Electrical Resonance Frequency Meter

Electrical Resonance Frequency Meter Points : Electrical Resonance Frequency Meter Resonance frequency meter, which operates on the phenomenon of electrical resonance, is very simple in construction and is shown.

It consists of a laminated iron core of varying cross-section, a fixed magnetizing coil mounted at one end of the iron core and a moving coil with a pointer attached to it and pivoted so that it can move freely over the iron core. The moving coil is connected across a suitable capacitor “C” and the fixed coil is connected across the supply circuit, whose frequency is to be measured. When the magnetising coil is connected across the supply circuit, current “I” flows through it and a flux 4 in phase with current I is set up in the iron core and an e.m.f. “e” lagging behind the flux 4i by 900 is induced in the moving coil. The current in the moving coil will be lagging or leading the induced e.m.f. “e”, depending.