Abstract: An electronic watthour meter is digitally configurable to operate as several different types of watthour meters for metering electrical energy from a variety of different electric utility services. Automatic scaling of line input currents is provided to scale the voltage input to an analog to digital converter over selected ranges such that low level and high level input signals are measured in an optimum range. A digital signal processor is employed to calculate values for metered electrical energy and output pulses, each proportional to a quantum of energy flowing in the circuit being metered. The processor calculates the value of DC offset errors inherent in the various analog circuits of the meter and uses that value in the calculation of metered electrical energy to compensate for such offset errors. The meter employs automatic and manually initiated test functions for testing the operation of the processor and other critical circuits in the meter.

Abstract: An electronic watthour meter is digitally configurable to operate as several different types of watthour meters for metering electrical energy from a variety of different electric utility services. Automatic scaling of line input currents is provided to scale the voltage input to an analog to digital converter over selected ranges such that low level and high level input signals are measured in an optimum range. A digital signal processor is employed to calculate values for metered electrical energy and output pulses, each proportional to a quantum of energy flowing in the circuit being metered. The processor calculates the value of DC offset errors inherent in the various analog circuits of the meter and uses that value in the calculation of metered electrical energy to compensate for such offset errors. The meter employs automatic and manually initiated test functions for testing the operation of the processor and other critical circuits in the meter.

Abstract: A phoneme-based speech synthesizer that is particularly adapted for implementation on a single integrated circuit chip. The vocal tract is comprised of a fixed resonant filter and a plurality of tunable resonant filters whose resonant frequencies are controlled in accordance with the values of certain control parameters. The vocal tract is implemented utilizing a capacitive switching technique which eliminates the need for large valued components to achieve the relatively low frequencies of human speech. In addition, a novel digital transition circuit is included which gradually transitions the values of the vocal tract control parameters as they change from phoneme to phoneme. A unique glottal source generator is also disclosed which is adapted to digitally generate a glottal pulse signal in a manner which readily permits the glottal pulse to be spectrally shaped in any desired configuration.