Valve system for regulating the idling speed of Otto engines, particularly automobile engines

In a valve arrangement system for regulating the idling speed of Otto engines, particularly automobile engines, by controlling the amount of air on an outlet side having suction vacuum with an electromechanical setting member which comprises a valve element which limits an effective outlet cross section, the valve element being moveable by an electric drive member and being in communication on one side with the outlet side, and having a circuit which operatively controls the setting member as a function of the speed of rotation, the improvement wherein

• the valve element is mounted substantially free of friction,
• compensation means for exerting on the valve element a compensating force which opposes the force caused by the suction vacuum,
• an rpm transducer providing a variable signal dependent on the actual rotational speed of the engine,
• said circuit includes,
• a first difference amplifier having one input acted on by an electric value corresponding to the desired idling speed and another input operatively connected to said rpm transducer,
• said first difference amplifier having an output connected to said electric drive member,
• a differential amplifier means for connecting said rpm transducer to said first difference amplifier and having a differential portion which is switchable to effectiveness upon a reduction in the speed and to inactive upon an increase of the speed.