| 摘要 |
PURPOSE:To increase the lifetime of a driving device by reversely rotating a motor for a predetermined time length when the motor is overloaded and stopping the motor. CONSTITUTION:When a switch 6 is closed, transistors Tr1, Tr6, Tr2 are conducted, a transistor Tr7 is simultaneously conducted, a transistor Tr8 is turned OFF, and similarly transistors Tr3, Tr4 are turned OFF. Thus, a motor 5 is rotated forwardly. This state is maintained by the transistor Tr5 of an overload detector circuit. When an overload is applied to the motor 5, the induced voltage of the motor 5 is decreased to turn the transistor Tr5 off, the motor 5 is thus energized reversely while a capacitor C1 is discharged by the operations of the transistors Tr6, Tr7, Tr8, and the motor is stopped. |
