High-impedance control source for saturable reactor

THIS ANALYSIS is based on core materials whose magnetic property can be approximated by a rectangular flux-density field-intensity curve. The control source is considered of high impedance when alternating currents are practically nonexistent in the control circuit. This condition is encountered in practice in saturable reactors used for the measurement of large directcurrents, and also in the constant-current standard where the d-c control winding is replacedby a permanent magnet.