Patent ID: 8423197

Claim:
A heater energization control apparatus for controlling energization of a heater having a heating resistor which generates heat upon supply of electricity thereto, wherein the heater constitutes a heat generation section of a glow plug mounted to an internal combustion engine, the apparatus comprising: first resistance acquisition means, operable when the internal combustion engine to which the heater is mounted remains stopped, for supplying electricity to the heating resistor every time a predetermined wait time elapses and for acquiring, as a first resistance, an electricity supply resistance at that time; and determination means for determining that the glow plug has been exchanged for another same type of glow plug, when the first resistance is greater than a predetermined first reference value, wherein the heating resistor is a heating resistor whose resistance changes with a temperature change thereof in accordance with a positive correlation between the temperature and the resistance; the heater energization control apparatus is configured to control the supply of electricity to the heating resistor in accordance with a resistance control scheme in which the supply of electricity to the heating resistor is controlled such that the resistance of the heating resistor coincides with a target resistance; and the heater energization control apparatus comprises: second resistance acquisition means, operable in response to (i) the determination means determining that the glow plug has been exchanged for another same type of glow plug, (ii) the internal combustion engine being operated for a first time after it is determined that the glow plug has been exchanged for another same type of glow plug, and (iii) the internal combustion engine being stopped after being operated the first time once it has been determined that the glow plug has been exchanged for another same type of glow plug, for supplying electricity to the heating resistor, and for acquiring, as a second resistance, the electricity supply resistance at that time; first information acquisition means, operable when the second resistance is acquired, for acquiring information regarding a temperature of an environment in which the heater is used; first computation means for computing the target resistance on the basis of the second resistance and the information regarding the environmental temperature; and energization control means, operable when the internal combustion engine is operated, for controlling the supply of electricity to the heating resistor such that the electricity supply resistance at the time when electricity is supplied to the heating resistor coincides with the target resistance.