JP2000241465A - Simplified electric energy indicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure and know easily a standard of power consumptions of individual electric apparatuses even in a general home with a simple using method, and to compose the whole in a small size and inexpensively. SOLUTION: This indicator is so composed that an alternating current measured by an alternating-current machine 11 is converted into a direct current by a rectifier circuit 12, and that the direct current is compared with a direct current obtained by averaging pulse width modulation signals having variable duty ratios through a low-pass filter 13, to calculate an electric energy by a controller 15 composed of a one-chip microcomputer at the timing when both agree with each other, and that the calculated electric energy, power rates and an integrated current-sending time are displayed cyclically on an LCD indicator 4 in a preset order and in a preset time interval.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an electric power consumption including standby electric power of various electric appliances owned by a general household or an electric power consumption of an electric equipment installed in a factory or an office. The present invention also relates to a simplified power amount indicator used to obtain a guide such as a power rate according to the power consumption.

[0002]

2. Description of the Related Art Televisions owned by modern households,
As a means of knowing the power consumption of a plurality of electric appliances such as a refrigerator and a washing machine or a plurality of electric facilities installed in factories and the like, the power consumption of the plurality of electric appliances and electric facilities (hereinafter referred to as electric appliances) is used. In general, means for reading the numerical value displayed on a large integrated watt-hour meter installed for each power consumer is the total integrated power amount obtained by integrating the total power amounts.

In addition, as a means for knowing the amount of power consumption of each electric device, current and voltage are simultaneously measured using a tester, and the energizing time is measured with a clock.
Means of calculating an integrated electric energy by multiplying the two and then multiplying the integrated electric energy by a unit price of charge to calculate a total electric charge is also considered.

[0004]

However, in the case of means for reading a numerical value displayed on a large-scale integrated watt-hour meter as in the former case, it is only possible to know the total integrated power amount of a plurality of electric devices. Know the amount of power required for each electrical device and the electricity rate required by multiplying the unit price by the unit price of electricity, which is important for promoting energy saving measures at homes and energy saving measures at factories, etc. There is a problem that can not be.

In the latter case, although it is possible to know the electric energy of each electric device, a tester is required to measure current and voltage at the same time. It requires a high level of technical knowledge and skill to use. In addition, it is not enough to measure current and voltage alone, multiply the measured value by the energization time to calculate the integrated energization amount. Very complicated calculations, such as multiplying to calculate the total electricity charge, are also necessary, and there is a problem that it cannot be easily put to practical use especially in ordinary households, in view of economy and usage of the equipment.

[0006] The present invention has been made in view of the above circumstances, is easy to use, can easily measure and know the standard of the power consumption of each electric device even in a general household, and very much as a whole. It is an object of the present invention to provide a simple electric power indicator that can be configured to be small and inexpensive.

[0007]

In order to achieve the above object, a simplified electric energy indicator according to the present invention comprises a current transformer for measuring an AC current and an AC current measured by the current transformer. A rectifier circuit for converting to a DC voltage, a comparator for comparing the output from the rectifier circuit with an output from a low-pass filter for averaging the pulse width modulation signal to a DC voltage, and an output terminal of the comparator. A controller that is connected to change the pulse width duty ratio of the modulation signal until the output from the comparator is inverted, and that quantifies the pulse width duty ratio at that time to calculate a power amount, and a controller that calculates the power amount. A display for displaying the amount of electric power.

According to the present invention having the above configuration, an AC current measured using a current transformer is converted into a DC voltage by a rectifier circuit, and the DC voltage and a pulse width modulation signal having a variable duty ratio are low. By comparing the DC voltage averaged by the bandpass filter with the comparator and calculating the electric energy at the timing when the two coincide with each other, the pulse width modulation and the electric energy calculation which are complicated digital conversion means can be performed. Only the controller to be used can be constituted by a one-chip microcomputer, and the rest can be constituted by combining a current transformer and a simple analog rectifier circuit for converting an alternating current measured by the current transformer into a direct current. As a result, the circuit configuration of the entire electric energy display becomes simple, compact and inexpensive, and it is possible to measure and know the standard of electric energy of each electric device arbitrarily, and its usage is very simple and general. It can be easily used at home.

