阅读说明：本技术 电流传感器 (Current sensor ) 是由 D·F·霍耶恩 T·C·E·比尔胡耶斯 于 2019-06-18 设计创作，主要内容包括：本发明题为“电流传感器”。本发明针对一种包括外壳(2)的电流传感器,所述外壳(2)包括：－适于夹在电力电缆(5)的导线周围的第一模块(3)；－包括处理单元(6)和通信单元(7)的第二模块(4)；－所述第一模块(3)还包括测量通过所述电力电缆的导线的电流并通过第一通信链路(8)将测量的电流发送到处理单元(6)的装置；－处理单元(6)包含第一时间跟踪器；其中,所述处理单元(6)还包括如果测量的电流高于第一预定阈值则递增所述第一时间跟踪器的装置,并且通信单元(7)包括适于无线传送第一时间跟踪器的值的GSM模块。(The invention provides a current sensor. The invention is directed to a current sensor comprising a housing (2), the housing (2) comprising: -a first module (3) adapted to be clamped around the conductors of an electric power cable (5); -a second module (4) comprising a processing unit (6) and a communication unit (7); -said first module (3) further comprises means to measure the current through the conductors of said power cable and to send the measured current to a processing unit (6) through a first communication link (8); -the processing unit (6) comprises a first time tracker; wherein the processing unit (6) further comprises means for incrementing the first time tracker if the measured current is above a first predetermined threshold, and the communication unit (7) comprises a GSM module adapted to wirelessly transmit the value of the first time tracker.)

1. A current sensor comprising a housing (2), the housing (2) comprising:

-a first module (3) adapted to be clamped around the conductors of an electric power cable (5);

-a second module (4) comprising a processing unit (6) and a communication unit (7);

-said first module (3) further comprises means to measure the current through said wire and to send the measured current to a processing unit (6) through a first communication link (8);

-the processing unit (6) comprises a first time tracker;

characterized in that the processing unit (6) further comprises means for incrementing the first time tracker if the measured current is above a first predetermined threshold, and the communication unit (7) comprises a GSM module adapted to wirelessly transmit the value of the first time tracker.

2. The current sensor according to claim 1, characterized in that the housing (2) encloses a first module (3) and a second module (4).

3. Current sensor according to claim 1 or 2, characterized in that the second module (4) further comprises an energy conversion circuit (10) adapted to harvest electrical energy from the power cable (5).

4. Current sensor according to any of the preceding claims, characterized in that the second module (4) further comprises a capacitor (11) adapted to be charged by the harvested electrical energy.

5. Current sensor according to claim 4, characterized in that the capacitor (11) is adapted to supply the energy required by the GSM module to wirelessly transmit the value of the first time tracker.

6. Current sensor according to any of the preceding claims, characterized in that the second module (4) further comprises a memory module comprising a data link to the processing unit (6) and adapted to store the value of the first time tracker.

7. Current sensor according to any of the preceding claims, characterized in that the second module (4) comprises a second time tracker.

8. The current sensor of any one of the preceding claims, wherein the current sensor does not include a battery module.

9. Compressed gas network comprising an electric motor driving a compressor element and a power cable supplying electric power to the electric motor, wherein the compressed gas network (13) comprises a current sensor (1) according to any of the preceding claims.

10. A method for determining the functioning of a device driven by an electric motor connected to an electric power cable (5) by measuring the current through a portion of the conductors of said cable (5), the method comprising the steps of:

-providing a current sensor (1) having a housing (2), the housing (2) having a first module (3) and a second module (4);

-clamping the first module (3) around the conductors of the power cable (5);

-providing a processing unit (6) and a communication unit (7) part of the second module (4);

-measuring the current through the wire and sending the measured current to the processing unit (6) through the first communication link (8);

characterized in that the method further comprises the steps of: providing a first time tracker to a processing unit (6); comparing the measured current with a first predetermined threshold and incrementing a first counter of the first time tracker if the measured current is above the first predetermined threshold; whereby the method further comprises the step of transmitting the value of the first time tracker through the GSM module part of the communication unit (7).

11. The method of claim 10, further comprising the step of transmitting the value of the first time tracker to an external device.

12. The method according to claim 10 or 11, characterized in that if the current is below a predetermined threshold value, the method further comprises the step of increasing a second counter of the first time tracker.

13. The method of claim 12, further comprising storing the value of the first counter and/or the value of the second counter to a memory module portion of the current sensor.

