Stepper Motor Bridge Circuit for Zero-Crossing Resonance Damping

The patent introduces a diode bridge circuit as an intermediary component that enables passive fast-decay phases. The diodes act as mediators to redirect and dissipate residual coil current at zero-crossing points, providing resonance damping without requiring active control intervention. This intermediary structure resolves the contradiction by adding a passive circuit element rather than complex active control logic.

The patent implements periodic activation of fast-decay phases synchronized with the zero-crossing events of the target coil current. By triggering current decay at regular periodic intervals corresponding to each zero-crossing, the system achieves continuous resonance damping throughout operation. This periodic action approach provides effective damping without requiring complex real-time control algorithms.

The patent converts the harmful resonance effect into a beneficial damping mechanism by utilizing the natural zero-crossing moments of the coil current. Instead of trying to avoid these moments, the invention actively triggers fast-decay phases at zero-crossings, transforming what could be resonance-buildup points into resonance-damping opportunities. This approach allows high chopper frequencies for precision control while simultaneously suppressing resonances.

The patent applies preliminary damping action by activating fast-decay phases just before or at the zero-crossing points where resonances would naturally build up. By preemptively reducing residual current at these critical moments, the system prevents resonance amplification before it can occur, allowing high-frequency chopper operation without resonance issues.