[0009] In the above-mentioned simplified electric energy display, the rectifier circuit is composed of a combination of an operational amplifier and a rectifier diode, and the rectifier circuit has a linearity suppressing circuit for expanding a measurement range. Is attached, it becomes possible to measure a minute amount of electric power such as standby electric power of an electric appliance, and the measuring range of the electric energy can be expanded.

[0010] In the above-described simplified power display,
As described in claim 3, the control unit has means for calculating the electricity amount and the electricity amount obtained by multiplying the electricity amount by the unit price, and measuring the accumulated energization time. By configuring so that the energization time is switched and displayed in a predetermined order on the display, and at set time intervals, not only the amount of power but also the electricity rate and the accumulated energization time related thereto are displayed. By accurately grasping the power usage status of each electric device, it can greatly contribute to energy saving measures in ordinary households and energy saving measures in factories and the like.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing the appearance of a simplified electric energy display according to a first embodiment of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a bottom view thereof. As shown in FIGS. 1 to 3, for example, a substantially box-shaped device case 1 including a case main body 1A and a lid cover 1B molded from a thermosetting resin such as a noril resin has a rear portion of the case main body 1A. Outlet fixed on the wall etc. (not shown)
A plug 3 is provided on the bottom of the case body 1A, and an outlet 3 is provided on the bottom of the case body 1A.

Further, a rectangular opening 1a is formed in the surface of the lid cover 1B of the device case 1, and the opening 1a
a, a single LCD (liquid crystal) display 4 is fixedly held. As shown in FIG. 4, the LCD display 4 has a three-digit numerical display section 4A in which seven segments are arranged in a figure-eight shape.
In the operation display section 4B and the numerical display section 4A in which the dot blinks on the left side of the most significant digit, the unit symbols “Yen” and “kW” corresponding to a plurality of display items described later are displayed on the right side of the least significant digit.
It has a unit symbol display section 4C for displaying "h" and "time".

On the other hand, in the equipment case 1, there is provided an arithmetic circuit (arithmetic means) 10 as follows for calculating the integrated energizing time, the amount of electric power and the electric charge. As shown in FIG. 5, the arithmetic circuit 10 includes a current transformer (CT) 11 for measuring an AC current I input from the device plug 2 and an AC current measured by the AC device 11 through a resistor R1. A rectifier circuit 12 for converting the AC voltage into an AC voltage and converting the AC voltage into a DC voltage; a pulse voltage having an output terminal connected to one input terminal and a pulse width modulated at the other input terminal; Low-pass filter 13 for averaging the current to a DC current
And the comparator 1 to which the output terminal of the comparator 1 is connected.
4 is connected to the output terminal of the device plug 2 to calculate the amount of electric power and the electric charge obtained by multiplying the amount of electric power by the unit price.
And a controller 15 that counts the cumulative power-on time from the point of time when the power supply is plugged into the outlet. The power amount and the electricity rate calculated by the controller 15 and the counted cumulative power-on time are counted by the LCD display 4. It is configured to be output to.

The specific configuration of the arithmetic circuit 10 will be described together with the operation.
Is divided by resistors R1 and R2, and the AC current flowing into one resistor R2 is amplified by a feedback resistor R3 connected to an operational amplifier OP, and at the same time, a diode D
The half-wave rectification is performed by 1 and D2. After the pulsating component of the half-wave rectified voltage is removed by the capacitor C 1, the DC voltage V 1 is input to one input terminal of the comparator 14. On the other hand, the pulse width modulation signal V2 output from the controller 15 is input to the low-pass filter 13 while being changed so that the pulse width duty ratio gradually increases from 0%, where the resistor R5 and the capacitor C2 , A DC voltage V3 proportional to the pulse width duty ratio is generated, and this DC voltage V3 is input to the other input terminal of the comparator 14.

The comparator 14, to which the DC voltages V1 and V3 have been input, goes to a high level when V3≥V1 and outputs an output V4.
The power value W is calculated by multiplying the value of the pulse width duty ratio of the modulation signal V2 at the point of time when the power is inputted by the proportional constant K. _{That, W = T 0N / (T} ON + T OFF) × K T ON: high level time of V2, T _OFF: V2 low level time

The above operation is repeated at regular time intervals τ, and the number of times of sampling (elapsed time) is T,
The power amount Wh is calculated by the following equation (1), and the calculated power amount Wh is added to the unit price {for example, 25 yen / kWh (fixed)}.
Is multiplied to calculate the electricity rate.