14. The method according to claim 12 or 13, characterized in that the method further comprises transmitting the value of the sum between the first counter and the second counter and the value of the first counter or the second counter by the GSM module after a predetermined time interval measured by the second time tracker.

15. Method according to any of claims 10-14, characterized in that the method further comprises running an initialization phase for the current sensor (1) during a predetermined time interval.

16. The method according to any one of claims 10-15, further comprising harvesting electrical energy from the power cable (5) and charging a capacitor (11) portion of the current sensor.

17. The method according to any of claims 10-16, characterized in that the capacitor (11) provides the necessary power to the communication unit (7).

18. The method according to any one of claims 10 to 17, further comprising the step of pre-configuring ports of a toggle switch as part of the second module (4) such that each port comprises a first predetermined threshold.

19. The method according to any one of claims 10 to 18, further comprising identifying the current sensor (11) by an IMEI code of a GSM module.

20. Use of a current sensor according to any one of claims 1 to 8 for determining the number of operating hours of a compressor or dryer.

Technical Field

The invention relates to a current sensor comprising a housing, said housing comprising:

-a first module adapted to be clamped around a conductor of an electric power cable;

-a second module comprising a processing unit and a communication unit;

-said first module further comprises means for measuring the current through said conductor and for transmitting the measured current to a processing unit via a first communication link;

-the processing unit comprises a first time tracker.

Background

Devices for measuring current, such as the device disclosed in US 2015/137596, are used in industry. Such devices measure the current through the cable and send the measurement results to a management system via the internet. The device also includes a control unit capable of routing energy harvested from the cable to the plurality of storage devices based on the switching and load balancing decisions.

Disclosure of Invention

The above-described devices are not the simplest and cost-effective solution for sensing current on a single device.

Furthermore, since the device is sending measured current, it requires a large amount of energy to operate. Accordingly, the above-described apparatus includes multiple energy storage units, thereby increasing the manufacturing costs and potential maintenance costs of the apparatus.

Furthermore, since all the measurements are sent to the management system, the above-mentioned device cannot provide any information about the functioning of the units on the cable to which it is connected without further processing. In order to extract relevant information therefrom, the user of such a device must query the management system and analyze the raw data. This step becomes cumbersome since the amount of data easily becomes too large.

In view of the above-mentioned drawbacks, it is an object of the present invention to provide a current sensor having a very simple topology, having a minimum number of components and requiring no installation of additional cabling or maintenance procedures.

The current sensor according to the invention is intended to provide information about the operation of the equipment connected to the power cable and to help the user to identify when to schedule a maintenance procedure based on their specific usage pattern.

The present invention aims to provide a current sensor that is easy to manufacture, cost effective and deployable in all geographical areas.

The present invention solves at least one of the above and/or other problems by providing a current sensor comprising a housing, the housing comprising:

-a first module adapted to be clamped around a power cable;

-a second module comprising a processing unit and a communication unit;

-the first module further comprises means for measuring the current through the power cable and sending the measured current to a processing unit through a first communication link;

-the processing unit comprises a first time tracker;

wherein the processing unit further comprises means for incrementing the first time tracker if the measured current is above a first predetermined threshold, and the communication unit comprises a GSM module adapted to wirelessly transmit the value of the first time tracker.

Since the processing unit comprises means for incrementing the first time tracker when the current is above the first predetermined threshold, and since the value of the first time tracker is a value transmitted by the GSM module, the current sensor according to the invention in fact reduces the amount of data sent by the GSM module in a very simple manner, without risking losing important information. Thus, instead of sending each measurement, the current sensor only sends a value representative of the device.

The energy consumption for data transfer of the GSM module is also reduced due to the reduced amount of data sent.

Preferably, the tracked first time comprises a first counter that is incremented each time the measured current is above a predetermined threshold.

By simply adding the first counter, the technical requirements of the current sensor of the invention are minimal, which means a reduction of the manufacturing costs and thus of the maintenance costs.

Since the current sensor increments the first counter each time the measured current is above a predetermined threshold, the current sensor according to the invention enables more complex analyses, such as the number of hours a device connected to the power cable is running. The number of operating hours of the device can thus be determined in a very simple and user-friendly manner.

Since the current sensors use a GSM module for transmitting data, the complexity of the network is very low. Such networks do not require repeaters or additional gateways in the transfer of data. The current sensor according to the present invention is capable of directly transmitting data to an external computer or cloud.

