Abstract: A system for monitoring use of a utility at a consumer's premises is disclosed. The system may include monitoring apparatus to detect use of the utility, a first register to store an indicator signal indicating whether or not use of the utility at the consumer's premises is authorized, and an unauthorized use signal generator, responsive to the monitoring apparatus output and the contents of the register, to generate an unauthorized use signal when the monitoring apparatus output indicates use of the utility and the first register contains an indicator signal indicating that use is not authorized.

Abstract: DC offset is measured by separating the positive and negative half cycles of the AC waveform, obtaining a measure of the energy content of each type of half cycle and subtracting one from the other and accumulating the result. The accumulated result is measured against a threshold which is selected to have a known relationship to the units used to measure the DC offset. Each time the threshold is exceeded, this increments a counter and at the same time resets the accumulator. The contents of the counter can then be multiplied by an appropriate scaling factor. The square root of this result gives a measure of DC offset.