Patent ID: 6018238
Filing Date: 2000-01-25
Classification: G01R

Abstract:
A current meter operable in a low frequency measurement mode and a high frequency measurement mode for measuring the flow of low and high frequency line current, respectively, through a current carrying conductor, said current meter comprising in combination:a magnetic core, said magnetic core including a first portion having a first toroidal section, a second portion having a second toroidal section, a first set of windings positioned on said first toroidal section, a second set of windings positioned on said second toroidal section and being electrically coupled to said first set of windings, and a pair of input and output terminals electrically coupled to said first and second sets of windings;a drive means including a drive circuit and a detector circuit, said drive circuit including means for providing an excitation current to said first and second sets of windings during the low frequency measurement mode, said drive circuit and said detector circuit of said drive means being electrically coupled to said pairs of input and output terminals of said magnetic core, respectively; anda switching means for changing the mode of operation of said current meter from said low frequency measurement mode to said high frequency measurement mode when the frequency of said line current exceeds a predetermined amount, said switching means being electrically coupled to said drive means to disable said drive means during high frequency measurement mode.