Furthermore, the user of the current sensor does not need to come into the vicinity of the device to which the current sensor is connected in order to receive data. Thus, the manufacturing costs of the present current sensor, as well as the costs associated with providing and maintaining a network through which such current sensors transmit data, are even lower.

Preferably, the current sensor is installed on a power cable of an apparatus selected from the group consisting of a compressor, a vacuum pump, a dryer, and the like.

Currently, for such equipment, the typical period of maintenance procedures is set to once or twice a year, depending on the type of equipment and the industry in which it is used. The period is selected to be a period of: after which the device is considered to have been running for a certain number of hours. However, by using the current sensor according to the invention, such a maintenance process can be scheduled when the actual number of operating hours has been used, which can delay the maintenance process to, for example, once a year or once every two years.

Since users of such devices may rely on them to operate for longer periods of time without interruption, maintenance costs are reduced and the reliability of the device is increased.

Since the current sensor has such a structure, it can be mounted on the power cable in a quick and non-invasive manner without requiring a technician to go to the site.

Preferably, the second module further comprises a capacitor adapted to be charged by the electric energy harvested from the power cable.

By including a capacitor, the current sensor according to the invention is self-powered.

Therefore, it does not require an additional wire or connector, and it can be simply clamped around the wire of the power cable and used.

The invention is also directed to a compressed gas network comprising a motor driving a compressor element and a power cable supplying power to said motor, wherein the compressed gas network comprises a current sensor according to the invention.

The invention is also directed to a method for determining the operation of a device driven by an electric motor connected to an electric power cable by measuring the current through a conductor portion of said electric power cable, the method comprising the steps of:

-providing a current sensor having a housing with a first module and a second module;

-clamping the first module around the wires of the power cable;

-providing a processing unit and a communication unit part of the second module;

-measuring the current through the wire and sending the measured current to the processing unit through the first communication link;

wherein the method further comprises the steps of providing a first time tracker to a processing unit, comparing the measured current with a first predetermined threshold and incrementing a first counter of the first time tracker if the measured current is above the first predetermined threshold; whereby the method further comprises the step of transmitting the value of the first time tracker through the GSM module part of the communication unit.

The invention is also directed to the use of a current sensor according to the invention for determining the number of operating hours of a compressor or dryer.

In the context of the present invention, it will be appreciated that the benefits presented above with respect to current sensors are also valid for compressors or vacuum pumps comprising current sensors, for methods and uses of such current sensors.

Drawings

In order to better illustrate the characteristics of the invention, some preferred configurations according to the invention are described below, by way of example and without any limitative character, with reference to the accompanying drawings, in which:

FIG. 1 schematically illustrates a current sensor according to an embodiment of the invention;

FIG. 2 schematically illustrates a second module according to an embodiment of the invention; and

fig. 3 schematically shows a device with a current sensor according to the invention mounted on a power line.

Detailed Description

Fig. 1 shows a current sensor 1 comprising a housing 2 with a first module 3 and a second module 4.

The first module 3 is clamped around the power cable 5.

The power cable 5 transmits electrical energy from a source such as, for example, an electrical grid or generator to equipment such as, for example, a gas compressor, a compressed gas dryer or a vacuum pump and allows the equipment to operate.

By clamping around the power cable, it will be understood that the first module 3 covers the outer circular part of the conductor part of the power cable and may be locked or fixed in place by any means, such as but not limited to snap-fitting, screws, bolts, fixing elements such as clips, by screwing the second module 4 onto the first module 3 or by gluing, etc.

Preferably, for a single-phase cable, the first module 3 is clamped around only one conductor of the power line 5: either around the phase line or around the neutral line.

In the case where the power cable 5 is a three-phase cable, the current sensor 1 may be mounted on any one of the three conductive wires.

The second module 4 comprises a processing unit 6 and a communication unit 7.

The first module 3 further comprises means for measuring the current through the conductor parts of said power cable 5 and sending the measured current to the processing unit 6 through the first communication link 8.

By means of a device for measuring an electric current is meant that the first module 3 is able to detect an electric signal flowing through a conductor portion of the power cable 5, said signal comprising information about the intensity and/or voltage of the electric current flowing therethrough. Furthermore, from this detection signal, a value of the current intensity can be derived.

The first module 3 includes, for example but not limited to: hall effect sensors, transformers or clamp-on ammeters, fluxgate transformer type sensors, Rogowski coils, etc.

