A current-controlled variable-inductor for high frequency resonant power circuits

The practicality of designing a bias-controlled inductor, suitable for high frequency resonant mode inverters and converters, was investigated theoretically and experimentally. The proposed variable inductor is built around a double `E´ core structure with zero mutual coupling between the main inductor windings and the bias windings. The theoretical analysis of this study lead to a simple equivalent circuit and closed form equations that express the relationship between the inductance and the controlling bias current. Excellent agreement was found between model predictions and experimental results