Survey of DC current measurement techniques for high current precision power supplies

The authors investigate the various current measurement techniques typically found in the precision DC current regulated power supplies used in particle accelerator applications. The relative strengths of each type are indicated. Three basic categories of devices are discussed: current shunts, magnetic current sensors, and DC current transformers. The examined devices exhibit a variety of characteristics. The dominant factor affecting the precision of a current measurement device is its sensitivity to temperature. Long-term stability, repeatability, linearity, line voltage sensitivity, leakage flux sensitivity, and signal level will also affect the choice of a current measurement device.<>