Patent ID: 11860198
Assignee: SENTEC LTD
Field: Measurement (Instruments)
Classification: CPC G | IPC G  H

Claim 12:
13. Apparatus for processing signals received from a mutual inductance current sensor having a first transfer function, the apparatus comprising:
a low-pass filter which receives a signal from the current sensor, the low-pass filter having a second transfer function configured to attenuate one or more harmonic components of the signal;
an analogue-to-digital converter which receives and digitises a filtered signal output from the low-pass filter;
a controller configured to process a digitised current signal from the analogue-to-digital converter using a digital processing chain configured to compensate for the frequency and phase responses of the first transfer function and the second transfer function;
wherein the apparatus is for measuring a signal corresponding to an alternating current having a fundamental frequency and wherein the apparatus is configured to measure up to a predetermined harmonic of the fundamental frequency;
wherein the second transfer function of the low-pass filter has a −3 dB corner frequency which lies between the fundamental frequency and the predetermined harmonic.