Abstract: A linear actuator includes a casing that contains a moveable shaft moved by a motor in response to a drive signal and coupled to an encoder that determines an actual instantaneous position of the shaft and forms part of a control loop that adjusts the drive signal so as to ensure accurate positioning of the shaft. A temperature sensor mounted on the shaft produces a temperature signal indicative of instantaneously measured temperature, and a temperature compensator responsive to the measured temperature for generating a negative or positive offset for correcting the drive signal so as to move the shaft to a positon that is corrected for instantaneous expansion or contraction of the shaft owing to departures of the shaft's actual temperature from a known baseline temperature.

Abstract: A linear actuator includes a casing that contains a moveable shaft moved by a motor in response to a drive signal and coupled to an encoder that determines an actual instantaneous position of the shaft and forms part of a control loop that adjusts the drive signal so as to ensure accurate positioning of the shaft. A temperature sensor mounted on the shaft produces a temperature signal indicative of instantaneously measured temperature, and a temperature compensator responsive to the measured temperature for generating a negative or positive offset for correcting the drive signal so as to move the shaft to a positon that is corrected for instantaneous expansion or contraction of the shaft owing to departures of the shaft's actual temperature from a known baseline temperature.

Abstract: Pool alarm system for detecting the introduction and/or presence of a body in a liquid pool. The system includes: a first sensor for sensing audio signals generated by the body in the pool; a second sensor for sensing water pressure signals generated by the body in the pool; an analog signal processor for pre-processing the audio signals and water pressure signals and for converting them to digital data; an alarm device activated when the body was detected in the pool; a processor and control unit. The audio signals are detected and processed faster than the detection of the water pressure signal. According to the intensity of an acoustic signature originating from the audible signals an aquatic signature originating from the water pressure sensor is analyzed using an adaptable sensitivity parameter dependent on the intensity of the acoustic signature for improving alarm triggering decision.

Abstract: Pool alarm system for detecting the introduction and/or presence of a body in a liquid pool. The system includes: a first sensor for sensing audio signals generated by the body in the pool; a second sensor for sensing water pressure signals generated by the body in the pool; an analog signal processor for pre-processing the audio signals and water pressure signals and for converting them to digital data; an alarm device activated when the body was detected in the pool; a processor and control unit. The audio signals are detected and processed faster than the detection of the water pressure signal. According to the intensity of an acoustic signature originating from the audible signals an aquatic signature originating from the water pressure sensor is analyzed using an adaptable sensitivity parameter dependent on the intensity of the acoustic signature for improving alarm triggering decision.