signal 28 39 is less than or equal to some predetermined rate will produce a shaped signal 29 39 which is the same in amplitude as control signal 28 39 however when control signal 28 39 varies at a rate exceeding this predetermined rate as in the case of control signal 28 39 at time t 1 shaper 29 produces a signal 29 39 which does not drop in voltage as rapidly as does control signal 28 39 in fact it can be seen that signal 29 39 only reaches 0 at time t 2 which is later than t 1 and only reaches the negative voltage of control signal 28 39 at an even later time t 3 hence it may be seen from fig2 b that the shaper 29 extends the time during which the direction of operation and speed of operation of the loads are to change referring now to fig1 in more detail it can be seen that it is the shaped signal 29 39 which actually serves to operate the system herein shaped signal 29 is utilized in two fashions its magnitude determines the speed at which the loads are to operate and its direction determines the direction in which the loads are to operate thus the rest of the electronics control system is divided into two sub systems a directional sub system and a pressure sub.