Abstract: A noise reducing apparatus for a cyclo-fan is provided for the canceling of a whistling noise with a specific frequency, determined by the product of the rotation number of the cyclo-fan and the number of blades thereof. The apparatus comprises a cyclo-fan including a plurality of blades with arc shapes radially disposed centering the axis thereof, and a couple of supporting members for supporting both ends of the respective blade; a sensor for the passage of the respective blade at a fixed position; a controller for calculating the frequency and pressure level of a peculiar noise generated by the cyclo-fan based on the signal transmitted from the sensor, and then generating an electric signal corresponding to the interference sound having a reverse phase and same pressure level to that the peculiar noise, and a plurality of speakers for converting the electric signal from the controller into the interference sound.

Abstract: An air conditioning system includes a compressor, and indoor and outdoor heat exchangers. During a heating cycle, when the refrigerant exiting the outdoor heating exchanger comprises a mixture of gaseous and liquid refrigerant, that mixture is passed through an accumulator in which the flow speed of the refrigerant is reduced, and in which the refrigerant is heated to convert the liquid refrigerant to gaseous refrigerant.

Abstract: A burner control system for controlling loads such as a blower motor and an electronic pump of a burner which comprises a drive voltage regulating circuit for varying the drive voltages corresponding to the loads to thereby vary the amount of heat being generated from the burner in the actuated condition. A microprocessor outputs a plurality of load control signals. A drive signal generating circuit for initiating in response to the plurality of load control signals received from the microprocessor generates a plurality of drive signals for driving the loads. A driving circuit powers the loads in accordance with the plurality of drive signals from the drive signal generating circuit.