[0017]

[Formula 1]

In the arithmetic circuit 10 as described above, only a controller 15 for performing pulse width modulation and power amount calculation as complicated digital conversion means is constituted by a one-chip microcomputer.
Otherwise, the current transformer 11 and a simple analog rectifier circuit 12 for converting an AC current measured by the current transformer 11 into a direct current may be combined. Cost and cost can be reduced.

The electric energy, the electricity bill, and the accumulated energizing time calculated by the arithmetic circuit 10 are stored in the control unit 1.
5, the numerical value display section 4A of the LCD display 4 in the order of the electric energy, the electricity rate, and the cumulative energizing time, and at intervals of 3 seconds, as shown in FIG. Are displayed cyclically, and at the same time, unit symbols corresponding to each display item are displayed in the unit symbol display section 4C in the order of "yen", "kWh", and "time". In the case where electric power is consumed by the electric device inserted and connected to 3, the operation display section 4B of the LCD display 4 is configured so that dots are blinked at one-second intervals.

Further, by pulling out the device plug 2 from the outlet and plugging it into the outlet again, the display of the LCD display 4 is reset and the measurement display is started from the beginning.

Next, the measurement and display operation of the simple electric energy display constructed as described above will be briefly described with reference to the flowchart of FIG. By plugging and connecting a desired electrical device into the device outlet 3 and then plugging and plugging the device plug 2 into the outlet, the reset function operates and all the displays on the LCD display 4 are reset (steps S21 and S22).

At the same time when the device plug 2 is inserted and connected to the outlet, it is determined whether or not the electric device connected to the device outlet 3 consumes power (step S23). The dots blink on the display unit 4B at one-second intervals (step S24), and the control unit 15 of the arithmetic circuit 10 counts the integrated power-on time, calculates the amount of power, and calculates the amount of electricity according to the amount of power as described above. An arithmetic function such as calculation works (step S25).

The integrated energizing time, the amount of electric power, and the electricity rate calculated by the operation of the arithmetic circuit 10 are output from the control unit 15 to the LCD display 4, and are the numerical value of the amount of electric energy and the corresponding unit symbol. LCD display in the order of "kWh", the numerical value of the electricity rate and the corresponding unit symbol "yen", the numerical value of the integrated energizing time and the corresponding unit symbol "hour", and at a time interval of 3 seconds Vessel 4
Are cyclically displayed on the numerical value display section 4A and the unit symbol display section 4C (steps S26 to S3).
1).

As described above, by reading the amount of electric power, the electric charge, and the cumulative energizing time displayed cyclically, the amount of power consumption of each electric device and the standard of the electric charge corresponding to the electric power consumption can be known, and the electric power consumption of each electric device can be determined. It is possible to grasp the situation accurately. In addition, by displaying a single LCD display 4 cyclically, it is possible to reduce the area occupied by the display 4 while ensuring that the font of the displayed numerical value does not cause misreading or the like. Combined with the simple and compact circuit configuration described above, the overall weight of the power indicator is reduced,
Compactness can be achieved and handling and use can be made very simple.

In the first embodiment described above, the LCD display 4 is designed to cyclically display the three items of the amount of electricity, the electricity charge, and the cumulative energizing time. Alternatively, a configuration may be adopted in which two items such as the amount of power and the cumulative energization time are cyclically displayed.

Also, as in the first embodiment, when the device plug 2 is pulled out of the outlet and re-inserted and connected, a reset function for resetting all displays is provided, so that a special reset button can be installed. It becomes unnecessary, and even if the reset operation is forgotten, the electric energy and the like of each electric device can be accurately measured and displayed. However, a reset button may be provided.

FIG. 8 shows a second embodiment of the present invention. In this second embodiment, a rectifier circuit 12 comprising an operational amplifier OP, diodes D1 and D2 for half-wave rectification, a feedback resistor R3, and a capacitor C1 is combined. The second feedback resistor R4 is connected in parallel with the feedback resistor R3 in
Is connected to a Zener diode ZD and a backflow prevention diode D3 for determining a feedback branch voltage in series with the feedback resistor R4, and a rectification circuit 12 is added with a linearity suppression circuit for expanding a measurement range.

