| 摘要 |
PURPOSE:To permit a previously set crane to control-work additionally with simple connection working in the field, by inserting a circuit including an inverter and a second switch as a unit, into the front stage of the motor of the crane. CONSTITUTION:A DC power circuit 8, an inverter 5, and a second switch 6 are inserted into a new power circuit 4 branched from a power circuit 1 and connected to a motor 7. To the excitation coils 2F, 2R of a relay opening or closing a main switch 2, the excitation coils 3F, 3R of a control relay are connected in parallel with each other, and control signal from the contacts 3b, 3r of the control relay is applied to the inverter 5 and the second switch 6. By the previously set crane motor 7 to which a circuit 10 surrounded with a dotted line is added, the new control working of slow start, slow stop, low- speed operation or the like can be performed. |
