根据分布式电磁探测仪器野外勘探的实际需求,利用通用分组无线服务技术(GPRS,general packet radio service)设计了无线网络监控系统。开发了基于VC的数据中转、监控服务器和基于Android平台的手机TCP/IP客户端,实现了电磁采集站间的数据交换、手机查看数据、数据质量分析以及对电磁采集站的远程监控,为三维、大面积、多道数、长时间的电磁探测任务提供完善的监控手段,提高了野外施工效率并为获得高质量勘探数据提供了保障。
To suppress peak voltage on rectifier diodes in a full bridge( FB) converter,the mechanism of peak voltage was analyzed and an improved FB converter was proposed. One reason for peak voltage is the resonance of the transformer's leakage inductance and the rectifier diodes' junction capacitances. The other reason is that the fast reverse recovery current of the rectifier diodes flows through the transformer's leakage inductance. An H bridge composed of four diodes,an auxiliary inductance, and a clamping winding were adopted in the proposed converter,and peak voltage was suppressed by varying the equivalent inductance, principally in different operating modes. Experimental results demonstrate that the peak voltage of rectifier diodes decreases by 43%,the auxiliary circuit does not lead to additional loss, and the rising rate, resonant frequency,and amplitude of the rectifier diodes' voltage decrease.Peak voltage and electromagnetic interference( EMI) of rectifier diodes are suppressed.
