Abstract: A device for constant, automatic regulation of water pressure and flow in a water supply plant, comprising an electric pump fitted in the main water pipe, an adjustable pressure switch connected to the main water pipe, and an electronic control unit, which switches the pump on if the pressure falls short of a predetermined level or switches it off if a predetermined pressure level is exceeded. The device is characterized in that a turbine, incorporated in the water pipe, acts as a sensor, cooperating with a rotation signal transmitter which is connected to the electronic control unit in order to keep the pump switched on as long as the sensor detects a flow of water.

Abstract: In a magnetically suspended type pump, an operating state of the pump can be obtained without using a pressure gauge and a flowmeter. In addition, in the case where the magnetically suspended type pump is applied to a blood pump, in order to reduce the number of connections in a flow path and to avoid thrombus formation, a correlation between current flowing in a motor and flow or a correlation between current flowing in the motor and pressure is obtained in advance, and the speed of rotation of motor is varied by a speed of rotation control circuit in response to an instruction from a CPU circuit, based on the obtained correlation between current and flow or between current and pressure, whereby flow or pressure is controlled.

Abstract: A sensor can detect the difference in potential between a probe and the fluid into which it is immersed, and a signal generated by the probe representing this difference in potential is used to activate an oscillator circuit. By varying the conditions at which current in the oscillator circuit begins to oscillate, various liquids can be detected and identified.

Abstract: Protective apparatus in a scroll compressor, in the form of a valve assembly, is operative to prevent compressor damage from reverse direction rotation of the scroll compression mechanism or the development of abnormally high discharge gas temperatures. The valve assembly is disposed in a passage communicating between the suction and discharge pressure portions of the compressor shell and houses a discharge temperature sensor immediately adjacent the location from which discharge gas issues from the compression mechanism. The location of the sensor and its exposure to discharge gas permits the timely sensing of abnormally high discharge temperatures and the shutdown of the compressor upon their occurrence.