A communication link refers to an electrical connection, such as an electrical conductor, for example, a wire or an electrical connection on a Printed Circuit Board (PCB). If the telecommunications module comprises wires, the wires typically comprise a connector at each end. Such a communication link allows data to be transferred between the two components.

It is not excluded that the communication link is wireless, which is the case when both components each comprise a transceiver or one component comprises a transmitter and the other component comprises a receiver.

Furthermore, the processing unit 6 comprises a first time tracker.

Preferably, said first time tracker is reset to have a zero value before the current sensor 1 is clamped around a wire portion of the power cable 5.

However, it should not be excluded that the first time tracker may be activated before being clamped around the wire with a different value representing the actual number of hours the device has been running until then, or an approximation thereof.

The processing unit 6 further comprises means for comparing the measured current intensity with a first predetermined threshold value and, if the result of the comparison shows that the value of the current intensity is higher than or equal to the first predetermined threshold value, means for incrementing a first counter part of the first time tracker.

Preferably, the incrementing process takes into account the last value of the first counter to which the first predetermined value was added.

The first predetermined value is selected to be any value or the first predetermined value is equal to the time period between two consecutive current measurements.

By way of example, but not limitation, the first predetermined value may be selected to be any value between about one second and about ten minutes, more preferably between about five seconds and about five minutes, and even more preferably between about ten seconds and about one minute.

In a preferred embodiment, but not limited thereto, the time period between two current measurements is chosen to be about ten seconds.

Thus, if the comparison result indicates that the current intensity is higher than or equal to the first predetermined threshold, the processing unit increments the last value of the first counter by 10 seconds.

If it is the first measurement, the processing unit adds zero to ten seconds, the new value of the first counter to be used in the subsequent steps being ten seconds. This process is a looping process until the first time tracker is reset.

Preferably, the first time tracker is reset after the maintenance procedure is performed.

Furthermore, the communication unit 7 comprises a GSM module adapted to wirelessly transmit the value of the first time tracker.

The communication unit 7 comprises a second communication link 9 receiving the value of the first time tracker from the processing unit 6.

Preferably, the GSM module further comprises a SIM card.

Preferably, but not limited thereto, for a more compact and easily manufactured current sensor, the housing 2 encloses a first module 3 and a second module 4.

It is further preferred that the housing 2 comprises a moving part allowing the first module 3 to be easily mounted around the wire part of the power cable 5.

Preferably, the second module 4 further comprises an energy conversion circuit 10 adapted to collect electrical energy from the conductor portions of the electrical power cable 5.

The energy conversion circuit 10 is preferably capable of receiving signals from the first module 3 and of amplifying or reducing the harvested energy.

The first module typically includes a first coil wound around a portion of the first module 3 and allows the first module to sense a magnetic field generated by current flowing through the wire.

Furthermore, an image of the current is induced in the current transformer part of the energy conversion circuit 10, which is sent to the processing unit 6 for further processing. The processing unit 6 extracts the value of the current intensity from the received image.

The energy conversion circuit 10 is also capable of harvesting energy from the current image.

Thus, the image of the current is used to convert the current into a voltage by using, for example, the current to voltage converter.

Furthermore, the energy conversion circuit 10 preferably uses a voltage modulation technique to charge the capacitor 11. The voltage modulation comprises AC (alternating current) to DC (direct current) and/or DC (direct current) to DC (direct current) converters.

Preferably, the level of the voltage is changed to another voltage level, and then energy is transferred to the capacitor 11 portion of the second module 4 to charge it.

The energy conversion circuit 10 supplies the necessary amount of energy to the processing unit 6, preferably via the first communication link 8.

The energy conversion circuit 10 is connected to the capacitor 11 via a third communication link 12.

In a preferred embodiment according to the invention, the capacitor 11 is adapted to supply the energy required by the GSM module to wirelessly transmit the value of the first time tracker.

Said capacitor 11, after being charged, preferably supplies the communication unit 7 with the necessary energy for wirelessly transmitting the value of the first time tracker.

Thus, the current sensor according to the invention is self-powered, and the user only needs to clamp it around the power supply line.

Preferably, in order to allow the capacitor to charge, the current sensor 1 according to the invention is allowed to clamp around the conductor for a minimum period of time while the device is running, before the first value of the first time tracker is sent.

