Controller to control electrical power of load in constant
AssigneeSumitomo Electric Industries, Ltd.
InventorTomoko IKAGAWA
Life of this patent
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Abstract
A heater controller for controlling a heater precisely in the equi-power mode is disclosed. The controller includes a current source, a voltage monitor to detect a voltage drop caused in the heater, and a controller. The voltage drop may be converted to the digital form as refereeing to the first reference, while, the heater current is converted from the digital form as referring to the second reference. The second reference shows substantial temperature dependence, while, the first reference has lesser temperature dependence. The control corrects the temperature dependence of the second reference as referring to the first reference.
Claims9
A load controller, comprising:
- a current source to supply a current to a load;
- an analog-to-digital converter coupled with a first reference;
- a digital-to-analog converter coupled with a second reference that has temperature dependence greater than temperature dependence of said first reference;
- and
- a controller configured to control said current source through said digital-to-analog converter by receiving an output of said analog-to-digital converter,
- wherein said controller receives said second reference through said analog-to-digital converter and corrects temperature dependence of said second reference.
A method to control electrical power supplied to a load in constant to target power by a feedback loop including an analog-to-digital converter, a controller, a digital-to-analog converter, and a current source, said method comprising steps of:
- detecting a voltage drop caused in said load by a current flowing therein through said analog-to-digital converter as referring to a first reference;
- detecting a second reference through said analog-to-digital converter, said second reference being referred by said digital-to-analog converter that controls said current source and having temperature dependence greater than temperature dependence of said first reference;
- calculating another current next supplied to said load through said digital-to-analog converter and said current source by said controller as correcting said temperature dependence of said second reference;
- and
- providing said calculated current to said load.
Dependencies are inferred from the claim text.