Up-down control
The up-down control is used to control a locomotive. Feature of the up-down control is the special traction switch with the positions 0 , From , drive and on .
The drive switch of the locomotive is selected directly with the up-down control . If the driving switch is set to move the derailleur running way up gradually. If you now switch to the drive position, the rear derailleur will remain in the drive position reached after the current shift has been completed. When the drive switch is moved to the Down position , the switching mechanism descends in stages. Here, too, the current drive level can be maintained by moving the drive switch to the drive position. If the drive switch is moved to position 0 , the power is immediately removed (the isolating contactors drop out) and the switching mechanism returns to 0. This corresponds to the quick-off function for locomotives with a drive switch handwheel-Position.
The up-down control is particularly common in electric locomotives, for example in the 111 series . However, some diesel traction vehicles, such as the DB class 612 (1998) , have this type of control.
The throttle right in the picture above has to position on the possibility of so-called Z control. It can be used to preselect a desired tensile force. The Z-control then automatically selects the speed levels with which the desired tractive effort is achieved and maintained. This function is comparable to that of the traction control in continuously variable three-phase AC locomotives.
In the 112/114/143 series , the up-down control is used to directly control the speed steps in the event of a defective main control or during maneuvering (auxiliary control). To do this, the lever on the main control rocker must be on "1". All monitoring and limiting values are bypassed except for the overcurrent limitation to 450 A. The main control itself corresponds in its functionality to the automatic drive and brake control .