Abstract: In an air conditioning system, thermistors measure evaporator inlet and outlet temperatures and compressor body temperature. When the differential between inlet and outlet temperatures is below a first threshold and the compressor temperature is above a second threshold, very low refrigerant charge is indicated and the compressor is turned off. Also, if compressor temperature reaches a critical value, the compressor is turned off regardless of the temperature differential across the evaporator.

Abstract: An integral receiver/dehydrator and expansion valve is disclosed in an automotive air conditioning system. A common housing comprises a receiver/dehydrator container surmounted by a connector body in a unitary construction. An electronically controlled expansion valve is disposed in an axial passage in the connector body and a valve chamber in the body connects the draw tube of the receiver/dehydrator to the valve orifice. An annular groove in the common wall between the connector body and the receiver/dehydrator container is connected by a radial passage through the body with the suction line of the receiver/dehydrator from the condenser. An annular chamber surrounding the valve outlet port is connected by a radial passage to the suction line of the evaporator. The radial passages may be disposed at any desired angle on the body to accommodate the connection of the receiver/dehydrator suction line and the evaporation suction line.