CONTROL DEVICE FOR ELECTROMAGNETIC INDUCTION HEATING, ELECTROMAGNETIC INDUCTION HEATING DEVICE, AND IMAGE FORMING DEVICE

摘要

PROBLEM TO BE SOLVED: To solve such an inconvenience that impedance of a negative side transistor of a driving circuit comprising a pair of same conduction type transistors becomes high at a negative polarity of output signals, and a reflow current can not be utilized to degrade the efficiency.;SOLUTION: A serial resonance circuit system more advantageous than a parallel resonance circuit system is adopted for designing the number of turns and the shape of an electromagnetic induction coil L11, and a main driving circuit 12 of the serial resonance circuit 11 is constituted with FETs Q11, Q12 connected in complementary symmetric connection. Respective gate electrodes of the FETs Q11, Q12 are driven by a pre-stage driving circuit 14, while maintaining the gate voltage of a positive side FET Q11 higher than the dead zone voltage of the main driving circuit 12 against the gate voltage of the negative side FET Q12, by connecting a constant-voltage circuit 13 generating a fixed voltage higher than a dead zone voltage of the main driving circuit 12, for example, a Zener diode between respective gate electrodes of the FETs Q11, Q12 of the main driving circuit 12.;COPYRIGHT: (C)2004,JPO&NCIPI