摘要 |
PURPOSE: An overload restricting apparatus for a crane is provided to prevent accidents and alarm danger by detecting overload of the crane and operation of the crane and calculating operational time of the crane. CONSTITUTION: A microcomputer(11) is connected to a memory(18), a key input unit(19), an alarm unit(20), a high speed motor driving unit and a low speed driving unit. The high speed motor driving unit has an overload detecting circuit(12), a motor switching unit(13) and a brake switching unit(14), and the low speed motor driving unit has an overload detecting circuit(15), a motor switching unit(16) and a brake switching unit(17). The microcomputer checks overload detecting circuits through control program, controls the motor and the brake by switching units, and prevents overload by driving the alarm unit and controlling overload.
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