[001] The present disclosure, in general, relates to a voltmeter to measure and indicate 3 phase incoming AC supply and more particularly, to a modular sized DIN rail mountable voltmeter to measure and indicate 3 phase incoming AC supply. The proposed modular sized DIN rail mountable voltmeter is designed for power distribution board to easily find the faults, such as, under voltage, over voltage, phase missing, phase unbalance or any voltage fluctuations.
BACKGROUND OF THE INVENTION
[002] At incomer of power distribution board, voltage indicator are used to indicate 3 phase incoming AC supply. There are various types of voltage indicators available in the market. A voltage indicator, in its simplest form, indicates the presence of a voltage near an energized power line or equipment by means of an annunciator, such as a buzzer, light or the like. More sophisticated voltage indicators may be calibrated or adjusted to indicate the presence of voltage only above a predetermined threshold and to give no indication of voltages below that threshold. Still more sophisticated indicators may give an actual indication of the magnitude of the voltage detected, by use of an analog meter display or a digital display.
[003] Voltage indicators are, in general, different from voltmeters in that they are single-point measurement devices. In other words, they contact only one line or only one point and do not measure voltage with respect to fixed reference, such as, ground or other line of different phase.
[004] In case, when there is any fault/ voltage unbalance/ under voltage/ over voltage conditions in any one phase of 3 phase supply, it is difficult to know the actual fault condition by just looking at phase indications provided by the voltage indicator.
[005] Hence, there is a need of voltage measurement at incomer of power distribution board to check and examine the fault. In market, both AC voltmeters and DC voltmeters are available. For any voltage imbalance or fault condition, it is difficult to know the actual fault condition by the available AC voltmeters. Thus, none of the available voltmeter solves the problem of detecting type and cause of fault easily without calling any maintenance, if occur in the power distribution board.
[006] Therefore, there is a need to develop a modular sized DIN rail mountable voltmeter for the power distribution board for voltage measuring and indication of 3 phase as well as 1 phase incoming AC, in a way, that can obviate the drawbacks mentioned above.
OBJECT OF THE INVENTION
[007] It is therefore an object of the present invention, to solve the aforementioned and other drawbacks existing in the existing voltage indicators or voltmeter.
[008] Another primary object of the present invention is to provide a modular sized DIN rail mountable voltmeter which can detect the type and cause of fault, such as, voltage unbalance/ under voltage/ over voltage conditions etc.
[009] Yet another objective of the present invention is to provide a modular sized DIN rail mountable voltmeter for voltage measuring and indicating for 1 phase as well as 3 phase.
[0010] Yet another object of the present invention is to provide a modular sized DIN rail mountable voltmeter which can measure voltage in the range from 80V AC to 500 V AC.
[0011] Yet another object of the present invention is to provide a modular sized DIN rail mountable voltmeter which can measure voltage in the range from 50 Hz to 60 Hz.
[0012] Yet another object of the present invention is to provide a modular sized DIN rail mountable voltmeter with less circuitry so that voltmeter can be fit in modular size.
[0013] Still yet another object of the present invention is to provide a modular sized DIN rail mountable voltmeter to digitally indicate the exact voltage in LCD display.
[0014] Still yet another object of the present invention is to provide a modular sized DIN rail mountable voltmeter which can indicate AC supply phase-wise with great accuracy.
[0015] Still yet another object of the present invention is to provide a modular sized DIN rail mountable voltmeter with very less self-power consumption.
SUMMARY OF THE INVENTION
[0016] One or more drawbacks of conventional voltage indicator and voltmeter, and additional advantages are provided through the modular sized DIN rail mountable voltmeter to measure and indicate 3 phase along with 1 phase incoming AC supply, as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be a part of the claimed disclosure.
[0017] The present subject matter relates to a modular sized DIN rail mountable voltmeter to measure and indicate 3 phase along with 1 phase incoming AC supply. The modular sized DIN rail mountable voltmeter comprises a voltage measuring and display circuit for each phase to measure the voltage phase wise and displaying the same at incomer distribution board. Each of the voltage measuring and display circuits are contrived in modular shape on the modular shaped PCB to fit within the constrain space. Each of the voltage measuring and display circuits comprises a power supply and rectification circuit, an application specific integrated circuit, a seven segment display unit and a seven segment driver circuit. The power supply and rectification circuit has a power supply component to step down the incoming AC supply to a suitable AC supply and a rectification circuit component to convert the suitable AC supply into DC supply to drive low power devices of the voltage measuring and display circuits. The application specific integrated circuit is adapted to measure the input voltage directly from the suitable AC supply with respect to neutral. The application specific integrated circuit facilitate conversion of incoming AC supply into respective digital form. The seven segment display unit displays the voltage value calculated by the application specific integrated circuit. The seven segment display driver circuit is adapted to drive the seven segment display unit. The seven segment display circuit controls the illumination of seven segment by brightness pin of the driver circuit.
