Magnetic-inductive flowmeter and method for operating an electromagnetic flowmeter

Magnetic-inductive flowmeter having a throughflow of an electrically conductive medium, the measuring tube (1) and a two magnet coils (3, 4) having magnet, for generating a substantially homogeneous magnetic field, the magnet coils (3, 4) are connected in series and the supply takes place of the magnet coils (3, 4) with a temporally alternating the two magnet coils (3, 4) each in the same direction passing through the field current with the aid of a four switches (5, 6, 7, 8) having the bridge circuit, wherein the alternate opening and closing of each two switches (5, 8, 6, 7) causes a reversal of polarity of the field current, characterized in that a center tap between the two coils connected in series (3, 4) is provided for generating an inhomogeneous magnetic field and the center tap of a first additional switch (9) and a second additional switch (10) is so connected to the bridge circuit that in abw echselndem opening and closing of two switches (5, 7, 6, 8) and an additional switch (10, 9), ...