Resonance Inspection Probe Isolation for Parasitic Capacitance Control

A grounding subassembly with galvanically isolated grounds is introduced as an intermediary between the sense and drive piezoelectric transducers. This subassembly includes a first ground connected to the sense transducer and a second ground connected to the drive transducer, with the grounds being galvanically isolated from each other. This intermediary grounding structure provides a reference potential for both transducers while preventing parasitic capacitance coupling, thus resolving the measurement interference problem while maintaining compact probe design.

The grounding subassembly merges the grounding functions for both the sense and drive circuits into a single integrated structure. Rather than implementing separate grounding systems, the subassembly combines both grounds with their galvanic isolation in one compact unit that connects to both transducers, thereby achieving precise measurement while minimizing the increase in device complexity.

The patent replaces complex transformer-based parasitic capacitance compensation circuits with a simpler galvanically isolated grounding subassembly. Instead of using transformers to actively compensate for parasitic capacitance effects, the invention uses a passive galvanic isolation structure that inherently prevents parasitic capacitance coupling between the sense and drive circuits, thereby achieving reliable defect detection with reduced device complexity.