[0018] In an aspect, each power supply and rectification circuit comprises a capacitor C1, plurality of diodes, a zener diode and an RC filter. The capacitor C1 is adapted to step down the incoming AC supply to the suitable AC supply. The plurality of diodes is adapted to rectify the suitable AC supply coming through the capacitor C1 to DC supply. The zener diode to regulate the DC power supply coming from the plurality of diodes to a low voltage. The RC filter is adapted to make the DC power coming from the zener diode smooth and regulated.
[0019] In an aspect, each of the application specific integrated circuit comprises an analog to digital converter, an RC time delay circuit and an encoder and a decoder. The analog to digital converter is adapted to convert the suitable AC supply input to a digital outputs within the IC. The RC time delay circuit is adapted to define sampling frequency to accurately measure the voltage of each phase. Resistors and capacitors of the RC time delay circuit are accordingly chosen for accurate measurement. The encoder and the decoder is adapted to convert the suitable AC supply to respective DC supply for supply voltage reference.
[0020] In an aspect, the ASIC of each voltage measuring and display circuits control seven segment display of that particular voltage measuring and display circuit with 10 pins.
[0021] In an aspect, the voltage measuring and display circuits for each phase are both physically and electrically isolated from each other on the Printed Circuit Board Assembly (PCBA).
[0022] In an aspect, the DIN rail mountable voltmeter is capable of measuring voltage range between 80V to 500V.
[0023] In an aspect, the DIN rail mountable voltmeter is capable of measuring AC voltage having frequency in the range between 50Hz to 60Hz.
[0024] In an aspect, the voltmeter measure and display the voltage phase wise at incomer distribution board to facilitate easy findings of voltage related faults, such as, under voltage, over voltage, phase missing, phase unbalance and voltage fluctuation.
[0025] In an aspect, in the ASIC resistors and capacitors are chosen within the range of voltage and filter outputs to display value up to 410V.
[0026] In an aspect, the seven segment display is common anode type three digit display.
[0027] In an aspect, terminals are provided on the modular voltmeter to connect to incoming AC supply and protection device.
[0028] In order to further understand the characteristics and technical contents of the present invention, a description relating thereto has been made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0029] Further objects and advantages of this invention will be more apparent from the description when read in conjunction with accompanying drawings of exemplary embodiments of invention and wherein:
[0030] Figure 1 illustrates a modular sized DIN rail mountable voltmeter to measure and indicate 3 phase along with 1 phase incoming AC supply, according to one of the embodiment of present subject matter;
[0031] Figure 2 illustrates a block diagram of the modular sized DIN rail mountable voltmeter to measure and indicate 3 phase along with 1 phase incoming AC supply;
[0032] Figure 3 illustrates the power supply and rectification circuit, according to one of the embodiment of present subject matter; and
[0033] Figure 4 illustrates pin diagram of the seven segment display according to one of the embodiment of present subject matter.
DETAILED DESCRIPTION OF THE INVENTION
[0034] Referring to Figure 1 illustrating a modular sized DIN rail mountable voltmeter 100 to measure and indicate 3 phase along with 1 phase incoming AC supply, according to one of the embodiment of present subject matter. The modular sized DIN rail mountable voltmeter 100 has terminals 101, 102 provided to connect the incoming AC supply and to connect protection device, respectively. Further, three displays 103 are provided, vertically, to indicate the determined AC supply of each phase.
[0035] Referring to Figure 2 illustrating a block diagram 200 of the modular sized DIN rail mountable voltmeter 100 to measure and indicate 3 phase along with 1 phase incoming AC supply. The modular sized DIN rail mountable voltmeter 100 comprises a voltage measuring and display circuits 200a, 200b, 200c for each phase. Each of the voltage measuring and display circuits 200a, 200b, 200c comprises a power supply and rectification circuit 201, an application specific integrated circuit 202, a seven segment display 204 and a seven segment driver circuit 203.
[0036] Each of the voltage measuring and display circuits 200a, 200b, 200c are adapted to measure the phase wise voltage and display the same at incomer distribution board on the displays 103 of the modular sized DIN rail mountable voltmeter 100. Each of the voltage measuring and display circuits 200a, 200b, 200c are designed in modular shape on the modular shaped PCB to fit within the space constrained. Each of the voltage measuring and display circuits are both physically and electrically isolated from each other on the printed circuit board assembly (PCBA). This ensures that the measured values of each of the phases are accurate and independently measured.
