ELECTRONIC CONTROLLER FOR AUTOMOTIVE AIR CONDITIONING SYSTEM

摘要

An automotive air conditioning system including a compressor, a condenser and an evaporator core over which air is directed and cooled for return to the passenger compartment of the car. The evaporator core is maintained at approximately 32 DEG F. by the combined control of an expansion valve between the condenser and evaporator and a suction throttling valve between the evaporator and the inlet of the compressor. The expansion valve is controlled in response to the temperature of the outlet pipe of the evaporator core and the temperature of the outlet pipe from the suction throttling valve and the flow of refrigerant is metered through the valve to keep the core full of liquid refrigerant to assure maximum cooling efficiency. The suction throttling valve is controlled by sensing the temperature of the outlet pipe from the evaporator core and controlling a throttling piston by means of a transducer for converting electrical energy into mechanical movement of the throttling piston to maintain an evaporator pressure at a constant pressure of 29.5 psi plus or minus 0.5 psi to maintain tubes and fins of the evaporator core at approximately 32 DEG F.