| 摘要 |
PURPOSE:To prevent an inverter from being broken when the heating output is decreased by providing a power source selecting means which selects one of multiple power sources with different voltage values in response to the preset heating output level and applies it to the inverter. CONSTITUTION:One of multiple power sources with different voltage values is selected by a power source selecting means 35 in response to the heating output level set by an output adjusting means 19 and applied to an inverter 14. If a power source with a low voltage value is selected and applied to the inverter 14 when the preset heating output level is small, an excessive current does not flow through a switching element constituting the inverter 14, thus the inverter 14 is prevented from being broken. |