The capacitor 11 is selected to be any type of capacitor. Preferably, the capacitor is of the type that is resistant to the temperatures and vibrations typically generated by a compressor, vacuum pump or dryer, and has a long service life.

As regards their capacitance, the current sensor 1 according to the invention can use any capacitor 11 that can provide sufficient energy for the data transmitted through the GSM module, such as for example but not limited to a capacitor with a capacitance chosen between 1 farad and 20 farad, more preferably between 10 farad and 15 farad.

In another embodiment according to the invention, the second module 4 further comprises a memory module (not shown) comprising a data link to the processing unit 6 and adapted to store the value of the first time tracker.

Thus, the current sensor 1 may transmit the value of the first time tracker after a preset time interval according to the user's requirements.

The preset time interval is selected to be any time interval chosen between, for example, a few hours and a few days.

In a preferred embodiment, but not limited thereto, the preset time interval is chosen to be one every 24 hours.

This approach reduces even more energy consumption, since the wireless communication is not initiated after each measurement of the current strength, but after said preset time interval.

Preferably, the communication unit transmits the last value of the first time tracker upon initiation of the wireless communication.

The user may also retrieve all values of the first time tracker in the order of measurement, if desired.

This method can provide a usage pattern of the device.

The memory module is any type of memory module, preferably but not limited thereto, the memory module is of a non-volatile type.

In another preferred embodiment, but not limited thereto, the memory module has the capability of storing all values of the first time tracker measured during a preset time interval.

In another embodiment according to the present invention, the wireless communication unit 7 may transmit the value of the first time tracker to a central controller, a cloud, or an external device.

In another preferred embodiment according to the invention, the communication unit 7 may send all stored values to a central controller, cloud or external device and reset the memory module when said memory module is full.

Preferably, it will hold the last value of the first time tracker.

In one embodiment according to the invention, but not limited to, the memory module is adapted to write data to different sectors after each reset in order to extend the lifetime of the memory module.

By employing this technique, the sectors are protected from damage and it is ensured that the memory module is not full until a preset time interval is reached.

In another embodiment according to the present invention, the communication unit 7 may transmit the saved value of the first time tracker to a central controller, cloud, or external device when the capacitor 11 is fully loaded.

In yet another embodiment according to the present invention, the first time tracker further comprises a second counter. The second counter tracks the time the device is in the unloaded state.

Thus, if the measured current intensity is below the first predetermined threshold but not equal to zero, the second counter is incremented.

If the measured current strength is equal to zero, the processing unit 6 preferably does not increment any counter.

Preferably, the second counter is incremented in the same manner as the first counter by taking into account the last value of the second counter to which the second predetermined value is added. The second predetermined value is preferably the same as the first predetermined value.

However, it should not be excluded that the second predetermined value is selected to have a different value than the first predetermined value.

Typically, a compressor or vacuum pump is considered to be in an unloaded state when it is operating at a very low speed and when there is very little or no demand on the network connecting such compressor or vacuum pump.

Typically, the unloaded condition is considered when the compressor or vacuum pump is operating at about twenty percent of nominal power.

It should also not be excluded that said first predetermined value and/or said second predetermined value are chosen as numbers or characters representing moments of time at which maintenance is recommended to be performed on the device, but different from the frequency of the measurements.

In another preferred embodiment according to the invention the communication unit 7 is adapted to send the current values of the first counter and the second counter each time a communication is initiated.

In a further preferred embodiment, the first time tracker preferably, but not exclusively, adds the value of the first counter to the value of the second counter after each measurement of the current.

Preferably, the result of the summation is stored on a memory module and transmitted via the communication unit 7.

The value of the sum represents the total number of hours of operation of the device.

In another embodiment according to the invention the communication unit 7 is adapted to transmit the latest value of the sum and at least one of the value of the first counter or the value of the second counter.

However, it should not be excluded that both the value of the first counter and the value of the second counter may be transmitted together with the result of the summation.

The first counter and the second counter are two software variables of the first time tracker. The first counter indicates the amount of time the device remains in the loaded state and the second counter indicates the amount of time the device remains in the unloaded state. In another embodiment according to the invention, the second module 4 comprises a second time tracker.

Such a second time tracker provides an additional check to ensure that the current sensor 1 delivers the value of the first time tracker after a preset time interval.

The second time tracker retrieves either the actual time of day or is reset each time a communication is made after a preset time interval and keeps track of the preset time interval.

