| 摘要 |
In order to reliably maintain the desired execution voltage in control of pre-heating and realize highly reliable control of pre-heating, the repetition cycle (Tpre) of a pulse voltage in a pre-heating period is set by a calculation control unit (52) so as to be large relative to the repetition cycle (Tnr) during a normal electrification time after the end of the pre-heating period, and although the root-mean-square value of the voltage applied to an internal heater (1a) can be maintained at the desired value, during the normal electrification time after the end of the pre-heating period, the repetition cycle (Tnr) of the pulse voltage is set so as to be relatively short, as conventionally. |
