Patent ID: 8049373

Claim:
An apparatus for stabilizing a power supply of a heater housing box cooling apparatus for cooling a heater housing box comprising: a power transformer for transforming an output voltage of an alternating-current power supply supplied from the heater housing box, a plurality of taps provided in a winding of the power transformer for controlling the transformed output voltage within an allowable voltage range, a tap changeover part for changing over the plurality of taps, an electronic controller including an output voltage detector for detecting the transformed output voltage, and a delay part for limiting a rise of the transformed output voltage when turning on the alternating-current power supply, wherein the electronic controller delays control of the tap changeover part until the transformed output voltage rises to an initial value responsive to the delay part limiting the rise of the transformed output voltage, the initial value being less than the allowable voltage range, and wherein a first resistor as the delay part is provided at a secondary side of the power transformer, and a switch element for lowering a resistance value of the first resistor in an ordinary operation after a delay action is connected in parallel with the first resistor.