To make heating electric power constant and to uniformly heat strip edges to desired temp. by controlling a C-type heating inductor voltage so as to become the heating power in accordance with thickness, line speed and kind of steel preset.
This control circuit A for making heating power constant is provided with a high-frequency power source 7, a matching board 6 provided between the C-type heating inductor 3c and the high-frequency power source 7, a heating power detecting part 8, a heating condition setting/calculating unit 10 by thickness, line speed and kind of steel and a control part 9 for making the power constant for calculating and controlling the voltage so that the heating power from the heating power detecting part 8 becomes the heating power which is set in the heating condition setting/ calculating unit 10. In this way, the heating power which is flactuated by the positional variation in the vertical direction of the strip and positional variation in the width direction is detected with the heating power detecting part 8 during heating and the voltage of the C-type heating inductor 3c is controlled so that the heating power becomes the heating power in accordance with the thickness, line speed and kind of steel which are preset.
NOHARA YOSHIKATSU
HATTORI HIDENORI
MIZUTA KEIJI
ASAHARA YUJI
MITSUBISHI HEAVY IND LTD
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