In another embodiment according to the invention, and without being limited thereto, the current sensor 1 may send the current value of the first time tracker and/or all values of the first time tracker after a preset time interval, saved on the memory module, when the capacitor 11 is fully loaded.

In yet another embodiment according to the present invention, the communication unit 7 transmits only the value of the first time tracker saved since the last communication to the central controller, the cloud, or the external device, thereby avoiding duplication of data.

Preferably, but not limited to this, the communication unit 7 will send a result indicating the sum of the total number of operating hours and at least one of the value of the first counter or the value of the second counter to the central controller, the cloud or the external device.

In a preferred embodiment according to the invention, the current sensor 1 according to the invention does not comprise a battery module.

In one embodiment of the invention, the current sensor 1 according to the invention may be mounted within a housing (not shown) of the holding device, or even outside such a housing.

Thus, the current sensor 1 according to the invention is visible and easily accessible.

The current sensor 1 according to the invention is suitable to be mounted on any type of compressor, vacuum pump or dryer.

In another embodiment according to the invention, the current sensor 1 may be mounted on the power line 5 of a compressed gas network 13 (fig. 3). The compressed gas network 13 includes compressor elements driven by fixed speed or variable speed motors.

The electric motor comprises an electric line through which electric energy is supplied from the grid or from the generator. The wires are connected either directly or indirectly to the power cable 5.

In the context of the present invention, the compressed gas network 13 is to be understood as a complete compressor installation comprising the compressor element, all typical connecting pipes and valves, the housing of the compressor and possibly the motor driving the compressor element.

In the context of the present invention, a compressor element is to be understood as a compressor element housing in which the compression process takes place by means of a rotor or by means of a reciprocating movement.

In the context of the present invention, the compressor element may be selected from the group comprising screw, sawtooth, claw, scroll, vane, centrifugal, piston, etc.

In another embodiment according to the invention, the compressed gas network 13 may comprise a compressed gas dryer. The compressed gas dryer includes a motor having an electrical cord connected thereto or an electrical cord connected to a controller portion of the dryer.

Thus, the current sensor of the present invention may be installed either on the electric wire of the motor or on the electric wire of the controller and count the operation time of the compressed gas dryer.

In another embodiment according to the invention, if the compressed gas network 13 comprises two or more devices (not shown), each comprising an electric motor with electric wires or electric wires simply supplying electric energy to their respective circuits, the current sensor 1 according to the invention can be mounted on each of these electric wires and count the operating time of each individual device.

Preferably, the current sensor 1 is installed on the conductor of the power cable of the compressor, vacuum pump or dryer with a power ranging between 2 kw and 22 kw.

Such devices are typically in a low power range and are used, for example and without limitation, in the following situations: in a plant for powering pneumatic tools, in a household or even in an industrial environment.

However, the use of such a current sensor 1 for devices in the high power range should not be excluded.

It should be understood, however, that the current sensor 1 according to the present invention is not intended to be mounted on a wire of a power cable of an HVAC system.

In order to facilitate a very easy installation on different equipment with different power characteristics, the current sensor 1 according to the invention further comprises a toggle switch (not shown) comprising several pre-configured ports, each typically for a different compressor, dryer or vacuum pump.

In an embodiment according to the invention, each port preferably comprises a first predetermined threshold characteristic of a particular type of compressor, dryer or vacuum pump.

Once the port on the toggle switch is selected, the current sensor 1 will retrieve the first predetermined threshold value corresponding to that port and use it for comparison with the measured current intensity.

In another embodiment according to the invention, the current sensor 1 may comprise a temperature sensor allowing a user to retrieve data about the environment in which the device is operating or about the temperature of the device itself.

The current sensor 1 is also able to receive information from sensors mounted on the device via a wireless connection and provide a more detailed analysis of the device.

Thus, a user of the current sensor 1 according to the invention can retrieve not only data about the operating mode of the device, such as energy consumption, number of operating hours for which the device has not been switched off, next scheduled maintenance, but also information about other parameters potentially affecting the operating capacity of such a device, such as ambient temperature, temperature of the device at different locations, and possibly even humidity and dew point.

The operation of the current sensor 1 is very simple and as follows.

The current sensor 1 is clamped around a wire portion of a power cable 5 of a device such as a compressor or a vacuum pump, the current through the wires of the power cable 5 is measured, and the measured current is sent to the processing unit 6 through a first communication link 8.

