Flowmeter comprising an electronic magnetic sensor with buffered power supply

A magneto-sensitive unit for use with a flow meter having a movable element which is moved by a flow of a fluid and which comprises at least one movable magnetic element, the unit comprising:

• two terminals, namely a signal terminal and a reference terminal;
• a magnetic sensor element having two output terminals connected to the signal terminal and the reference terminal, respectively, of the magneto-sensitive unit and a power supply terminal;
• and
• a buffered power supply unit connected to the signal terminal and the reference terminal of the magneto-sensitive unit, and configured to generate a continuous auxiliary voltage from the signal terminal and the reference terminal of the magneto-sensitive unit and to provide the continuous auxiliary voltage at the power supply terminal of the magnetic sensor element;
• wherein the magneto-sensitive unit is configured to assume a first state providing a high resistance between the signal terminal and the reference terminal to generate a first digital signal level at the signal terminal when a magnetic field or flux applied by the movable magnetic element corresponds to a first condition, and to assume a second state providing a low resistance or short circuit between the signal terminal and the reference terminal to generate a second digital signal level at the signal terminal when the magnetic field or flux applied by the movable magnetic element corresponds to a second condition;
• and
• wherein the magneto-sensitive unit is configured to oscillate between a fourth and a fifth state with a predetermined frequency and/or a predetermined pulse duty factor when the movable element is stopped so that the magnetic field or flux applied by the movable magnetic element continuously corresponds to the second condition, wherein the fourth state provides a resistance between the signal terminal and the reference terminal generating the first digital signal level at the signal terminal and the fifth state provides a resistance between the signal terminal and the reference terminal generating the second digital signal level at the signal terminal.