Abstract: A topside buoy system is disclosed for relaying a status of a diver between a monitoring station and a diver's wearable device and scuba tank pod. The communication may be carried by sonar signals underwater and may be transmitted by short-range communication methods through air. An application on the command station may display diver status information and may receive and transmit messages between the command station and the wearable device of the diver via the topside buoy. The diver location data may be determined relative to the topside buoy by determining a time delay of the sonar signal between the wearable device and the topside buoy, by a plurality of transducers configured to detect an angle from which the sonar signal originated, and a depth of the diver included in the sonar signal.

Abstract: In a method for the diagnosis of an air conditioning system having a condenser, an evaporator, an expansion device and a compressor, the stroke of which can be set via a valve, a maximum compressor stroke is set abruptly when the air conditioning system is running and a pressure impulse arising in the high pressure side of the refrigerant circuit is measured in order to determine the degree of filling of the refrigerant circuit.

Abstract: In a method for the temperature regulation of an air conditioning system having a condenser, an evaporator, an expansion device and a compressor, the stroke of which can be set via a valve, the temperature in the region of the air outlet of the evaporator is measured and a desired temperature is set by a controlling of the valve. The temperature regulation additionally takes place in dependence on the refrigerant pressure.

Abstract: An improved control method for an electronically controlled variable displacement refrigerant compressor, where the control has normal and high speed displacement control modes, with smooth transitions between such control modes. The displacement control mechanism is in the form of a solenoid valve, and the valve is pulse-width-modulated (PWM) at a variable duty cycle to regulate displacement of the compressor. When the compressor is operating in a normal speed range, a first control mode determines a normal PWM duty cycle to satisfy cooling demand; when the compressor is operating in a high speed range, a second control mode determines an alternate PWM duty cycle based on compressor speed. The solenoid valve is operated in accordance with the duty cycle corresponding to the lower displacement. A smooth transition from the normal control mode to the high speed control mode is achieved by scheduling the alternate duty cycle as a function of compressor speed.