Wattmeter methods of measuring power expended upon condensers and circuits of low power factor

Wattmeter methods of measuring power expended upon condensers and circuits of low power factor

Year: 1905

The resonance and calorimetric methods for measuring the power expended on low power factor circuits-for instance, on condensers or cables on open circuit-are not adapted to general laboratory work. The simple wattmeter also is not suitable, owing to the necessary corrections which have to be made for the power expended on the ampere coil and for the capacity and inductance of the volt circuit. The author devised a large number of null methods of measuring power in 1898, and employed them for measuring low power factors. In some of these methods an auxiliary coil is wound round the ampere coil. The magnetomotive force due to a current A/sub 3/ in t