toward the heat exchanger a sensor device senses an air temperature for the air flow through the heat exchanger and generates an electrical sensor signal indicative thereof a temperature selector selects a target temperature of the air flow through the heat exchanger and generates an electrical set signal indicative thereof a control circuit controls opening of the valve by integrating a feed back control and a feed forward control based on the electrical sensor signal and the electrical set signal therefore the air conditioning system is adapted for improving control response characteristics without influences from disturbances and ensures improved control to provide stable control with rapid response to achieve a target temperature or a modification to the set temperature inside of the passenger compartment or both application_number US 91761097 A description fig4 depicts an automotive air conditioning system in accordance with an embodiment of the present invention in the drawings like reference numerals are used to denote elements corresponding to those shown in fig1 an air conditioning system 10 includes a first sensor 16 for detecting air temperature 34 tin 34 at an inlet of heater core 103 which is disposed in duct 101 upstream from heater core 103 a second sensor 17 for detecting air temperature 34 to 34 at an outlet of heater core 103 is disposed in duct 101 downstream from heater core 103 first and second sensors 16 and 17 provide electrical sensor signals according to an inlet air temperature 34 tin 34 and an outlet air temperature 34 to 34 respectively to electrical control unit 18 further air conditioning system 10 includes a third sensor 19 for detecting the temperature 34 tw 34 of a fluid such as a engine coolant e g.