| 摘要 |
PURPOSE:To save unnecessary power of the unit at normal condition, by controlling the drive voltage of the switching elements for induction heating units, depending on the current flowing to the elements or the temperature of the elements. CONSTITUTION:In the unit with induction heating for pots on the heating work coil 10 by turning on and off the current in the semiconductor switching element GCS 6 depending on the rectangular signal of the oscillator 1, the pulse width modulation circuit 14 of rectangular signal, transformer 20 for current detection for GCS6, and temperature detector 22 are provided. Further, the width of the output pulse of the circuit 14 is changed depending on the current detection signal and temperature detection signal so that the drive voltage of GCS6 is controlled via the transistor 2, transformer 3 and rectifying circuits 15 and 17. Accordingly, if the current in the GCS6 is greater, the drive voltage is increased. Moreover, the unit 22 increases the output voltage even at lower or higher temperature by taking 25 deg.C as the boundary, then it turns on at lower temperature and off at higher temperature, to cover the characteristics of the GCS6. It is not required to supply a given drive voltage. |