[0037] Referring to Figure 3 illustrating circuit diagram 300 of the power supply and rectification circuit 201, according to one of the embodiment of present subject matter. The power supply and rectification circuit 201 is adapted to step down the incoming AC supply into DC supply to drive low power components of the voltage measuring and display circuit 200a, 200b, 200c. The power supply and rectification circuit 201 has mainly two components i.e. a power supply component to step down the AC voltage of the incoming supply to a suitable AC supply value needed to drive the different components of the modular size DIN rail mountable voltmeter 100 and a rectification circuit component to rectify the suitable AC supply into a DC supply, ideal to drive these components.
[0038] The power supply and rectification circuit 201 comprises a capacitor C1, plurality of diodes D1, D2, a zener diode D3 and an RC filter C2. The capacitor C1 brings down the AC voltage of incoming supply to an AC value needed to drive the different components of the modular sized DIN rail mountable voltmeter 100. The step downed AC voltage is than passed through plurality of diodes D1, D2 adapted to rectify the AC supply coming through the capacitor C1. The plurality of diodes D1, D2 rectify the AC supply to DC. The rectified DC voltage is then passed through a zener diode D3 to regulate the DC power supply coming from the plurality of diodes D1, D2 to a low voltage needed to drive different components of the modular sized DIN rail mountable voltmeter. The regulated DC low voltage is then passes through the RC filter C2 to make the DC low voltage coming from the zener diode D3 smooth and regulated. Instead of using SMPS based supply, capacitive power supply is used because it takes less space and can be adapted into modular design.
[0039] The Application specific integrated circuit 202 is adapted to measure the input voltage from the suitable AC supply with respect to neutral. The application specific integrated circuit 202 facilitate conversion of input AC supply to respective digital form. The Application specific integrated circuit 202 comprises an analog to digital converter, an RC time delay circuit, an encoder and a decoder. The analog to digital converter converts the rectified AC inputs to digital outputs within the Integrated Circuit. The RC time delay circuit is adapted to define a sampling frequency to accurately measure the voltage of each phase. The resistors and capacitors of the RC time delay circuits are chosen accordingly, such that, the application specific integrated circuit can accurately measure the input AC supply up to 410 V.
[0040] As the Application specific integrated circuit 202 of each voltage measuring display circuits 200a, 200b, 200c are adapted to determine the input voltage from the suitable AC supply with respect to neutral, it controls seven segment display 204 of that particular voltage measuring and display circuit. All the 10 pins of seven segment display unit 204 are in connection with the pins of application specific integrated circuit 202.
[0041] Referring to Figure 4 illustrating pin diagram 400 of the seven segment display (204) according to one of the embodiment of present subject matter. The seven segment display (204) shows the value of AC supply at incomer, determined by the application specific integrated circuit 202, in a readable format. The seven segment driver circuit 203 is used to drive the seven segment display 204. The seven segment driver circuit 203 controls the illumination of seven segment display 204 by brightness control pin of driver circuit 203. The seven segment display circuit 203 is adapted to maintain constant illumination. This circuit 203 is also useful to drive the indication LED remotely through a wired connection which may leads to higher current requirement. The seven segment driver circuit 203 is adapted to perform this function also.
[0042] The seven segment display 204 is a three digit displays provided to display the AC supply voltage of each phase determined by respective application specific integrated circuit 202. A common anode type seven segment display is used to save power requirement of the modular size DIN rail mountable voltmeter 100. In an aspect, the seven segment display 204 of three digit, of 17 mm size, is used to fit inside the modular size. The all three displays of each phase are arranged to show the voltage. Indications are provided on the modular sized DIN rail mountable voltmeter 100 to differentiate between the voltages from different phases. In an aspect, indications V1 to V3 is provided on the modular sized DIN rail mountable voltmeter 100.
[0043] The proposed modular sized DIN rail mountable voltmeter 100 is adapted to measure voltage range between 80V to 500V and frequency range between 50 Hz to 60 Hz. The modular sized DIN rail mountable voltmeter 100 is designed to measure and indicate 1 phase as well as 3 phase with great accuracy. Since the modular sized DIN rail mountable voltmeter 100 measures and display the voltages phase wise at incomer distribution board, it facilitate finding of voltage related faults, such as, under voltage, over voltage, phase missing, phase unbalance and voltage fluctuation.
