Abstract: The invention relates to a circuit arrangement for controlling electric motors of an industrial truck, comprising an electronic control stage with a main board (16) and an exchangeable board (22), and comprising a power-output stage (14). The exchangeable board (22) can be detached with little effort from the main board (16) that is fixed inside a case (12). The exchangeable board (22) comprises a group of selected control stage components (24) for which, statistically, a greater need for exchanging and/or a greater need for testing and/or a greater need for variants to be kept ready on the side of the producer exists than for the components (18) of the main board (16).

Abstract: An industrial lift truck with a load lifting device (15), a device (3, 9, 11) for moving the load lifting device (15) on the lift truck (1) having at least one element (7) that can move, together with the load lifting device (15), along an essentially straight guide (5), and with a position measuring device for monitoring the relative position to the guide (5) of the element (7) movable with the load lifting device (15).

Abstract: In a circuit for supervising the wear of carbon brushes making normally contact with a commutator of a direct-current electric motor of an electrically operated vehicle powered by an accumulator, and which includes main on-off switch for starting and stopping the vehicle, electrically insulated control brushes carried by the carbon brushes, and movable therewith, and a warning signal indicator normally connected to the control brushes, which provides a selectable optical and acoustic warning signal when the control brushes establish contact with the commutator upon a predetermined degree of wear of the carbon brushes, the improvement includes an electrical memory which has set and reset inputs, is connected to the control brushes, and controls the warning signal indicator. The control brushes set the memory upon establishing contact with the commutator.