Electronic Pressure Switch

Abstract

Electronic pressure switch comprising a pressure sensor and a circuit provided in turn with a switch for the activation/deactivation of an electric pump, an input terminal and an output terminal for connection to the mains and connection between the pressure switch and the electric pump and a microcontroller for controlling the switch, which receives signals from the pressure sensor, wherein the electric circuit comprises a current sensor connected to the microcontroller, so that it can stop the operation of the electric pump due to overcurrent, thus avoiding having to mount a specific sensor in the electric pump. It also allows, by interacting with the pressure sensor through a programmed logic, an operation of the electric pump in no-load condition, without water, as well as water hammers, to be detected with greater reliability.

Claims

1. An electronic pressure switch comprising: a) a protective housing; b) a pressure sensor; c) a circuit provided with: i) a switch for the activation/deactivation of an electric pump ii) terminals for connection between the pressure switch and the electric pump, iii) a power supply terminal, d) a microcontroller for controlling the switch, which receives signals from the pressure sensor, wherein the electrical circuit comprises a current sensor connected to the microcontroller, wherein the pressure sensor, the electrical circuit and the microcontroller are arranged on the inside of the protective housing, such that it constitutes an electronic pressure switch with autonomous protection functions.

2. The pressure switch according to claim 1, wherein the current sensor comprises a Hall probe or a coil sensor.

3. The pressure switch according to claim 1, wherein the pressure sensor consists of a pressure sensor and a transducer.

4. The pressure switch according to claim 1, wherein the microcontroller is configured to open the switch in the case of simultaneous detection of a current below a minimum current threshold by the current sensor and of a pressure below a minimum pressure.

5. The pressure switch according to claim 1, wherein the microcontroller is configured to open the switch in the case of detection of a current above a maximum current threshold by the current sensor.

6. The pressure switch according to claim 1, wherein the microcontroller can be programmed to operate according to: a) a mode in which the switch closes when the pressure sensor detects the falling to a pressure below a minimum pressure and the switch opens when the pressure sensor detects the rising to a pressure above a maximum pressure; b) a mode in which the switch opens when the pressure sensor detects a pressure below a minimum pressure, c) a mode in which the switch opens when the pressure sensor detects a pressure above a maximum pressure, or d) a mode in which the switch opens when the pressure sensor detects the falling to a pressure below a minimum pressure and the switch closes when the pressure sensor detects the rising to a pressure above a maximum pressure.

7. The pressure switch according to claim 1, wherein the microcontroller is configured to measure the number of pressure oscillations per time unit.

8. The pressure switch according to claim 7, wherein the microcontroller is configured to emit an alarm signal or to open the switch if the number of cycles of starting and stopping of the pump per time unit exceeds a maximum frequency.

9. The pressure switch according to claim 1, comprising a user interface for setting the parameters of the pressure switch, the user interface comprising a keyboard, indicator lights and a display screen.

10. The pressure switch according to claim 1, wherein the microcontroller is a programmable microcontroller.

11. The pressure switch according to claim 1, comprising a power supply.

12. The pressure switch according to claim 3, wherein the switch, the current sensor, the terminals and the power supply are arranged on a first board and the microcontroller, the keyboard and the display screen are arranged on a second board.

13. The pressure switch according to claim 12, wherein the first board and second board are arranged at different levels, one above the other.

14. The pressure switch according to claim 9, wherein the switch, the current sensor, the terminals and the power supply are arranged on a first board and the microcontroller, the keyboard and the display screen are arranged on a second board.

15. The pressure switch according to claim 14, wherein the first board and second board are arranged at different levels, one above the other.

16. The pressure switch according to claim 11, wherein the switch, the current sensor, the terminals and the power supply are arranged on a first board and the microcontroller, the keyboard and the display screen are arranged on a second board.

17. The pressure switch according to claim 16, wherein the first board and second board are arranged at different levels, one above the other.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0055] To complete the description and to assist a better understanding of the invention's characteristics, according to an example of a practical embodiment thereof, accompanying as an integral part of the description is a set of figures, wherein, in an illustrative and non limiting way, the following has been represented:

[0056] FIG. 1 is an exploded view of an electronic pressure switch.

[0057] FIG. 2 is a perspective view of an assembled electronic pressure switch.

[0058] FIG. 3 is a block diagram of the pressure switch according to the invention. It does not correspond to an electrical diagram.

[0059] FIG. 4 is a very schematic diagram showing how the components are arranged on the support boards and their arrangement on two levels.

[0060] FIG. 5 is a perspective view of the pressure switch from which the top cover of the housing has been withdrawn and in which the relative arrangement of the boards can be seen.

[0061] FIGS. 6 to 8 are different views of a fitting provided with the housing for the electronic pressure switch and a non-return valve integrated into the fitting itself.

DESCRIPTION OF A PREFERRED MODE FOR CARRYING OUT THE INVENTION

[0062] As can be seen in FIG. 3, the invention generally relates to an electronic pressure switch 1 comprising: [0063] a pressure sensor 2 and [0064] a circuit 3 provided with: [0065] a switch 31 for the activation/deactivation of an electric pump 4, [0066] terminals 33 for connection between the pressure switch 1 and the electric pump 4, [0067] a power supply terminal 32, [0068] a microcontroller C for controlling the switch 31, which receives signals from the pressure sensor 2.

[0069] The operation is as follows: the device is generally provided with a metric thread 52 which is screwed in a pressure taking point of a hydraulic circuit. Thus, it contacts the fluid with the pressure sensor 2. This sends the measure signal to the microcontroller, which decides, depending on the programming parameters, how to act on the switch 31 to open or close the power circuit of the electric pump 4. For the connection of the pressure switch 1 to the electric pump 4 terminals 33 which are passed through the hole 53 are arranged. The terminal 32 is passed through a hole 51 of the housing 5 and corresponds to the power supply of the device through the mains.