[0044] The modular sized DIN rail mountable voltmeter 100 is designed with less circuitry so that voltmeter can be fit in modular size. The proposed modular sized DIN rail mountable voltmeter 100 is designed to digitally indicate the exact voltage in LCD display.
[0045] The self-power consumption of proposed modular sized DIN rail mountable voltmeter 100 is very low.
[0046] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[0047] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present invention contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention. The present invention also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited feature.

Claims:We claim:
1. A modular sized DIN rail mountable voltmeter (100) to measure and indicate 3 phase along with 1 phase incoming AC supply, the modular sized DIN rail mountable voltmeter (100) comprises:
a voltage measuring and display circuits (200a, 200b, 200c) for each phase contrived in modular shape on the modular shaped PCB to fit within constrained space, to measure the phase wise voltage and displaying the same at incomer distribution board, wherein each voltage measuring and display circuits (200a, 200b, 200c) comprises:
a power supply and rectification circuit (202) having a power supply component to step down the incoming AC supply to a suitable AC supply and a rectification circuit component to convert the suitable AC supply into DC supply to drive low power devices of the voltage measuring and display circuit (200a, 200b, 200c);
an Application Specific Integrated Circuit (202) to measure the incoming voltage directly from the suitable AC supply with respect to neutral, wherein the Application Specific Integrated Circuit (202) facilitate conversion of incoming AC supply to respective digital form;
a seven segment display unit (204) to display the voltage value calculated by the Application Specific Integrated Circuit (202); and
a seven segment driver circuit (203) to drive the seven segment display unit (204), wherein the seven segment driver circuit (203) controls the illumination of seven segment display unit (204) by brightness control pin of the seven segment driver circuit (203).
2. The modular sized DIN rail mountable voltmeter (100) as claimed in claim 1, wherein each power supply and rectification circuit (201) comprises:
a capacitor C1 to step down the incoming AC supply to the suitable AC supply;
plurality of diodes (D1, D2) provided to rectify the suitable AC supply coming through the capacitor C1 to DC supply;
a zener diode (D3) to regulate the DC power supply coming from the plurality of diodes (D1, D2) to a low voltage; and
an RC filter (C2) to make the DC power coming from the zener diode (D3) smooth and regulated.
3. The modular sized DIN rail mountable voltmeter (100) as claimed in claim 1, wherein each Application Specific Integrated Circuit (202) comprises:
an analog to digital converter () to convert the suitable AC supply input to digital outputs within the Integrated Circuit;
an RC time delay circuit adapted to define sampling frequency to accurately measure the voltage of each phase, wherein the resistors and capacitors of the RC time delay circuit are accordingly chosen for accurate measurement; and
an encoder and a decoder to convert the suitable AC supply to respective DC supply for supply voltage reference.

4. The modular sized DIN rail mountable voltmeter (100) as claimed in claim 1, wherein the Application Specific Integrated Circuit (202) of each voltage measuring and display circuits (200a, 200b, 200c) control seven segment display (204) of that particular voltage measuring and display circuit with 10 pins.
5. The modular sized DIN rail mountable voltmeter (100) as claimed in claim 1, wherein the voltage measuring and display circuits (200a, 200b, 200c) for each phase are both physically and electrically isolated from each other on the Printed Circuit Board Assembly (PCBA).
6. The modular sized DIN rail mountable voltmeter (100) as claimed in claim 1, wherein the DIN rail mountable voltmeter (100) is capable of measuring voltage range between 80V to 500V.
7. The modular sized DIN rail mountable voltmeter (100) as claimed in claim 1, wherein the DIN rail mountable voltmeter (100) is capable of measuring AC voltage having frequency in the range between 50Hz to 60Hz.
8. The modular sized DIN rail mountable voltmeter (100) as claimed in claim 1, wherein the voltmeter (100) measures and display the voltage phase wise at incomer distribution board to facilitate easy findings of voltage related faults, such as, under voltage, over voltage, phase missing, phase unbalance and voltage fluctuation.
9. The modular sized DIN rail mountable voltmeter (100) as claimed in claim 1, wherein in the resistors and capacitors used in the application specific integrated circuit (202) are chosen within the range of voltage and filter outputs to display value up to 410V.
10. The modular sized DIN rail mountable voltmeter (100) as claimed in claim 1, wherein the seven segment display (204) is common anode type three digit display.
11. The modular sized DIN rail mountable voltmeter (100) as claimed in claim 1, wherein terminals (101, 102) are provided on the modular voltmeter (100) to connect to incoming AC supply and protection device.