The measurement of the current may be converted to a certain value before being sent to the processing unit 6, or the processing unit may convert the measurement to a certain value after receiving it.

Furthermore, the processing unit compares the measured current intensity with a first predetermined threshold value and increments a first counter of the first time tracker if the measured current intensity is higher than the first predetermined threshold value. The value of the first time tracker is transmitted to the central controller, the cloud or the external device through the GSM module.

The external device is any type of device, such as, for example and without limitation: an external hard drive, a computer, a tablet, a telephone, or a Personal Digital Assistant (PDA), etc.

Preferably, the external device is able to receive data via a GSM type connection.

The processing unit 6 preferably comprises a microprocessor (not shown). The microprocessor is typically of a very low power and low cost type capable of performing the above-described comparisons and steps.

Preferably, the current sensor 1 can be identified by a unique code provided to the GSM module, such as for example but not limited to: an International Mobile Equipment Identity (IMEI) code or an Integrated Circuit Card Identifier (ICCID) or any other type of code.

In another embodiment according to the present invention, a Quick Response (QR) code may be provided for each device.

In an embodiment according to the invention, a user of the current sensor 1 according to the invention may retrieve information about the current values of the first counter and/or the second counter from the cloud or directly from the current sensor 1 by accessing a website and identifying the device by a unique code, such as an IMEI code, and/or scanning the QR code, or by scanning said QR code to query the current sensor 1.

Preferably, the method according to the invention comprises an initialization phase of operating the current sensor 1 during a predetermined time interval, thereby allowing the current sensor 1 to reach a nominal operating state.

Preferably, between measurements, the current sensor 1 enters a sleep mode in order to conserve energy.

The method further comprises harvesting electrical energy from the power cable and charging the capacitor 11 part of the second module 4. Typically, after an initialization phase, the current sensor 1 will charge the capacitor 11 with sufficient energy to be able to start and perform wireless communication through the GSM module.

In an embodiment according to the invention and without being limited thereto, said initialization phase may be chosen to be any value chosen between 2 hours and 24 hours, more preferably between 2 hours and 15 hours, even more preferably between 2 hours and 8 hours.

Typically, the capacitor 11 should be fully or almost fully charged after about 8 hours.

In another embodiment according to the invention, the method comprises the step of pre-configuring the ports of the toggle switch part of the second module 4 to respectively contain the first predetermined threshold.

The user of the current sensor 1 according to the invention only has to select the desired port and mount the current sensor 1 on the conductor. By doing so, the current sensor 1 is adapted to the specific compressor or vacuum pump he uses.

In one embodiment according to the invention, the values of the first counter and/or the second counter sent to the cloud or to the external device are being monitored to assist the user in scheduling maintenance of the device.

Furthermore, if no value is received within a time period such as, for example, but not limited to, a month, two months or several weeks, an alert signal may be sent to the user informing him that the device is off, depending on the user's requirements.

The alarm signal is sent to a central controller, the cloud, or an external device monitored by the user.

The alarm signal is even a text message sent to the mobile phone.

Thus, if the device is turned off for a period of time that allows the capacitor 11 to empty, the current sensor 1 will require the least amount of time to reach a reasonable state of charge once turned on.

Tests have shown that if the capacitor 11 is allowed to fully empty, the current sensor 1 takes about two hours to operate again.

It is further preferred that upon restarting the device the sum, the last value of the first counter and/or the second counter is retrieved from the memory module.

The sum, the last sent value of the first counter and/or the second counter can also be retrieved from a central controller, the cloud or an external computer.

Depending on the design of the current sensor 1 and/or the compressed gas network comprising such a current sensor 1, the current sensor 1 and/or the compressed gas network may comprise some or even all of the technical features presented herein in any combination, without departing from the scope of the present invention.

The technical characteristics at least mean that: a housing 2, a first module 3, a second module 4, a processing unit 6, a communication unit 7, a capacitor 11, a moving part of the housing 2, an energy conversion circuit 10, a third communication link 12, a memory module, a first time tracker, a first counter, a second counter, a transmission value after a preset time interval, a second time tracker, a toggle switch, a temperature sensor, a microprocessor, a SIM card, an initialization phase, a sleep mode, a port pre-configured for the toggle switch, etc.

The invention is by no means limited to the embodiments described as examples and shown in the drawings, but such a current sensor 1 can be implemented in various types of modifications without departing from the scope of the invention.