Electronic Indicating Instrument

Abstract

To provide an electronic indicating instrument capable of easily confirming and changing settings even when a power receiving and transforming facility is not receiving power. [Solution] An electronic indicating instrument (digital multimeter 10) is attached to a mounting plate 2 of a power receiving and transforming facility. Multimeter 10 has a first portion 11 provided on the front side of mounting plate 2 and having a display unit, a second portion 12 provided on the rear side of first portion 11 and having connection terminals 16a, 16b, 17a to 17c, and a power supply terminal provided on first portion 11.

Description

[Technical field]

[0001] The present invention relates to an electronic indicating instrument to be incorporated in electrical equipment such as substation equipment. [Background technology]

[0002] Medium-sized facilities such as factories and apartment buildings are often provided with substation equipment that receives power at 6600V AC and transforms it to 100V AC or 220V AC using a transformer. The substation equipment is provided with indicating instruments that measure current, voltage, power, reactive power, power factor, phase angle, frequency, and the like. Indicating instruments include mechanical indicating instruments and electronic indicating instruments (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2024-110193 A Summary of the Invention [Problem to be solved by the invention]

[0004] When using an electronic indicating instrument, it is necessary to set the type of electrical quantity to be displayed on the display, the display method pattern, and measurement items (phase line system, voltage input rated value, etc.). Such settings for electronic indicating instruments are usually performed in the factory where the substation equipment is manufactured. In this case, power is supplied to the electronic indicating instrument by connecting the factory power source to the substation equipment.

[0005] On the other hand, after the power receiving and transforming equipment is shipped from the factory and installed at the installation site, it may become necessary to check or change the settings of the electronic indicating instruments. When the power receiving and transforming equipment receives power, power is supplied to the electronic indicating instruments, so it is possible to change the settings of the electronic indicating instruments. However, between the time when the power receiving and transforming equipment is shipped from the factory and when it receives power, it is not possible to supply power to the electronic indicating instruments, so it is not possible to change the settings of the electronic indicating instruments.

[0006] For example, after the substation equipment is installed at the installation site, if the electronic indicating instrument is temporarily removed from the substation equipment and an external power source such as a battery is connected, it is possible to supply power to the electronic indicating instrument. However, since the wiring of the electronic indicating instrument is attached so as to satisfy standards (such as tightening torque) set by regulations, it is practically impossible to reattach the wiring that was once removed from the electronic indicating instrument to the electronic indicating instrument at the installation site so as to satisfy the above standards.

[0007] Therefore, an object of the present invention is to provide an electronic indicating instrument that allows the settings to be easily checked and changed even when electrical equipment such as a substation equipment is not receiving power. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides an electronic indicating instrument that is mounted on a mounting plate of an electrical equipment, An electronic indicating instrument is provided having a first portion provided on the front side of the mounting plate and having a display unit, a second portion provided on the rear side of the first portion and having a connection terminal, and a power supply terminal provided on the first portion.

[0009] In this way, the electronic indicating instrument according to the present invention has a power supply terminal on the first portion disposed on the front side of the mounting plate of the electrical equipment. This allows an operator to easily access the power supply terminal exposed on the front side of the mounting plate even when the electrical equipment is not receiving power, and by supplying power to the electronic indicating instrument from this power supply terminal, the operator can easily check and change the settings of the electronic indicating instrument.

[0010] The power supply terminal can be, for example, a USB terminal. If data communication as well as power supply is possible via this USB terminal, it will be possible to check and change the settings of the electronic indicating instrument simply by connecting an information device (such as a laptop computer or smartphone) to the USB terminal. Effect of the Invention

[0011] As described above, the electronic indicating instrument of the present invention makes it easy to check and change settings even when the electrical equipment, such as a substation or other electrical equipment in which it is installed, is not receiving power. [Brief description of the drawings]

[0012] [Figure 1] FIG. [Diagram 2] 1 is a front view of an electronic indicating instrument (digital multimeter) according to an embodiment of the present invention; [Diagram 3] FIG. 2 is a side view of the electronic indicating instrument. [Figure 4] FIG. 2 is a rear view of the electronic indicating instrument. [Diagram 5] FIG. 2 is a bottom view of the electronic indicating instrument. [Figure 6] FIG. 2 is a power supply circuit diagram of the electronic indicating instrument. [Figure 7] 4 is a diagram showing a power supply path and a data communication path when the power receiving and transforming equipment receives power. FIG. [Figure 8] 11 is a diagram showing a power supply path and a data communication path when an external power source is connected to the power supply terminal of the electronic indicating instrument. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] Figure 1 shows a cubicle-type high-voltage substation facility, which is a type of electrical equipment. This substation facility has a housing 1 and a switchboard and a switchboard (not shown) housed inside the housing 1. In the illustrated example, the front panel of the housing 1 (the panel on the near side in Figure 1) is an openable and closable door 1a.

