瞬变电磁发射机的无源恒压钳位技术

Passive constant pressure clamping technology for transient electromagnetic transmitter

传统的准谐振和电压源恒压钳位方法可以使电流关断延时减小,电流下降线性度变好。但其控制电路比较复杂,且均引入了电容,容易和线圈发生谐振而使电流下降沿两端的抖动加剧。为此提出了用TVS和SIDAC器件来实现无源恒压钳位电路。这样不仅可以使电路简单,而且由于2种器件的结电容较小,电流下降沿两端的抖动也较小。对2种器件来实现恒压钳位电路进行了分析,表明2种器件设计的电路均能满足恒压钳位的要求。实验结果表明:无源恒压钳位方法可以使电流下降线性度好,下降沿两端抖动小,且电路较为简单。

The traditional quasi resonant and constant pressure clamping method can make current cut-off delay shorter and linearity better.But their control circuits are complex and the introduced capacitance is easy in resonance with coils,which can aggravate jittering on the both ends of trailing edge.For this reason,it is proposed that using TVS and SIDAC devices to realize passive constant-voltage clamping circuit.It can not only make circuit simple,but also reduce jittering on the both ends of trailing edge for the lower junction capacitance in the two devices.Passive constant-voltage clamping circuit composed by TVS and SIDAC is analyzed,and it manifests that the designed circuits with two devices both meet constant pressure clamping requirements.Experimental results show that the passive constant pressure clamping method can make the current decline linearity better,jittering on the both ends of trailing edge lower and circuit simpler.