling assembly;

a third path fluidly connected at a first end to a third output of the valve assembly and at a second end to the thermal head fluid path;

a pump assembly disposed to receive thermal transfer fluid from the thermal head fluid path and to output the thermal transfer fluid to the valve assembly; and

the valve assembly being operable, in response to the controller, to control thermal transfer fluid flow from the first, second, and third outputs;

wherein the valve assembly comprises:

a first valve operable in response to the controller to control the flow of thermal transfer fluid to the first path;

a second valve operable in response to the controller to control the flow of thermal transfer fluid to the second path; and

a third valve operable in response to the controller to control the flow of thermal transfer fluid to the third path.