The operation of the rectifier circuit 12 to which the above-described linearity suppressing circuit is added will be described. When the input value of the alternating current flowing from the alternating current device 11 is equal to or less than the Zener diode ZD voltage in the range from the point 0 to the point a in FIG.
No current flows through the feedback resistor R4, and the voltage is amplified only by the feedback resistor R3.
Is AVO = R3 / R2. On the other hand, when the input value is equal to or higher than the point a in FIG. 9 and equal to or higher than the voltage of the Zener diode ZD, a current also flows through the second resistor R4, and the amplification Av1 is given by: Av1 = R3 × R4 / (R3 + R4) , The amplification decreases by the amount of the second feedback resistor R4. As a result, the range of the input value up to the point b is expanded to the point c, and the measurement range is expanded accordingly, so that it is possible to measure even minute power such as standby power in home electric appliances. The correction of linearity accompanying the addition of the linearity suppressing circuit can be solved only by adding a linearizer operation function in the control unit 15.

[0029]

As described above, according to the present invention,
A controller that uses only a current transformer without using a transformer, and requires a simple analog rectifier circuit that converts AC current measured by this current transformer into DC, and complicated digital conversion means such as pulse width modulation and power amount calculation. In combination with the adoption of a single-chip microcomputer, the circuit configuration is simple and small, and the overall power indicator is lighter, smaller, and lower in cost. It is possible to measure and know, and based on it, it is possible to easily promote power saving measures and energy saving measures. Moreover, its use does not require advanced technical knowledge or skill,
Since a very simple usage method is sufficient, there is an effect that it can be easily used even in a general household.

In the case where the configuration as described in claim 2 is adopted, in addition to the above effects, it is also possible to measure a minute amount of electric power such as a standby electric power of an electric appliance, and to set a measuring range of the electric energy. It can be enlarged and the practicality can be further enhanced.

In addition, by adopting the configuration as described in claim 3, not only the amount of electric power but also the electric charge and the accumulated energizing time related thereto are displayed to accurately grasp the electric power usage status of each electric device. In addition, it can greatly contribute to power saving measures in ordinary households and energy saving measures in factories and the like.

[Brief description of the drawings]

FIG. 1 is a front view showing the appearance of a simplified electric energy display according to a first embodiment of the present invention.

FIG. 2 is a side view of the display device.

FIG. 3 is a bottom view of the display.

FIG. 4 is an explanatory diagram of a configuration of a display unit in the display device.

FIG. 5 is a specific configuration diagram of an arithmetic circuit in the display.

FIG. 6 is an explanatory diagram showing an example of specific display contents on the display.

FIG. 7 is a flowchart illustrating a measurement display operation of the display device.

FIG. 8 is a configuration diagram of a main part of an arithmetic circuit in a simplified power amount display according to a second embodiment of the present invention.

FIG. 9 is a graph showing input / output characteristics in the second embodiment.

[Explanation of symbols]

 Reference Signs List 4 Display (LCD display unit) 11 AC device 12 Rectifier circuit 13 Low pass filter 14 Comparator 15 Controller OP Operational amplifier D1, D2 Rectifying diode

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuhiro Nakatani 3-14-40 Senrioka, Settsu-shi, Osaka Toko Seiki Co., Ltd. (72) Inventor Takahiro Ohno 3-14-40 Senrioka, Settsu-shi, Osaka Toko Seiki Co., Ltd.

Claims (3)

[Claims] 1. A current transformer for measuring an AC current, a rectifier circuit for converting the AC current measured by the current transformer to a DC voltage, and an output from the rectifier circuit and a pulse width modulation signal converted to a DC voltage. A comparator for comparing the output from the low-pass filter to be averaged with the output of the comparator for changing the pulse width duty ratio of the modulation signal until the output from the comparator is inverted; And a controller for quantifying the pulse width duty ratio at that time to calculate a power amount, and a display for displaying the calculated power amount. 2. The rectifier circuit according to claim 1, wherein the rectifier circuit comprises a combination of an operational amplifier and a rectifier diode, and the rectifier circuit is provided with a linearity suppressing circuit for expanding a measurement range.
The simple type electric energy indicator according to 1. 3. The control unit has means for calculating the electric energy and the electric energy obtained by multiplying the electric energy by a unit price, and measuring an accumulated energizing time. In a predetermined order on the display, and
3. The simplified electric energy display according to claim 1, wherein the display is configured to be sequentially switched and displayed at set time intervals.