Wireless sensor nodes (WSNs) have emerged as a crucial technology for IoT applications, with power management remaining a critical challenge for long-term deployment. Currently, most wireless sensor nodes rely on batteries or energy harvesting systems, which often suffer from limited lifespan and unreliable power delivery. While inductive charging offers a promising solution, existing systems face efficiency losses and complexity issues in their power amplification stages. This paper presents a novel Class B amplifier-based inductive charging system designed specifically for wireless sensor nodes. The main objective is to develop a high-efficiency, cost-effective charging solution that maximizes power transfer while minimizing circuit complexity. The proposed system incorporates an enhanced Class B amplifier topology to leverage an adaptive operational amplifier mechanism and produce a precisely controlled trapezoidal gate drive signal for semiconductor switches. The novel circuit architecture mitigates crossover distortion, substantially improving power conversion performance. Experimental results demonstrate that the system achieves a power transfer efficiency of up to 98 % at a 2 mm charging distance. The combined standard uncertainty in efficiency was calculated as ±0.5 %, derived from statistical analysis of repeated measurements, instrumentation accuracy, and environmental factors. Additionally, the simplified circuit design size approximately 40 x 60 mm, makes the design particularly promising for low-power applications while maintaining stable operation across varying load conditions. These findings suggest that Class B amplifier-based inductive charging systems offer a viable path toward more efficient and practical wireless power solutions for WSNs.