Novel zero ripple DC current transformer design

A new circuit of DC ripple-free current transformer (DCCT) is proposed to achieve the high-accuracy, the high-speed, the high-reliability and the no hysteresis effect in sensing of current for power electronic applications. This DCCT consists of two phase (opposite phase) transistor-core-based multivibrators synchronized to clock pulses with built-in oscillators. In this paper, the operating principle and experimental results, both on static and dynamic characteristics are presented. Moreover, the response time of 2 /spl mu/sec under 3 kHz of clock pulse is also reported.