JP3068958B2 - Electronic watt-hour meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic watt-hour meter.

[0002]

2. Description of the Related Art A conventional electronic watt-hour meter operates as follows.

That is, the multiplier multiplies a first voltage signal proportional to the load voltage from the auxiliary transformer by a second voltage signal proportional to the load current from the auxiliary current transformer to output a power signal. . The power-to-frequency converter converts the power signal into a frequency pulse signal, and the frequency divider further divides the pulse signal.

The arithmetic unit integrates the pulse signal proportional to the power from the frequency divider to calculate a pulse signal proportional to the power amount. Since the pulse signal from the arithmetic unit is parallel data, the parallel / serial converter converts it into serial data that can be output to the outside.

A pulse signal proportional to the power from the frequency divider,
The pulse signal proportional to the electric energy from the parallel / serial converter is output to the outside via the measuring pulse output device and the electric energy data output device, respectively.

[0006]

In such a conventional electronic watt-hour meter, it is necessary to provide an electric energy data output device to output electric energy data to the outside, so that the electric power meter becomes large and expensive. I have. An object of the present invention is to provide a small and low-cost electronic watt-hour meter.

[0007]

In order to achieve the above object, a first aspect of the present invention is a first aspect of the present invention, wherein a first voltage proportional to a load voltage of a power supply line is provided.
Frequency dividing means for dividing a pulse signal having a frequency corresponding to the power signal obtained from the voltage signal of the power supply line and the second voltage signal proportional to the load current of the power supply line into a predetermined pulse signal; Calculating means for calculating the amount of power from the pulse signal; converting means for converting parallel data of the pulse signal corresponding to the amount of power from the calculating means into serial data; output signals from the converting means and pulse signals from the frequency dividing means And a weighing pulse output means for outputting an output signal from the switching means to the outside.

According to a second aspect of the present invention, there is provided a power supply line having a frequency corresponding to a power signal obtained from a first voltage signal proportional to a load voltage of the power supply line and a second voltage signal proportional to a load current of the power supply line. Frequency dividing means for dividing the pulse signal into a predetermined pulse signal; calculating means for calculating the amount of power based on the pulse signal from the frequency dividing means; and parallel data of the pulse signal corresponding to the amount of power from the calculating means for serial data Conversion means for converting to
Control means for controlling the outputs of the frequency dividing means and the converting means based on the signal from the frequency dividing means; and a measuring pulse output means for outputting a power signal and a pulse signal corresponding to the power amount output controlled by the control means to the outside The gist consists of the following.

[0009]

According to the first aspect of the present invention, the switching means selects and outputs a pulse signal corresponding to the power output from the frequency dividing means and a pulse signal corresponding to the amount of power output from the converting means. Since the measuring pulse output means outputs the respective pulse signals output from the switching means to the outside, an output device for the electric energy data is not required.

Further, in the second invention, the control means converts the pulse signal corresponding to the power from the frequency dividing means and the pulse signal corresponding to the amount of power from the converting means with the control signal based on the output signal of the frequency dividing means. Since the output is controlled and the measuring pulse output means outputs the respective output signals from the control means to the outside, an output device for the electric energy data becomes unnecessary.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram of an electronic watt-hour meter according to one embodiment of the present invention.

In FIG. 1, when a pulse signal proportional to the power obtained from a preceding device (not shown) is input to a frequency divider 1, the pulse signal is divided and output. The arithmetic unit 2 performs an integration operation using the pulse signal from the frequency divider 1 to calculate the electric energy. The obtained data of the electric energy is supplied to the electric energy indicator 3 and the parallel / serial converter 4. The power amount display 3 displays the power amount according to the input data.

The parallel / serial converter 4 converts the input parallel data into serial data, adds appropriate data, and outputs a pulse signal. The signal changeover switch 5 selects and outputs a pulse signal output from the frequency divider 1 and a pulse signal output from the parallel / serial converter 4. The measuring pulse output device 6 converts the pulse signal from the signal changeover switch 5 into a no-voltage contact pulse or a light pulse signal, whereby the instantaneous power and the power amount can be confirmed from outside the electronic wattmeter. 2 and 3 show another embodiment of the present invention.

In FIG. 2, a pulse signal output from the frequency divider 1 is input to the timing control device 7. This pulse signal is shown in (a) of the timing chart of FIG. The timing control device 7 supplies the control signal according to the pulse signal (a) to the signal changeover switch 5 directly or by inverting the control signal with the inverter 8. The control signal output from the timing control device 7 is shown in FIG. The control signal inverted by the inverter 8 is output to the parallel / serial converter 4.
To control the timing of starting parallel / serial conversion. The pulse signal output from the parallel / serial converter controlled in this way is shown in FIG. By the above method, the pulse signal output from the frequency divider 1 and the pulse signal output from the parallel / serial converter 4 are combined and output from the signal changeover switch 5. The signal output from the signal changeover switch 5 is shown in FIG. The measuring pulse output device 6
The input pulse signal is converted into a no-voltage contact pulse or a light pulse signal, whereby the instantaneous power and the power amount can be confirmed from outside the electronic wattmeter.

[0015]

As described above, according to the first and second aspects of the present invention, the switching means switches between the pulse signal corresponding to the power from the frequency dividing means and the pulse signal corresponding to the amount of power from the converting means. And the output is controlled by the output or control means, and the weighing pulse output means outputs the respective signals from the switching means or the control means to the outside. A low-cost electronic wattmeter can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of an electronic watt-hour meter of the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the electronic watt-hour meter of the present invention.

FIG. 3 is a waveform chart for explaining the operation of FIG. 2;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... frequency divider, 2 ... arithmetic unit, 4 ... parallel / serial converter, 5
... Signal changeover switch 6 ... Measurement pulse output device, 7 ... Timing control device

Claims (2)

(57) [Claims] 1. A pulse signal having a frequency corresponding to a power signal obtained from a first voltage signal proportional to a load voltage of a power supply line and a second voltage signal proportional to a load current of the power supply line is predetermined. Frequency dividing means for dividing the pulse signal into a pulse signal, an arithmetic means for calculating an electric energy based on the pulse signal from the frequency dividing means, and converting parallel data of the pulse signal according to the electric energy from the arithmetic means into serial data Converting means for selecting one of an output signal from the converting means and a pulse signal from the frequency dividing means, and a measuring pulse output for outputting the output signal from the switching means to the outside. Electronic watt-hour meter having means. 2. A pulse signal having a frequency corresponding to a power signal obtained from a first voltage signal proportional to a load voltage of a power supply line and a second voltage signal proportional to a load current of the power supply line is predetermined. Frequency dividing means for dividing the pulse signal into a pulse signal, an arithmetic means for calculating an electric energy based on the pulse signal from the frequency dividing means, and converting parallel data of the pulse signal according to the electric energy from the arithmetic means into serial data Converting means, control means for controlling outputs of the frequency dividing means and the converting means based on a signal from the frequency dividing means, and a power signal output controlled by the control means and a pulse signal corresponding to a power amount. Electronic watt-hour meter having a weighing pulse output means for outputting a signal to the outside.