| 摘要 |
PURPOSE:To keep heating efficiency constant by providing a correcting circuit increasing or decreasing the preset value of the input current to a heating command circuit and inverters, and invariably feeding constant input power regardless of the number of the inverters. CONSTITUTION:A correcting circuit 13 is operated to adjust preset values of voltage values generated across both ends of resistors 7-11 inserted in series with inverters 6-8, i.e., preset values of input current values of the inverters 6-8 according to the number of the inverters 6-8 actually performing the heating action, thus constant input power can be invariably fed to the inverters 6-8 regardless of the number of the actually heating inverters 6-8. When the preset values of the input current of the inverters 6-8 are adjusted by the DC power output, the input power of the inverters 6-8 can be kept nearly constant. |
