| 摘要 |
A high power switching circuit suitable for injection of high currents, typically several tens of Amperes, at high drive voltages of up to 5-10 kV, is provided using a combination of electromechanical 206 and semiconductor 210 switching elements that, while providing switchable polarity, substantially bypasses the semiconductor switching element during a substantial portion of current injection duty cycles. In this way, thermal heating of switching elements can be reduced/managed in a way that improves long term reliability of geophysical survey equipment. In addition, circuit protections can be provided to address backflow currents generated upon collapse of electromagnetic fields in inductive loads, such as is typical in geophysical surveys. |
