Abstract A low-power open-loop self-oscillating fluxgate current sensor based on Mn-Zn soft ferrites is proposed in the paper. Differential realization of compensation amplifier, in class-D full-bridge configuration, provides full theoretical reduction of power consumption, which is impossible in the case of standard half-bridge realization. Together with data provided from the ferrite manufacturers, offered set of simple equations can qualitatively estimate quiescent and operating power consumption, and help in avoidance of design solutions that lead to unnecessary power losses. If a commercial or custom transformer core, made of conventional industrial Mn-Zn ferrite materials is used, all important parameters for sensor design, and follow-on exploitation, can be predicted in advance. Experimental examinations show that power consumption can be reduced to the level of open-loop Hall-effect based sensor, while many comparable advantages of flux-gate technology are maintained. We design sensor and tuned circuit parameters to measure currents in the range of [–20 A, 20 A] with an overcurrent capability of 50%. In temperature range of [–20 °C, 50 °C], maximum relative linearity error of 0.25% and offset drift of 0.05% is achieved.

中文翻译：

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基于Mn-Zn铁氧体磁芯的低功耗自激磁通门电流传感器

摘要 本文提出了一种基于Mn-Zn软铁氧体的低功耗开环自激磁通门电流传感器。在 D 类全桥配置中，补偿放大器的差分实现提供了完全理论上的功耗降低，这在标准半桥实现的情况下是不可能的。结合铁氧体制造商提供的数据，提供的一组简单方程可以定性地估计静态和工作功耗，并有助于避免导致不必要功耗的设计解决方案。如果使用由传统工业 Mn-Zn 铁氧体材料制成的商用或定制变压器磁芯，则可以提前预测传感器设计和后续开发的所有重要参数。实验检验表明，功耗可以降低到基于开环霍尔效应的传感器的水平，同时保持了磁通门技术的许多可比优势。我们设计传感器和调谐电路参数来测量 [–20 A, 20 A] 范围内的电流，过流能力为 50%。在 [–20 °C, 50 °C] 的温度范围内，实现了 0.25% 的最大相对线性误差和 0.05% 的偏移漂移。