Abstract: A warning device is energized when speed signals integrated in an integrator exceed a predetermined level. However if a steering wheel and/or an accelerator pedal is operated, the integrator is reset.

Abstract: A constant voltage developed by a constant voltage generator is integrated, and the integrated voltage is applied to a voltage comparator. A standard voltage is applied to a voltage controller, which includes a sensor responsive to vehicle operating conditions, to control the level of the standard voltage to indicate the degree of driver alertness necessitated by the vehicle operatingconditions. The controlled standard voltage is also applied to the voltage comparator, and when the integrated voltage exceeds the controlled standard voltage the comparator develops a warning signal output. A warning device receives the warning signal and is thereby rendered operative in order to alert the driver.

Abstract: Herein disclosed is an automotive power-assisted steering system which comprises a hydromechanical leverage unit drivingly connected to a steering linkage, a rotary piston-valve hydraulically connected to the leverage unit, a motor to move the piston-valve for actuating the leverage unit to a right-turn or left-turn position, and a valve re-set mechanism connected between the leverage unit and the piston-valve for moving the valve into an equilibrium position from a condition bringing the leverage unit into the right-turn or left-turn position, wherein the motor is energized by a pulsating current which is controlled in accordance with a signal representative of the angle and direction of turning of a steering wheel and, where desired, signals representative of a vehicle velocity and an external force which may be sideways imparted to the vehicle by a side wind blowing onto the vehicle.