| 摘要 |
PURPOSE:To prevent power loss by a current detecting resistance at normal driving time by providing a bypass circuit in parallel with a current detecting resistor. CONSTITUTION:In a drive controller in which a current detecting resistor RE and a current controller 30 a re provided to enable to finely drive arbitrarily a stepping motor, a bypass circuit 40 is provided in parallel with a current detecting resistor R. A control signal CTRL is held at H level at normal drive time, a transistor Qa5 is turned ON to shorten a current detecting resistor RE, thereby preventing a current detecting resistor RE from producing power loss. Thus, when used for a seeking operation, its offset control is readily performed, and the loss of the speed during the normal seeking operation is prevented. |
