JPS58137Y2 - electricity meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a watt-hour meter, and particularly to a watt-hour meter that can effectively extract load current with a simple configuration.

FIG. 1 is a block diagram showing the general configuration of a well-known electronic watt-hour meter, in which 1 is a power source, and 2 is a block diagram of the power source 1.
3 is the electronic wattmeter main body, 1 is the load driven by the
．． s, 2s are input terminals connected to the power source 1, 1t,
, '2t is a load connection output terminal connected to the load 2, 4 is a current transformer such as a current transformer interposed between the input terminal 15 and the output terminal 1L, and 1 is a current transformer for detecting the current value. , 5 is a voltage transformer that detects the voltage at the input terminal 15, and 6 is the output of the current transformer 4, that is, a signal proportional to the input current, and the output of the voltage transformer 5, that is, the input. A multiplier that generates a product of signals proportional to the voltage, that is, an electrical signal proportional to the power value; 7 an integrator that converts the output of the multiplier 6 into a frequency proportional to this; 8 an output of the integrator 7; 9 is a display device that displays the counted value of the counter 7, 10 is a power supply device for obtaining power from the input terminal 15.2s, and 11.12 is an input terminal 1s, respectively.
, a conductor connecting the output terminal 1L to the current transformer 4, for example, if this is a current transformer, its primary coil; 13, a short bar connecting the input terminal 28 and the output terminal 2L; 1;
A conductor 4 connects the input terminal 1s to the voltage transformer 5.

In this configuration, the current value detected by the current transformer 4 and the voltage value detected by the voltage transformer 5 are multiplied by the multiplier 6 and converted into an output proportional to the power value.

The output of the multiplier 6 is input to an integrator 7 and converted into a frequency proportional to the power value, but this converted output is counted by a counter 8 to obtain a count value corresponding to the power amount. I can do it.

This count value, ie, the amount of power, is displayed digitally on the display device 9.

Now, the input terminals Is, 2s and the output terminal I shown in FIG.
The configuration of the connecting parts of L, 2L and the current transformer 4 is shown in the plan view of FIG.
26 connects the conductor 11.12 to the input terminal 1s and the output terminal 1.
．． and mounting screws for connecting to the output terminals 1L, 27 is a core used when a current transformer is used as an element constituting the current transformer 4, and 28 is the conductive wire 11.1.
This is a primary coil wound around the core 27 as an extension of the core 27.

Incidentally, a secondary coil (not shown) is wound around the core 27, and the output of the current transformer 4 is performed based on this output.

According to the configuration shown in FIG. 2, in order to connect the conductive wires 11 and 12 led out from the primary coil 28 to the input terminal 15 and the output terminal 1L, the ends thereof are bent (f) and fixed with the mounting screws 26. Therefore, if the conducting wires 11, 12 are formal wires or the like, it is necessary to remove the covering of the contact portion.

For this reason, work efficiency during assembly work is reduced and the number of assembly steps is increased.

On the other hand, the current transformer 4 also requires another member to fix it, increasing the number of assembly steps.

Furthermore, the larger the capacity of this electronic watt-hour meter, the more problems such as contact resistance and processing of the primary conductor become.
This becomes a factor that hinders manufacturing efficiency.

Therefore, the purpose of the present invention is to eliminate the drawbacks of the above-mentioned prior art.
Using a current transformer with a structure that is easy to attach to the current terminal,
Another object of the present invention is to provide an electronic watt-hour meter with excellent assembly efficiency and high reliability by devising a terminal structure.

More specifically, the present invention extends the position of the connecting screw of the current terminal to a position where the current transformer can be fixed, and furthermore, the current transformer has a mounting hole with the same size as the spacing between the connecting screws. By using a feed-through current transformer, there is provided a new electronic watt-hour meter that eliminates the need for removal of the coating, members for fixing the current transformer, contact resistance, etc.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 3 is a plan view showing the structure of the terminal part and the arrangement of the current transformer of a watt-hour meter according to an embodiment of the present invention. 31 and 32 are arms extending from both poles of a through-type conductor for passing the primary current to the current transformer 4; 43 is the end of the arms 31 and 32; This figure shows the mounting holes provided in each section.

As is clear from the drawing, the input terminal 15 and the output terminal 11 extend from the terminal block 25, and the other input terminals 25 and output terminals 2. − is larger than the extension amount of 12.

At each extending end of the input terminal 15 and the output terminal 1L, the arms 31 and 32 are connected to the mounting screws 26 through the holes 43.
It is constant at 1.

