Hydraulic control circuit for which the input signal (distance, rotation speed) is specified using mechanical means via a hand lever, cam disc or spindles and the like, before being hydraulically amplified. Main area of application: the now far less important copying attachment and the amplification of torque for stepper motors or DC motors by torque and linear amplifiers, in agricultural machines (e.g. ploughing depth feedback control) (Figure M 4).

Figure M 4: Hydro-mechanical force and mixing closed loop control for hoisting gear