JPH0414751B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a watt-hour meter, and more particularly to a switch that automatically connects and disconnects electrically between a voltage circuit and a current circuit. It is.

[Prior Art] FIG. 9 shows a terminal portion of a conventional watt-hour meter disclosed in, for example, Japanese Utility Model Application Publication No. 179378/1983. In the figure, 1 is the base of the electricity meter, 2 is a terminal block attached to a predetermined location on this base 1, and this terminal block 2 includes a power supply terminal part 3, a load terminal part 4, and a power meter. Terminal section 5 for input/output to the internal circuit of the meter, terminal section 6 for voltage input
Furthermore, a test terminal section 7 for electrical connection and disconnection between the voltage circuit and current circuit of the watt-hour meter is provided.

The test terminal section 7 is shown in FIGS. 10 to 13.
As shown in the figure, an actual load terminal screw 8 and a test terminal screw 9 are respectively inserted into the holes 2a and 2b of the terminal block 2 with a predetermined pitch dimension L, and furthermore, each of the holes 2a , 2b are screwed into the screw holes of the power supply terminal piece 3a and the voltage input terminal piece 6a, respectively, which are arranged on the lower side of the terminal pieces 3a and 2b.
Reference numeral 10 denotes a slide piece used for electrical connection and disconnection between the terminal screws 8 and 9, that is, connection and disconnection of the voltage circuit and the current circuit, and has a semicircular arc-shaped notch 10a on its tip side. Further, elongated holes 10b are formed on the body side, and the test terminal screw 9 inserted into the hole 2b through the elongated holes 10b is used as a guide to move in the left-right direction.

Next, the operation of the conventional watt-hour meter having the above configuration will be explained. First, when adjusting the measurement error of the electricity meter and verifying the error, move the slide piece 10 to the right to electrically separate the terminal screws 8 and 9 as shown in FIGS. 10 and 11. This opens the voltage circuit and current circuit. At this time, the insulation distance l between the actual load terminal screw 8 and the tip of the slide piece must be a value necessary for insulation protection of the imaginary load test device used when adjusting measurement errors. On the other hand, the pitch dimension L
is regulated by the dimensions of an auto-connector that is electrically connected to an imaginary load testing device used for adjusting measurement errors, etc., and it is difficult to increase the insulation distance l.

Next, when using the actual load, use the terminal screw 8 for the actual load.
After loosening the test terminal screw 9 and moving the slide piece 10 to the left, tighten both terminal screws 8 and 9 to connect the terminal screws 8 and 9 with electricity as shown in FIGS. 12 and 13. Connect the voltage circuit and current circuit by connecting the

Incidentally, adjustment, testing, and verification of measurement errors of watt-hour meters are generally performed by an imaginary load test method. The imaginary load test method is a method in which the voltage and current applied to the watt-hour meter are supplied from separate power sources.Compared to the actual load test method, the power supply equipment requires a small capacity, and the voltage, current, and their phase angles are There is the advantage that adjustments can be made without interference.

When performing adjustment or testing using the imaginary load test method, it is necessary to electrically open the voltage circuit and current circuit of the watt-hour meter. On the other hand, when actually using a watt-hour meter, measurement cannot be performed unless the voltage circuit and current circuit are connected.

[Problems to be Solved by the Invention] Since the test terminal portion of the conventional watt-hour meter is configured as described above, both terminal screws 8 and 9 must be loosened in order to use the meter under actual load. Slide piece 10
Not only is it inconvenient to have to move the terminal screws 8 and 9 and then tighten the terminal screws 8 and 9 after making an electrical connection between both terminal screws, but it also causes problems such as loosening over time or forgetting to tighten them. There were also concerns. Furthermore, during an imaginary load test, it has been difficult to ensure sufficient insulation protection for the watt-hour meter body and the imaginary load test device, since the l dimension (insulation distance) cannot be sufficiently secured.

The present invention has been made to solve the above-mentioned problems, and it eliminates the need to move the slide piece in order to use it under actual load, and also eliminates the worry of loosening over time or forgetting to tighten it. It is an object of the present invention to provide a watt-hour meter that is free from noise and can provide sufficient insulation protection for the watt-hour meter itself and an imaginary load test device during adjustment and testing.

[Means for solving the problems] In order to achieve the above-mentioned object, the present invention includes the following steps:
A terminal section for connecting to the circuit under test, and a terminal section that is separably connected to this terminal section via a terminal that can be freely connected and detached, detects the load voltage and load current level of the circuit under test, and displays the detection results by counting. In addition, the element section is provided with a switch for electrically connecting and disconnecting the voltage circuit and the current circuit, and the terminal section is provided with an opposing switch when the element section and the terminal section are coupled. It is characterized by the provision of a magnet that applies magnetic force to the switch to control the turning on of the switch.

[Function] In the present invention, when the element part and the terminal part are connected, the switch for connecting and opening the voltage circuit and the current circuit can be automatically closed for use with an actual load, and the element part and the terminal part can be connected. In the separated state, the switch can be opened and subjected to an imaginary load test.

[Embodiment] Hereinafter, one embodiment of FIGS. 1 to 3 in which the present invention is applied to an electronic watt-hour meter will be described.
In the figure, 3 is a power supply terminal part, 4 is a load terminal part, and holders 11a, 11b, 11, respectively.
c, and these power supply terminal portion 3, load terminal portion 4, and each receiving plate 11a, 11
b, 11c are housed in the base 1, and the terminal part 1
2.

