Hydraulic control circuit for hydraulic motor

A hydraulic control circuit operable with at least two displacements for a hydraulic motor comprises a proportional speed control valve with a control valve spool continuously movable by means of a force generated by a pilot pressure controlled by a continuously electrically adjustable pilot valve having an electric actuator, wherein the control valve spool is movable between a full torque end position, a reduced torque end position, and at least one intermediate position. A time-dependent control current function is provided for controlling the current applied to the electric actuator in order to control the pilot pressure, the function including a pre-current portion having a constant non-zero current and a current ramp portion during which the current continuously rises or drops from a ramp start current level to an intermediate current level. The current suddenly changes to the switching current level at the end of the current ramp portion to allow the speed control valve spool to move from one of the two