| 摘要 |
PROBLEM TO BE SOLVED: To prevent seizure caused by the overload of a motor by arranging this protector as to issue an alarm when currents are detected to get over a certain value, and to stop the motor drive when its condition continues for a certain time. SOLUTION: The voltage of a battery B is loaded to a travel driving motor M through a control circuit C built in a control box, and a drive current flows to the travel driving motor M. This drive current is detected by a motor current driving circuit Ca, and if the value is at a set value or over, this lights an alarm lamp 223 in the first place, and sounds an alarm buzzer 24, and informs a worker of the overload of a motor M. When the time of the detected current being over the set value continues of a certain time or over, the drive of the travel driving motor M is stopped to avoid the seizure caused by the overload of the traveling motor M. |
