JPH02145292U - - Google Patents

Description

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention;
FIG. 2 is a circuit diagram showing a second embodiment of the present invention, FIG. 3 is a configuration diagram showing an inverter hoist, and FIG. 4 is a circuit diagram showing a conventional technique. In the drawing, 1 is a three-phase power supply, 2 is a hoisting motor, 3 is a hoisting brake, 4 is an inverter, 6 is a rise switch, and 7 is a fall switch.

Claims (1)

[Scope of claim for utility model registration] Whether a hoisting motor that is supplied with AC power and driven to rotate, an inverter that is supplied with power from a commercial power source and outputs an AC current with a higher frequency than the frequency of the commercial power supply, and a suspended load are added. It includes a load sensor that detects a rise switch, a fall switch, and various relays, and when it is determined by the load sensor that no load is applied, turning on the rise switch removes the hoisting from the inverter. By sending an alternating current to the electric motor to cause the hoisting motor to rotate in the normal direction and turning on a lowering switch, alternating current is sent from the inverter to the hoisting motor to reverse the hoisting motor, while the load is detected by the load sensor. If it is determined that the hoisting motor is connected to the hoisting motor by turning on the up switch, the commercial power source is connected to the hoisting motor and the hoisting motor is rotated in the normal direction, and the commercial power is turned on by turning on the down switch. An inverter hoist comprising: a sequence circuit connected to an upper motor to reverse the hoisting motor;