| 摘要 |
PROBLEM TO BE SOLVED: To prevent damage of a switching circuit due to a high voltage, and quicken a rise of an excitation current by effectively utilizing a counter electromotive voltage of the exciting coil.SOLUTION: A convert circuit 11 converts, on the basis of excitation signals SA, SB, an input current flowing from a current input terminal Tin to a current output terminal Tout into an excitation current Iex via a D1 and a D2, and supplies the excitation current Iex to an exciting coil L. A charge/discharge circuit 13 charges, by a DB, a capacitative element C owing to a counter electromotive voltage applied from the exciting coil L, and supplies, by an SW11 and an SW 12 for a high voltage, a discharge current from the capacitative element C to an exciting coil L in response to the polarity of the excitation current Iex. |
