| 摘要 |
PURPOSE:To eliminate the unstable operation and the output loss of a motor even when an exciting current is stepwisely varied like in I-II phase excitations by altering a reference signal in response to the I-II phase excitations. CONSTITUTION:The value of a reference signal VREF is set to multiple more than two stages by a controller 10 such as a CPU and a plurality of resistor setters R1, R2,... The timing of switching in multistages of the reference signal VREF is set in response to the transient characteristic at phase converting time of the drive current (i). Thus, the current flowed to a detecting resistor R can be indispensably stepwisely varied like I-II phase excitations, and stably constant-current drive can be performed. |
