Electrodynamics Instrument Wattmeter •Two Magnetic Field Coils • Usualy has air damping • No iron core, flux path is entirely air • Moving coil current is much larger than PMMC • TD α Ifc x Imc 2 • TD α I
Electrodynamics Instrument Wattmeter •Two Magnetic Field Coils • Usualy has air damping • No iron core, flux path is entirely air • Moving coil current is much larger than PMMC • TD α Ifc x Imc 2 • TD α I