Control mechanism for lifts has current test unit determining current strength of motion control unit and sending this to logic circuit for comparison to trigger counter measures if determined current strength is unusual

摘要

The control mechanism has a motion control unit (3) supplying the electrical energy required to operate the electric motor (2) which sets the ball pulley spindle (1) in rotation to move the cabin (9) up and down. A current test unit (4)determines the current strength of the motion control unit and sends this to a logic circuit unit (5) which compares the current strength determined and received from the current test unit with a current strength at a predetermined point so that counter measures can be taken if the determined current strength is unusual. The logic circuit unit is a memory-programmable control.