ELECTROMAGNETIC TYPE DIGITAL CURRENT DETECTOR

摘要

PURPOSE:To reduce power loss by dispensing with not only a pulse modulating integrator but also the electrical insulation between a circuit under test to which a current under test flows and a test circuit by utilizing the integrating element of the winding wound around a toroidal core. CONSTITUTION:A part of the magnetic path of a toroidal core 103 having measuring winding 102 to which an AC or DC under test flows and compensation winding 101 introducing a carrier pulse to make the output of a current under test modulated in pulse width synchronous to the carrier pulse wound therearound is opened and a Hall element 104 is provided to the opened part. A constant current is applied to a pair of the end surfaces of the element 104 from a DC-power supply 120 through a constant current circuit 121 and the voltage corresponding to the change of the magnetic flux crossing the element 104 is generated in a pair of the other end surfaces thereof. Since the integrating elements of the windings are utilized by allowing the current under test of analogue quantity to flow to the test winding 102 of the toroidal core, a pulse width modulating A/D converter can be dispensed with.