| 摘要 |
Measuring a DC or a low frequency AC current by feeding the current to be measured through the primary winding of a transformer, whereby a first flux is generated in the transformer and generating a modulating voltage and also phase shifting the modulating voltage. The phase shifted modulated voltage is applied across the secondary winding of the transformer with an amplitude so as to saturate the core. The phase difference between the modulating voltage and the phase shifted modulating voltage is monitored while feeding a compensating current of increasing amplitude through the secondary winding until the phase difference is zero. The amplitude of the compensating current at zero phase difference is a representation of the current to be measured. |
