| 摘要 |
PURPOSE:To enhance heating efficiency while reducing the size by connecting a coil, having an intermediate point connected with one output terminal of a DC power supply, with a tank coil and a parallel resonance capacitor at the opposite ends thereof and connecting the tank coil in series with a heating coil disposed closely to a work. CONSTITUTION:When a FET 16 is turned ON by a drive circuit 4, a DC current flows from a DC power supply circuit 2 to a coil 22 to cause resonance of a resonance circuit comprising a capacitor 23, a tank coil 24, and a heating coil 33 and a current flows through the heating coil 33 in a predetermined direction. A current flowing through the tank coil 24 flows, as it is, through the heating coil 33. When the FET 16 is turned OFF and a FET 17 is turned ON at some moment of time a resonance current flows through the resonance circuit in reverse direction. Consequently, an inverter circuit 3 functions as a self-exciting oscillator to feed the heating coil 33 with a high frequency current depending on the turn ON/OFF of the FETs 16, 17. An eddy current is induced in a work W which is thereby induction heated. |
