| 摘要 |
<P>PROBLEM TO BE SOLVED: To appropriately control a heating means (infrared heater) before becoming unusable due to the disconnection etc. <P>SOLUTION: A voltage to be outputted from a DC power generation circuit 20 to the heating means 14 is controlled at a prescribed target value (heater rated-voltage) by a control means 17, and the reduction ratio (a ratio to an initial value) of the current flowing in the heating means and detected by a current detecting means 10 at the time of controlling is calculated, and then, by comparing the obtained value with the current reduction ratio of the using limit (prediction based on the known reduction ratio at the disconnection time), whether the heating means reaches the usable limit is decided, then, information on the usable limit is given before the occurrence of the disconnection. The decision of the use propriety is performed every fixed period, and data on the decision is accumulated as history data. Error checking is applied on the current reduction ratio based on the history data, and also, by referring to the history data, it is confirmed whether or not the failure is an early accident such as a sudden disconnection, and then, the heating means is appropriately controlled. <P>COPYRIGHT: (C)2004,JPO |
