Apparatus and method for adjusting a curie effect temperature sensing system

In an apparatus for controlling the temperature of a cold plate including means for cooling the cold plate, the improvement comprising:

• a curie effect temperature sensing switch having first and second operating temperatures, a temperature differential, a closed condition, and an open condition, the temperature switch thermally contacting the cold plate and operatively connected to the cooling means;
• the temperature switch activating the cooling means when the temperature of the cold plate is above the first operating temperature and deactivating the cooling means when the temperature of the cold plate is below the second operating temperature;
• means for producing a magnetic field of variable strength extrinsic of and relative to the temperature switch such that the operating temperatures and the temperature differential can be controlled by the magnetic field produced by the magnetic field means;
• first means for incrementally varying the strength of the magnetic field produced by the magnetic field means to adjust the operating temperatures;
• and
• second means for incrementally varying the strength of the magnetic field produced by the magnetic field means as a function of whether the temperature switch is in its open or closed condition to adjust the temperature differential.

In an apparatus for controlling the temperature of reagents or other substances including a cold plate on which the reagents or other substances rest and electrically controlled means for cooling the cold plate, the improvement comprising:

• a curie effect temperature sensing switch having first and second operating temperatures, a temperature differential, an open condition and a closed condition, the temperature switch thermally contacting the cold plate and electrically connected to the cooling means;
• the temperature switch activating the cooling means when the temperature of the cold plate is above the first operating temperature and deactivating the cooling means when the temperature of the cold plate is below the second operating temperature;
• means for producing a magnetic field of variable strength, the magnetic field means fixed external of and relative to the temperature switch such that the operating temperatures and the temperature differential are decreased by the magnetic field produced by the magnetic field means;
• first means for incrementally increasing the strength of the magnetic field produced by the magnetic field means to decrease the operating temperatures;
• and
• second means for incrementally increasing the strength of the magnetic field produced by the magnetic field means as a function of whether the temperature switch in its open or closed condition to decrease the temperature differential.

A method for adjusting the operating temperatures and the temperature differential of a curie effect temperature sensing switch having an on condition and an off condition comprising:

• producing a magnetic field of variable strength extrinsic of and relative to the temperature switch such that the operating temperatures and the temperature differential of the temperature switch can be controlled by the extrinsic magnetic field;
• incrementally varying the strength of the extrinsic magnetic field to adjust the operating temperatures of the temperature switch;
• and
• incrementally varying the strength of the extrinsic magnetic field as a function of the temperature switch condition to adjust the temperature differential of the temperature switch.

A method for controlling the temperature of a cold plate having a cooling element operatively connected to a curie effect temperature sensing switch, the temperature switch also being in thermal contact with the cold plate and having first and second operating temperatures and a temperature differential, comprising:

• activating the cooling element when the temperature of the cold plate is above the first operating temperature;
• deactivating the cooling element when the temperature of the cold plate is below the second operating temperature;
• using an electromagnet to produce a magnetic field of variable strength external of and relative to the temperature switch such that the operating temperatures and the temperature differential can be controlled by the external magnetic field;
• incrementally varying the current flowing to the electromagnet to adjust the operating temperatures;
• and
• incrementally changing the current flowing to the electromagnet to alter the strength of the external magnetic field as a function of whether the temperature switch is activating or deactivating the cooling element to adjust the temperature differential.