Magnetometer with time coded output of measured magnetic fields

Magnetometer for time coded measurement of constant magnetic fields, comprising at least one sensor having

• a horizontally disposed magnetizable rod-shaped core (20) and
• a winding (19) disposed on the core (20), the winding carrying an alternating current for generating an auxiliary alternating magnetic field which magnetizes the core up to and into saturation alternately in each of two directions and, together with the magnetic field that is to be measured, generates a measurement voltage (U.sub.m), the positive and negative half-waves of which deviate from one another as a function of the magnetic field that is to be measured,
• wherein
• a triangle generator (17) is provided, which generates an alternating triangular voltage (U.sub.h) at one output thereof;
• a controlled alternating current source (18) is provided, having an input connected to an alternating triangular voltage output (U.sub.h) of said triangle generator (17) and outputs connected to respective ends of said winding (19) for generating said auxiliary alternating field;
• a single winding (19) serves both to generate the auxiliary alternating field and to generate the measurement voltage (U.sub.m), the winding having first and second ends,
• an evaluation circuit (12, 13, 21-25) is provided for evaluating the measurement voltage (U.sub.m) that can be picked up at said single winding (19);
• the first end of said winding being connected to said controlled alternating current source (18) and
• the second end of said winding being connected to said evaluation circuit (12, 13, 21-25);
• one output of the triangle generator (17) and one end of the winding (19) are applied to a common reference voltage level;
• said first end of said winding (19) is at reference voltage level and said second end is not at reference voltage level;
• a subtracting amplifier (21), having first and second inputs, is provided for evaluating the measurement voltage (U.sub.m);
• said second end of said winding (19) is connected to said second input of said subtracting amplifier (21);
• said triangle generator (17) has a first output that is at reference voltage level and a second output that is not at reference voltage level, and
• said second output of said triangle generator is connected with said first input of the subtracting amplifier.