Speed and direction recorder for agricultural vehicles - uses tachometric generators coupled to opposing wheels and controlling stepper motors

摘要

The speed of movement of an agricultural vehicle is measured from wheel rotation via tachometric generators. Graphical recording indicates speed and also direction of movement. The tachometric generators (1, 2) are connected (3) to opposing wheels of a pair to provide a voltage proportional to rotational speed. Electronic devices (4, 5) average tachometer outputs and provide conversion of outputs to frequency to control step motor (6). A difference signal is obtained to give directional orientation of vehicle. This signal drives another step motor (7) whose shaft (8) controls position of first step motor which in turn drives a recording cylinder (12).