Welcome to the Tamura Corporation Current Sensor training module. This module will explain the basic operation and applications of closed loop type Hall Effect current sensors and their applications in power electronics. The closed loop Hall Effect current sensor is sometimes referred to in several ways: Zero-Flux Sensor, Compensation Sensor, DC-CT, or Null Sensor. It is fundamentally a feedback element used in a control system that provides a very accurate current measurement as a means to optimize system performance.