| 摘要 |
In the present invention, a switching circuit (11) switches the driving current flowing from a current input terminal (Tin) to a current output terminal (Tout) to excitation current (Iex) to an excitation coil (L) via a diode (D1, D2) on the basis of an excitation signal (SA, SB), supplying the result, and a charging/discharging circuit (13) charges a capacitive element (C) with counter electromotive voltage from the excitation coil (L) by means of a diode bridge (DB), and supplies discharge current from the capacitive element (C) to the excitation coil (L) matching the polarity of the excitation current (Iex) by means of a high voltage-resistance-specification switch (SW11, SW12). As a result, it is possible to increase the speed of startup of excitation current by taking advantage of the counter electromotive voltage of the excitation coil while avoiding damage to the switching circuit resulting from high voltage. |
