Nec Corporation

The Tokyo Electric Power Company, Incorporated

Nec Corporation and the Tokyo Electric Power Company, Incorporated

Masatoshi Komatsu

Tadashi Kobayashi

Toshio Takagi

Hidetake Nakamura

Shigeo Fushimi

Shigenori Wada

A transmission and reception system includes a transmitting unit and a receiving unit. The transmitting unit transmits a transmission signal including at least a data signal and a clock signal. The data signal is transmitted at a random timing. The receiving unit includes a delay unit for delaying the data signal by a predetermined time period in synchronous with the clock signal. A buffer unit operates in synchronous with the clock signal, temporally stores the data of the delayed data signal and outputs the data. A control units operates in synchronous with the clock signal, controls the storing and outputting operations of the buffer unit. A reset unit operates in synchronous with the clock signal, supplies a reset signal at start timing of the data signal to reset the control unit.

Receiving circuit reset upon reception of burst data and

In a watt-hour meter in which first and second input signals representing an analog electric current and an analog voltage of an alternating current are converted into first and second digital signals, a first adder produces a sum signal which represents a sum of the first input signal and an additional analog signal of a frequency different from that of the first input signal and which is substituted for the first input signal. The meter may further comprise a second adder which adds another additional analog signal to the second input signal. Alternatively, the meter comprises low-pass filters and oversample-and-convert circuits to produce the first and the second input digital signals.

Meter for accurately measuring integrated electric power

In a watt-hour meter in which first and second input signals representing an analog electric current and an analog voltage of an alternating current are converted into first and second digital signals, a first adder produces a sum signal which represents a sum of the first input signal and an additional analog signal of a frequency different from that of the first input signal and which is substituted for the first input signal. The meter may further comprise a second adder which adds another additional analog signal to the second input signal. Alternatively, the meter comprises low-pass filters and oversample-and-convert circuits to produce the first and the second input digital signals. As a further alternative, the meter comprises a first inverter for inverting a selected one of the first and the second input signals into a first inverted signal. In this event, a first selector alternatingly selects one of the first inverted signal and the selected one of the first and the second input signals and the other of the first inverted signal and the selected one of the first and the second input signals at a predetermined time interval as a first selected signal. A second inverter for inverting a product signal representing a product of the first and the second digital signals into a second inverted signal. Ganged with the first selector, a second selector alternatingly selects one of the second inverted signal and the product signal at the predetermined time interval as a second selected signal so that the second inverted signal is selected when the first selector selects the first inverted signal.

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Tokyo, Japan

Masatoshi Komatsu