| 摘要 |
PURPOSE:To facilitate the absorption of kick back voltage generated at the time of currents in driving coils being switched, by setting the gains of amplifiers so that the outputs of the amplifiers is be kept in a range of good linearity of the amplifiers. CONSTITUTION:The outputs of Hall elements 1, 2, 3 corresponding to 3-phase driving coils are amplified with Hall amplifiers 4, 5, 6, put into a matrix circuit 7, and changed into switching signals based on a control signal S corresponding to a rotational speed command. Then the signals are put into a control section 8. The control section 8 generates a current flow switching signal fro each driving coil on the basis of these switching signals, and feed them to the driving coils through driving amplifiers 9, 10, 11. The gains of the Hall amplifiers 4, 5, 6 and driving amplifiers 9, 10, 11 are set small so that each output is kept in a range of good linearity. |
