| 摘要 |
PURPOSE:To efficiently drive motors by detecting the fact that the drive current becomes the prescribed upper or lower limit value, and intermittently controlling the drive current of the motors by the logical product of the detected output and the motor drive pulse. CONSTITUTION:Since the other input 20 of a logic product circuit 30 is initially ''1'' when a signal is generated from a control circuit 29, a motor 21 rotates with a switching element 24 conducted. When the current reaches the upper limit value, the voltage produced at a resistor 25 is detected by a Schmitt trigger 28, the signal 20 is inputted to a logic product circuit 30 to set a switching element 24 to OFF and a switching element 27 to ON, thereby discharging the energy of the motor 21 through a diode 26. Then, the lower limit value is detected by a trigger circuit 28 to be returned to the operating state, and repeated. Accordingly, the excess current can be prevented at the starting time, and the motor can be extremely efficiently operated. |
