Voltage Sensing Circuit Feedback Loop Reduces Gain Drift

The patent implements a feedback mechanism where the modulator receives the output of the voltage-to-current converter and feeds it back to the input of the converter. This feedback loop continuously corrects for gain drift by comparing the modulated signal with the original input signal, thereby maintaining measurement precision while preserving the anti-aliasing benefits of modulation and demodulation.

The patent employs periodic chopping signals for modulation and demodulation. The modulator uses a chopped signal to modulate the input voltage, and the demodulator uses a synchronized chopped signal to demodulate the converted current. This periodic action enables frequency-based signal separation that improves anti-aliasing performance while the feedback mechanism compensates for any gain drift that occurs during these periodic operations.

The feedback connection from the modulator output back to the voltage-to-current converter input creates a closed-loop system. This loop continuously monitors the converter's output and adjusts the input signal accordingly, compensating for gain drift that occurs over time. The feedback ensures that the signal transformation accuracy is maintained despite the inherent gain instability of the voltage-to-current converter.

The patent changes the operating parameters of the voltage-to-current converter by modulating its input signal with a chopped waveform. This parameter change transforms the DC or low-frequency signal into a high-frequency AC signal, allowing the converter to operate in a regime where gain drift has less impact. The subsequent demodulation recovers the original signal while the feedback loop maintains accuracy.

The integrator processes the demodulated current signal that has been recovered through periodic demodulation. By integrating over complete cycles of the chopped signal, the integrator achieves accurate signal summation while the periodic nature of the demodulated signal ensures that noise components average out rather than accumulate, reducing the harmful noise effect.

The modulator acts as an intermediary between the integrator and the voltage-to-current converter. It transforms the integrated current signal back into a voltage signal that can be fed back to the converter input. This intermediary function allows the integrator to perform accurate signal summation while the modulator prevents noise accumulation by maintaining signal integrity through the feedback loop.