A control assembly for controlling rotation of a turnstile, includes a torque-restoring mechanism (13) with springs (20), a motion converting transmission with a multiplying gearing (56, 57) converting a rotation of the turnstile over 120° into a rotation of the rotary shaft entering the hydraulic damper (26) over 180°. The hydraulic damper (26) has two pistons mounted onto a single piston rod. A cam or crank mechanism converts rotation of the rotary shaft into reciprocating motion of the two pistons. The first piston damps the rotary movement of the turnstile when moving in one direction while the other piston damps this movement when the pistons move in the other direction, therefore damping the turnstile in both directions. A motion converting transmission in combination with a double-piston mechanism avoids any loss of hydraulic fluid, while achieving a gradually increasing damping force to effectively stop the rotation of the turnstile.