[0015] A digital multimeter 10 (hereinafter simply referred to as "multimeter 10") as an electronic indicating instrument according to one embodiment of the present invention is provided in the power receiving board or distribution board housed inside the housing 1 (see Figs. 2 to 5). The digital multimeter is an electronic indicating instrument that integrates the functions of an indicating instrument and a converter.

[0016] Multimeter 10 has a display unit 13 (see FIG. 2). An operator can check values ​​and the like displayed on display unit 13 of multimeter 10 through window 1b (see FIG. 1) provided in door 1a of housing 1 or by opening door 1a of housing 1. In the description of multimeter 10, the side of display unit 13 (left side in FIG. 3) in the direction perpendicular to display unit 13 will be referred to as the "front side," and the opposite side (right side in FIG. 3) will be referred to as the "rear side."

[0017] The multimeter 10 is attached to a mounting plate 2 provided on the substation equipment (see FIG. 3). The multimeter 10 is fixed in a state where it is inserted into a hole 2a provided in the mounting plate 2. The multimeter 10 is fixed to the mounting plate 2 with bolts or the like. The multimeter 10 is attached to the mounting plate 2 provided inside the housing 1. Note that the multimeter 10 may be attached not only to the inside of the housing 1, but also directly to a panel (e.g., the front panel) constituting the housing 1 that is exposed to the outside. In this case, the panel of the housing 1 serves as the mounting plate.

[0018] The multimeter 10 has a first portion 11 provided on the front side of the mounting plate 2 and a second portion 12 provided on the rear side of the first portion 11.

[0019] 2, a display unit 13 and various operation buttons 14 are provided on the front surface (the surface facing the viewer) of the first portion 11. Various electrical quantities (current, voltage, power, reactive power, power factor, phase angle, frequency, etc.) are displayed on the display unit 13. By operating the operation buttons 14, the type of electrical quantity displayed on the display unit 13 and the display method can be changed.

[0020] A connection terminal for connecting to a circuit of a power receiving and transforming equipment is provided in a portion of the second portion 12 disposed on the rear side of the mounting plate 2. In this embodiment, as shown in Fig. 4, the connection terminals provided are input terminals (voltage measurement input terminal 16a and current measurement input terminal 16b), output terminals (analog output terminal 17a, pulse output terminal 17b, and alarm output terminal 17c), an auxiliary power supply terminal 15, and a ground terminal 18. Wiring of the circuit of the power receiving and transforming equipment is attached to these terminals so as to satisfy the standard (tightening torque) defined by regulations.

[0021] The multimeter 10 of this embodiment is provided with a power supply terminal 20 (see FIG. 5). The power supply terminal 20 is a terminal for supplying power to the multimeter 10, and is not connected to a circuit of the power receiving and transforming equipment. The power supply terminal 20 is provided on the first portion 11 exposed on the front side of the mounting plate 2, and in the illustrated example, is provided on the underside of the first portion 11. The power supply terminal 20 of this embodiment is a terminal capable of both power supply and data communication, such as a USB terminal.

[0022] 6 shows a power supply circuit diagram of the multimeter 10. The multimeter 10 has a CPU board 31, an LED board 32, an input board 33, an output board , and a power supply board .

[0023] The CPU board 31 has a main CPU 36, an LED driver 37, and a power supply terminal (USB terminal) 20. The LED driver 37 is connected to the LED board 32. The LED driver 37 drives the LED board 32 in response to a command from the main CPU 36, whereby a value of a predetermined amount of electricity or the like is displayed on the display unit 13.

[0024] The input board 33 has input terminals (voltage measurement input terminal 16a and current measurement input terminal 16b) and a measurement circuit amplifier 38. The voltage measurement input terminal 16a and the current measurement input terminal 16b are respectively connected to a power line 50 provided in the power receiving and transforming equipment. The measurement circuit amplifier 38 is connected to the power line 50 via the voltage measurement input terminal 16a and the current measurement input terminal 16b, and measures the voltage value and current value of the power line 50.

[0025] The output board 34 has output terminals (analog output terminal 17a, pulse output terminal 17b, and alarm output terminal 17c), a pulse output circuit 40, and an alarm output circuit 41. The analog output terminal 17a, the pulse output terminal 17b, and the alarm output terminal 17c are connected to electric circuits of a power receiving board or a power distribution board.

[0026] The power supply board 35 has an auxiliary power supply terminal 15, a ground terminal 18, a power supply primary circuit 42, and a transformer 43. The auxiliary power supply terminal 15 is connected to wiring 60 provided in the power receiving and transforming equipment.

