Heater control device, and control method and control program for heater control device

摘要

A heater control device includes a current calculating unit (20) which calculates a third value of current based on a first value of current flowing through a first PTC element of a first PTC heater which is in an energized state and a second value of current estimated to flow through a second PTC element of a second PTC heater which is to be newly put into an energized state next, and a switching control unit (21) which maintains a non-energized state of the second PTC element of the second PTC heater until it is determined that the third value of current calculated by the current calculating unit (20) is less than a predetermined maximum allowable value of current and puts the second PTC element of the second PTC heater into an energized state when the third value of current is less than the predetermined maximum allowable value of current.

主权项

1. A heater control device to be applied to a heater unit provided with a plurality of PTC heaters each of which comprises a PTC element which is a resistive element in which a current flowing therethrough reaches its peak value as its resistance value falls once when energized and then its resistance increases, the heater control device comprising:
a switching control unit which sequentially energizes the PTC element which is included in each of the plurality of PTC heaters, one after another; a current detecting unit provided on a current path to the heater unit and which detects a first value of current flowing through a first PTC element of a first PTC heater among the plurality of PTC heaters, the first PTC heater being presently in an energized state; and a current calculating unit which acquires the first value of current which is detected by the current detecting unit, wherein the current calculating unit calculates a third value of current that is the sum of the first value of current which is acquired and a second value of current estimated as a maximum value to flow through a second PTC element of a second PTC heater which is to be put into an energized state next to the first PCT heater; and the switching control unit which maintains a non-energized state of the second PTC element of the second PTC heater until it is determined that the third value of current calculated by the current calculating unit is less than a predetermined maximum allowable value of current which is stored in advance, and puts the second PTC element of the second PTC heater into an energized state when the third value of current is less than the predetermined maximum allowable value of current.