摘要 |
<p>A measuring transformer comprises a measuring conductor carrying the current Im to be measured, a pre-magnetizing winding which carries a pre-magnetizing current Iv, and a magnetic field comparing means which is exposed to the magnetic field produced by the current Im and the magnetic field produced by the pre-magnetizing current Iv and is alternately controlled in both directions of saturation. The magnetic field comparing means is a magnetic film which may be anisotropic, operated in the magnetic preferential direction, and have a thickness of at most a few microns. It may be secured to pole shoes of a magnetic core or arranged between a flat measuring conductor and a pre-magnetizing coil of flat cross-section. The measuring transformer can be used as an input transformer in a static electricity meter. In a further embodiment, the output pulses can be obtained directly from the magnetic field comparing means.</p> |