[0027] A power supply terminal 20 and a power supply board 35 are connected to a bus bar 44 provided on the CPU board 31, and power is supplied from either one of them to the bus bar 44. In the illustrated example, the power supply terminal 20 and the power supply board 35 are connected to the bus bar 44 via diodes 45, 46, respectively. As a result, the electricity supplied from the power supply terminal 20 or the electricity supplied from the power supply board 35, whichever has the higher voltage, is supplied to the bus bar 44.

[0028] After the substation equipment is assembled in a factory, the multimeter 10 is set by connecting the power source in the factory and supplying power to the equipment. The substation equipment is then shipped from the factory, transported to the installation site, and installed there.

[0029] When the power receiving and transforming equipment receives power, the high voltage electricity supplied to the power receiving and transforming equipment is reduced in pressure by a transformer, and this electricity is supplied to the power supply board 35 of the multimeter 10 via the auxiliary power terminal 15. This electricity is converted to a predetermined voltage by a power supply primary circuit 42 and a transformer 43 provided on the power supply board 35, and is then supplied to the bus bar 44 of the CPU board 31, and is then supplied to the main CPU 36, the LED driver 37, the input board 33, and the output board 34 (see the solid arrow in FIG. 7). As shown by the dotted arrow in FIG. 7, when an electrical signal output from the measurement circuit amplifier 38 of the input board 33 is transmitted to the main CPU 36 of the CPU board 31, the main CPU 36 calculates various electrical quantities based on the electrical signal input from the measurement circuit amplifier 38, and issues a command to the LED driver 37 based on the calculation result to drive the LED board 32, and causes the display unit 13 to display measured values ​​of predetermined items. Furthermore, signals (analog signals, pulse signals, alarm commands, etc.) output from the main CPU are output from output terminals 17a, 17b, and 17c of the output board .

[0030] As described above, when the power receiving and transforming equipment is receiving power, power is supplied to the multimeter 10 via the auxiliary power terminal 15, so that it is possible to check or change the settings of the multimeter 10. However, after the power receiving and transforming equipment is installed at the installation location, power is not supplied to the multimeter 10 until the power receiving and transforming equipment receives power, so that in this state it is not possible to check or change the settings of the multimeter 10.

[0031] Therefore, in the multimeter 10 of this embodiment, the power supply terminal 20 is provided on the first portion 11 exposed on the front side of the mounting plate 2. As a result, if it becomes necessary to check or change the settings of the multimeter 10 between the time when the power receiving and transforming equipment is shipped from the factory and the time when it receives power, an external power source is connected to the power supply terminal 20 of the multimeter 10. Since the power supply terminal 20 is exposed on the front side of the mounting plate 2, the external power source can be easily connected. In this embodiment, as shown in FIG. 8, a notebook computer 70 as an external power source is connected to the power supply terminal 20. As a result, it is possible to supply power from the notebook computer 70 to the main CPU 36 via the power supply terminal 20 and the bus bar 44, so that the main CPU 36 can be driven to check or change the settings of the multimeter 10. At this time, power is also supplied to the LED driver 37 and the output board 34, so that it is possible to display a predetermined item (item whose setting needs to be checked) on the display unit 13 and output an analog signal, a pulse signal, an alarm command, etc. from the output terminals 17a, 17b, and 17c of the output board 34.

[0032] In this embodiment, data can be transmitted bidirectionally between the notebook computer 70 and the multimeter 10 via the power supply terminal 20 (see the dotted arrows in FIG. 8). This allows the notebook computer 70 to be used to check and change the settings of the multimeter 10.

[0033] The present invention is not limited to the above embodiment. For example, the power supply terminal 20 is not limited to the bottom surface of the first part 11 of the multimeter 10, but may be provided on the top surface, side surface, or front surface of the first part 11. The power supply terminal 20 is not limited to a terminal capable of supplying power and communicating data, such as a USB terminal, but may be, for example, a terminal that only supplies power. The electrical equipment in which the multimeter 10 is installed is not limited to a substation equipment, but may be a feeder board or a distribution board. [Explanation of symbols]

[0034] 1 Case 2 Mounting plate 10 Digital multimeter (electronic indicating instrument) 11 Part 1 12 Part 2 13 Display section 14 Operation buttons 15 Auxiliary power terminal 16a, 16b input terminals 17a, 17b, 17c output terminals 18 Earth terminal 20 Power supply terminal 31 CPU board 32 LED board 33 Input Board 34 Output board 35 Power supply board 50 power line 60 Wiring 70 Notebook PC (external power supply)

Claims

1. An electronic indicating instrument that is attached to a mounting plate of an electrical equipment, An electronic indicating instrument having a first portion provided on the front side of the mounting plate and having a display unit, a second portion provided on the rear side of the first portion and having a connection terminal, and a power supply terminal provided on the first portion.

2. 2. The electronic indicating instrument according to claim 1, wherein the power supply terminal is a USB terminal.

3. 3. The electronic indicating instrument according to claim 2, wherein data communication is possible via the USB terminal.

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