Conditioner circuit for magnetic field sensor

A circuit arrangement for measuring a magnetic field including:

• a saturable inductor for sensing a magnetic field to be measured;
• an oscillator circuit connected to said inductor for driving said inductor with a voltage waveform that causes current flow in the inductor to saturate the inductor in opposite directions in successive half-cycles, said oscillator circuit includes means switchable between two states to generate said voltage waveform;
• means connected to said inductor to generate an output signal representing the unbalance of saturation in successive half-cycles due to the magnetic field, wherein the improvement comprises:
• said inductor is connected in a circuit path through which the inductor current flows and including current sensing means connected to said switchable means to develop a current-dependent signal causing switching of said switchable means to generate said voltage waveform, and a virtual ground point provided by said output means, said output means being responsive to the current at said virtual ground point.

A circuit arrangement for measuring a magnetic field comprising:

• a saturable inductor for sensing a magnetic field to be measured;
• an oscillator circuit connected to said inductor for driving said inductor with a voltage waveform that causes current flow in the inductor to saturate the inductor in opposite directions in successive half cycles;
• means including a current-to-voltage converter connected to said inductor to generate an output signal representing the imbalance of saturation in successive half-cycles due to the magnetic field to be measured;
• said oscillator circuit is operable to drive said inductor to produce an average current in the inductor per oscillator cycle which is a measure of said imbalance, and
• said current-to-voltage converter is connected in a circuit path through which inductor current flows and is responsive to said average current in the inductor to generate a voltage representing said average current.

A circuit arrangement for measuring a magnetic field comprising:

• a saturable inductor for sensing a magnetic field to be measured;
• an oscillator circuit connected to said inductor for driving said inductor with a voltage waveform that causes current flow in the inductor to saturate the inductor in opposite directions in successive half-cycles, said oscillator circuit includes means switchable between two states to generate said voltage waveform;
• means connected to said inductor to generate an output signal representing the unbalance of saturation in successive half-cycles due to the magnetic field;
• said inductor is connected in a circuit path through which the inductor current flows and including current sensing means connected to said switchable means to develop a current-dependent signal causing switching of said switchable means to generate said voltage waveform, and a virtual ground point provided by said output means, said output means being responsive to the current at said virtual ground point.