Abstract: The present invention provides a liquid level sensor and an automatic calibration process which removes the need for prior manual calibration of the liquid level sensor, as this happens dynamically during installation and use of the pump. Further, by frequently monitoring the calibration of the sensor and correcting for long term drift or contamination on the sensing surface, the reliability of the liquid level sensor is considerably better than those of the prior art. By operating a solid state sensor, there are no moving parts in the liquid level sensor described above.

Abstract: There is provided a condensate pump assembly (100) for use in an air conditioning system. The condensate pump assembly (100) comprises a pump (102) arranged in a housing (104) to pump liquid from a liquid inlet (116) towards a liquid outlet (106). The condensate pump assembly (100) further comprises a liquid receptacle (108) arranged, in a first position in the housing (104), to receive condensate from a condensate inlet (110) and to be in fluid communication with the liquid inlet (116). The liquid receptacle (108) is movable to a second position removed from the housing (104), whereby to empty the liquid receptacle (108). The condensate pump assembly (100) further comprises selective release (112, 114) means operable by a hand of a user to release the liquid receptacle (108) for movement from the first position towards the second position.

Abstract: A pulsation damper for a condensate pump comprising a housing defining a fluid chamber having a liquid inlet connectable to an outlet of the condensate pump, an air inlet, and a liquid outlet, wherein the air inlet includes a one-way valve configured to selectively introduce air into the housing to maintain a first air pocket within the fluid chamber as liquid flows through the fluid chamber, wherein the liquid outlet is located outside the first air pocket, and wherein the air pocket is configured to dissipate pulsations within liquid entering the housing at the liquid inlet prior to the liquid discharging via the liquid outlet.

Abstract: The present invention provides a liquid level sensor and an automatic calibration process which removes the need for prior manual calibration of the liquid level sensor, as this happens dynamically during installation and use of the pump. Further, by frequently monitoring the calibration of the sensor and correcting for long term drift or contamination on the sensing surface, the reliability of the liquid level sensor is considerably better than those of the prior art. By operating a solid state sensor, there are no moving parts in the liquid level sensor described above.

Abstract: The present invention provides a liquid level sensor and an automatic calibration process which removes the need for prior manual calibration of the liquid level sensor, as this happens dynamically during installation and use of the pump. Further, by frequently monitoring the calibration of the sensor and correcting for long term drift or contamination on the sensing surface, the reliability of the liquid level sensor is considerably better than those of the prior art. By operating a solid state sensor, there are no moving parts in the liquid level sensor described above.

Abstract: There is provided a condensate pump assembly (100) for use in an air conditioning system. The condensate pump assembly (100) comprises a pump (102) arranged in a housing (104) to pump liquid from a liquid inlet (116) towards a liquid outlet (106). The condensate pump assembly (100) further comprises a liquid receptacle (108) arranged, in a first position in the housing (104), to receive condensate from a condensate inlet (110) and to be in fluid communication with the liquid inlet (116). The liquid receptacle (108) is movable to a second position removed from the housing (104), whereby to empty the liquid receptacle (108). The condensate pump assembly (100) further comprises selective release (112, 114) means operable by a hand of a user to release the liquid receptacle (108) for movement from the first position towards the second position.

Abstract: A pulsation damper for a condensate pump comprising a housing defining a fluid chamber having a liquid inlet connectable to an outlet of the condensate pump, an air inlet, and a liquid outlet, wherein the air inlet includes a one-way valve configured to selectively introduce air into the housing to maintain a first air pocket within the fluid chamber as liquid flows through the fluid chamber, wherein the liquid outlet is located outside the first air pocket, and wherein the air pocket is configured to dissipate pulsations within liquid entering the housing at the liquid inlet prior to the liquid discharging via the liquid outlet.

Abstract: The present invention provides a liquid level sensor and an automatic calibration process which removes the need for prior manual calibration of the liquid level sensor, as this happens dynamically during installation and use of the pump. Further, by frequently monitoring the calibration of the sensor and correcting for long term drift or contamination on the sensing surface, the reliability of the liquid level sensor is considerably better than those of the prior art. By operating a solid state sensor, there are no moving parts in the liquid level sensor described above.

Abstract: A method of driving a solenoid pump of the type comprising a metal shuttle urged by a solenoid against a spring with the spring providing the force for the pumping stroke of the shuttle is disclosed. The method comprises applying a periodic driving voltage to the solenoid. Each period of the driving voltage comprises a first portion during which the driving voltage increases from a minimum voltage to a maximum voltage to compress the spring, a second portion during which the driving voltage decreases from the maximum voltage to the minimum voltage to release the spring, and a third portion during which the driving voltage is maintained at the minimum voltage. The duration of the second portion is substantially less than the duration of the first portion and may be substantially instantaneous. The driving voltage increases from the minimum voltage to the maximum voltage substantially linearly during the first portion, such that the driving voltage has a sawtooth waveform.