According to this configuration, the arm 31 of the primary conductor of the current transformer 4
．． 32 are connected to the input terminals 18 and 18 with mounting screws 26, respectively.
Since it has a configuration in which it is fixed to the output terminal, the input terminal 1S, the arm 31. Current transformer 4, arm 32, output terminal 11.
The two purposes of forming an electric circuit and fixing the current transformer 4 can be achieved at the same time.

By the way, since the input terminal 15 and the output terminal are made of a conductor with sufficient current capacity, such as brass, they have sufficient mechanical strength, so even if they are slightly extended, the current transformer 4 Sufficient strength can be secured for fixing.

Therefore, it is no longer necessary to remove the coating and bend the tip of the conductor on the primary side of the current transformer 4 as in the conventional case, and the arm 31.
Since it is only necessary to drill a tapped hole 43 for mounting at the end of the 32, work efficiency during assembly can be greatly improved.Furthermore, the simple shape makes it easy to introduce automatic assembly. is also easy to deal with.

Further, since no special member is required for mounting and fixing the current transformer 4, the effect of reducing assembly man-hours and the number of parts is significant.

On the other hand, input terminal 15 and arm 31, output terminal 1L and arm 3
Since the second contact is a surface contact, heat generation can be prevented and power consumption can be reduced.

Therefore, it can be used as a large current meter.

In the embodiment shown in FIG. 3, a through-type current transformer is used as an example of the current transformer, but a combination of a Hall element and a magnetic circuit may also be used.

FIG. 4 is a side view A and a plan view B of a current transformer having such a configuration, in which 41 is a magnetic circuit arranged so as to surround the through conductor connecting the arms 31 and 32, and 42 is a magnetic circuit arranged to surround the through conductor connecting the arms 31 and 32; This is an all-element device inserted into a part of the magnetic circuit 41.

Even in such a configuration, the effect obtained is exactly the same, only the method of current transformation is different.

Furthermore, a current transformer having a second secondary winding for error compensation may be used.

FIG. 5 is a side view A and a plan view B of a current transformer having such a configuration, in which 27A and 27B are the first and second iron cores forming the core, and 53A is the first iron core. 2
A first secondary winding is wound around 7A, a second secondary winding 53B is wound around the second iron core 27B, and 55 is an insulator.

Even in this configuration, the effects obtained are exactly the same as in the configuration shown in FIG. 3, except that error compensation of the current transformer output can be performed.

Now, since the polarity, that is, the phase, of the load current is an important factor in measuring the amount of electric power, the polarity must not be mistaken when installing the current transformer.

In order to eliminate such errors, it is effective to mark the current transformer main body or the lead-out arm, etc., to indicate the polarity, and this can facilitate handling during assembly work.

6A and 6B show plan views of current transformers constructed from this viewpoint, and in the figures, 61, 62 are arms 31.
Symbols 32 and 63 indicate the corresponding terminals and the polarity of the current transformer 4, respectively.

Furthermore, the way in which the current terminals and voltage terminals are extended is not limited to the configuration shown in FIG. 3; for example, as shown in the side view of FIG.
It may be configured such that the terminal block 25 extends from the terminal block 25 at a different level with respect to the input terminal 25 and the output terminal 1L, and the arms 31 and 32 led out from the current transformer 4 are fixed to the tip thereof.

In the above embodiment, a single-phase meter has been illustrated, but it goes without saying that the present invention is similarly applicable to a polyphase meter.

As described above, according to the present invention, it is possible to obtain an economical watt-hour meter that has excellent assembly efficiency, high reliability, and is capable of measuring large-capacity watt-hours.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the general configuration of a well-known electronic watt-hour meter, and FIG. 2 is a plan view showing the configuration of each terminal of the watt-hour meter of FIG. 1 and the connection part of the current transformer. FIG. 3 is a plan view showing the structure of the terminal section and the arrangement of the current transformer of a watt-hour meter according to an embodiment of the present invention, and FIGS. 4A and 4B are side views showing other examples of the current transformer. A plan view, FIGS. 5A and B, is a side view showing another example of the current transformer, and a top view, FIGS. 6A and B.
7 is a plan view showing an example of polarity display of a current transformer, and FIG. 7 is a side view showing another example of terminal extension. is, 2s...input terminal, IL, 2L...
...Output terminal, 4...Current transformer, 25...
...Terminal block, 31, 32...Arm.

Claims (1)

[Scope of utility model registration request] A power meter body that is interposed between a power source and a load and calculates electric energy from current and voltage values, a group of terminals provided on the body for purposes other than taking in current values, and a group of terminals for reading current values into the body. a current transformer having a current terminal attached to extend to a position different from the terminal group to take in the current; an arm extending from a primary conductor for current detection; and the arm being attached to the extending end of the current terminal. A power meter characterized by comprising a fixing member for fixing.