Bidirectional Sensor Circuit for Ground-Independent Current Sensing

The patent introduces operational amplifiers as intermediary devices between the diode rectifier circuit and the measurement system. These amplifiers buffer and amplify the rectified signal, isolating the measurement process from the voltage drop effects in the diodes. The operational amplifiers act as mediators that transfer the rectified signal while compensating for voltage losses, thereby maintaining measurement precision despite the presence of diode voltage drops.

The patent implements virtual ground references through operational amplifier circuits that create equipotential points across different ground levels. By using feedback mechanisms, the circuit maintains equal potential at critical nodes despite physical ground reference differences, enabling accurate bidirectional measurements across isolated ground domains. This approach allows the sensing circuit to operate correctly even when connected to different ground potentials.

The patent replaces the Hall effect sensor's inductive measurement mechanism with an impedance-based sensing approach using operational amplifiers. Instead of relying on magnetic field induction that suffers from inductive reverse voltage at high frequencies, the circuit uses voltage division and operational amplification through impedance networks. This substitution eliminates the frequency-dependent inductive effects while maintaining measurement accuracy across a broad frequency range.

The patent introduces ground reference correction circuits as intermediary systems that measure and compensate for ground potential differences introduced by protection impedances. These correction circuits use additional sensing elements and feedback mechanisms to detect ground reference misalignment and actively adjust the measurement reference level, thereby maintaining accurate measurements even when protection impedances create ground potential differences.