Moreover, each of the above-mentioned receivers 11a, 11b, 11c has plug terminals 13a, 13 as shown in FIG.
b, 13c are inserted, and each of these plug terminals 1
3a, 13b, and 13c are connected to the primary sides of the current transformer 14, voltage transformer 15, and power transformer 16. The secondary outputs of the current transformer 14 and voltage transformer 15 are sent to a power pulse train converter 17, and the secondary outputs of the power transformer 16 are sent to a stabilized power supply device 18.
Further, the output of the stabilized power supply device 18 is inputted to a power pulse train converter 17 and a count display circuit 19, respectively. The count display circuit 19 also includes the power pulse train converter 1.
7 output is input. The above-mentioned plug terminals 13a, 13b, 13c, current transformer 14, voltage transformer 15, power transformer 16, power pulse train converter 17, stabilized power supply device 18, and count display circuit 19 are housed in the cover 20, The element section 21 is configured.

FIG. 4 is a block diagram showing another embodiment in which the present invention is applied to an inductive watt-hour meter. Each plug terminal 13
a, 13b, and 13c are connected to a current coil 22 and a voltage coil 23. Although not shown in the figure, inside the cover is a rotor that is rotated by the interaction of magnetic fluxes generated by two drive elements, each of which includes the current coil 22 and voltage coil 23, and its rotation speed. A metric display device that integrates and displays the information is housed therein, and constitutes the element section 21.

Next, to explain the main parts of each of the above embodiments with reference to FIG. A permanent magnet 25 is provided on the front side of the terminal portion 12 housed in the base 1 at a position facing the switch 24. The switch 24 is a reed switch whose opening and closing are controlled by a permanent magnet or an electromagnet.

Therefore, as shown in FIGS. 2 and 3,
When the cover 20 housing the element section 21 and the base 1 housing the terminal section 12 are connected in the same manner as in a conventional meter, the magnetic force of the permanent magnet 25 causes the switch 2 to
4 are automatically closed, the voltage circuit and current circuit of the watt-hour meter are electrically connected, and this can be used for actual load.
When the circuits 2 and 2 are separated, the switch 24 is automatically opened to electrically open the voltage circuit and the current circuit, making it possible to perform an imaginary load test on the element section 21.

As described above, the electricity meter of the present invention has an element section 2
1 and the terminal section 12 can be separated into the cover 20 side and the base 1 side, so only the element section 21 can be used during measurement error adjustment and testing, and it is not necessary to perform it in combination with the terminal section 12. There isn't. Therefore, it is sufficient to adjust and test the measurement error of the watt-hour meter only on the element part 21, and in this case, the test terminal part (not shown), which is the terminal part 12 except for the permanent magnet 25, and the element part 21 are used. If this is done in combination, the switch 24 will not close and the voltage circuit and current circuit can be kept electrically open, making it possible to perform an imaginary load test.

Furthermore, when the watt-hour meter is actually used, the switch 24 can be closed by combining the element section 21 and the terminal section 12, and the voltage circuit and the current circuit can be electrically connected. Since the connection state can be maintained, the power meter can measure the amount of power used by the circuit under test.

Note that in order to ensure a high degree of insulation between the voltage circuit and the current circuit during adjustment or testing, a switch with a high withstand voltage value may be used.

[Effects of the Invention] As described above, according to the present invention, in the element part,
A switch is provided for electrically connecting and disconnecting between the voltage circuit and the current circuit, and the terminal section is provided with a magnet that controls the turning on of the switch by applying the magnetic force of the opposing switch when the element section and the terminal section are coupled. established,
Since the switch is configured so that it automatically closes only by connecting the element part and the terminal part,
This saves you the trouble of moving the slide piece to close the voltage circuit and current circuit when using the actual load, and there is no need to worry about the connections between the voltage circuit and current circuit becoming loose over time or forgetting to tighten them. Furthermore, there is an effect that the insulation protection of the watt-hour meter body and the imaginary load test device can be significantly improved during the imaginary load test.

[Brief explanation of drawings]

Figures 1 to 3 all show one embodiment of the present invention, with Figure 1 being a block diagram showing the circuit configuration, Figure 2 being a front view of the watt-hour meter, and Figure 3 being the watt-hour meter. 4 is a block diagram showing the circuit configuration of another embodiment of the present invention, FIG. 5 is a side view showing a cover in which the element section according to the present invention is housed, and FIG. FIG. 7 is a front view showing the terminal portion according to the present invention, FIG. 8 is a side view of the device shown in FIG. 7, and FIGS. 9 to 13 all show conventional watt-hour meters. FIG. 9 is a front view showing the terminal part, FIGS. 10 and 11 are front views and cross-sectional views of the test terminal part showing enlarged portion A in FIG. 9, and FIGS. 12 and 13 respectively. Each figure is the first
12 is a front view and a cross-sectional view showing the state when the slide piece is moved to the left from the position shown in FIGS. 0 and 11. FIG. In the figure, 11a, 11b, 11c are receivers, 12 is a terminal part, 13a, 13b, 13c are plug terminals, 21 is an element part, 24 is a switch, 25
is a permanent magnet. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Claims] 1 A terminal section for connecting to the circuit under test, and a terminal section that is separably coupled to this terminal section via a terminal that can be freely connected and detached to detect the load voltage and load current level of the circuit under test and count the detection results. In the watthour meter equipped with an element section for display, the element section includes:
A switch is provided to electrically connect and disconnect between the voltage circuit and the current circuit, and the terminal section includes a magnet that applies magnetic force to the opposing switch to control the switching on and off when the element section and the terminal section are coupled. A power meter characterized by being provided with.