[0070] As can be seen in FIG. 3, the electrical circuit 3 comprises a current sensor 34, in this embodiment arranged in series, the current sensor 34 being connected to the microcontroller C.

[0071] Therefore, apart from interacting with the pressure sensor 2, the microcontroller C, which preferably is a programmable microcontroller, will receive signals from the current sensor 34, which allows to establish a logical decision-making for the protection of the electric pump 4, which is not limited to only pressure. In particular, the microcontroller will be able to act on the switch 31 through only the signal received from the pressure sensor, and through only the signal received from the current sensor or through combining the signals from both sensors.

[0072] As can be seen in FIGS. 1 to 3, the device comprises a protective housing 5, within which the pressure sensor 2, the electrical circuit 3 and the microcontroller C are housed.

[0073] With the incorporation in the pressure switch of the current sensor 34 and its connection to the microcontroller C, the latter can be configured to open the switch 31 in the case of detection simultaneously of a current I below a minimum current threshold by the current sensor 34 and a pressure below a minimum pressure Pmin. Therefore, the interaction of these three elements provides additional protection to the electric pump, greater than the detection of the absence of water based solely on the pressure sensor 2.

[0074] Another possibility provided by the invention is that of configuring the microcontroller C to open the switch 31 in the case of detection of a current I above a maximum current threshold by the current sensor 34. Therefore, instead of having to provide a specific overcurrent sensor in the electric pump 4 itself, it is sufficient to have the pressure switch of the present invention.

[0075] According to another embodiment, the microcontroller is configured to operate according to: [0076] a mode in which the switch 31 closes when the pressure sensor 2 detects the falling to a pressure below a minimum pressure Pmin and the switch 31 opens when the pressure sensor 2 detects the rising to a pressure above a maximum pressure Pmax; or according to [0077] a mode in which the switch 31 opens when the pressure sensor 2 detects a pressure below a minimum pressure Pmin, or according to [0078] a mode in which the switch 31 opens when the pressure sensor 2 detects a pressure above a maximum pressure Pmax, or according to [0079] a mode in which the switch 31 opens when the pressure sensor 2 detects the falling to a pressure below a minimum pressure Pmin and the switch 31 closes when the pressure sensor 2 detects the rising to a pressure above a maximum pressure Pmax.

[0080] According to another embodiment, the microcontroller C is configured to measure the number of pressure oscillations per time unit, and therefore, the rapid cycles can be measured and action taken accordingly.

[0081] For example, the microcontroller C may be configured to emit an alarm signal or to open the switch 31 if the number of cycles of starting and stopping of the pump per time unit exceeds a maximum frequency. This situation may occur, for example, when an air boiler becomes depressurised, leading to water hammers on each starting/stopping of the electric pump and an undesired increase in the pump's motor's maneuvers, therefore, reducing its useful life.

[0082] As can be seen in FIG. 2, a user interface 6 is provided for setting the parameters of the pressure switch. This interface, as can be seen in FIG. 5, comprises a keyboard B and a display screen P, matching with the corresponding holes in the top of the housing.

[0083] As can be seen in FIGS. 4 and 5, the switch 31, the current sensor 34, the terminals 33 and the power supply are arranged on a first board P1. On the other hand, the microcontroller C, the keyboard B and the display screen P are arranged on a second board P2. The first board P1 and second board P2 are arranged at different levels, one above the other.

[0084] Here a fitting, which can operate in combination with the pressure switch of the present invention, is also described.

[0085] The five-way fittings are used to connect the hydraulic circuit to a hydrosphere, a pressure switch and a gauge provided with a reading dial. A first way is for inlet, a second for outlet, a third, facing up when installed, is for connecting a hydrosphere or boiler, a fourth is for the pressure switch and a fifth is for a gauge.

[0086] It may be the case that the pressure switch incorporates a gauge, in which case the fitting may be only four-way, or simply a lid is screwed on the remaining way.

[0087] The installation is usually completed with a non-return valve, as is shown in the FIGS. 6 to 8, which is arranged upstream from the fitting. It can be arranged between the pump and the fitting, or upstream of the pump, in this case to prevent the loss of prime of the pump.

[0088] Therefore, this implies the installer must anticipate the installation of a non-return valve, which implies an additional component, further installation work and, in some cases, occupation of more space of the installation.

[0089] To resolve this problem, the inventors have also designed a fitting of at least four ways, each equipped with a channel and a screw thread, the first way being intended for connection to the pump, while a second way is intended for the connection with the consumption part, a third way for the connection of a pressure switch and a fourth way being intended for the connection of a hydrosphere which is characterised in that, in the channel corresponding to the first way, comprising a non-return valve.

[0090] Therefore, instead of having to provide a non-return valve, the fitting itself is provided with said valve. Moreover, it is not a valve added and attached to the inlet of the fitting, but the fixed part of the valve is composed of material of the fitting itself, the moving part or parts of the valve being arranged in the channel.

[0091] In the case of a gravity-actuated non-return valve, the moving part can be a ball, and the supporting surface of the ball is arranged in the inlet channel itself of the fitting. Also it could be a ball or equivalent provided with a spring.

[0092] The valve can be four or five-way, and can be of plastic or brass, or any other material suitable for its specific use

[0093] The pressure switch of the invention described above can be integrated in the fitting itself, as is shown in FIG. 6. Thus, the connection between pressure switch and the fitting is eliminated, which achieves even greater integration. In this case, it is sufficient that the fitting, which is converted into a smart fitting, have only three-ways.

[0094] Therefore, in the present document a three-way fitting provided with an electronic pressure switch as that claimed is also described.

[0095] In summary, the present invention aims to, through management through software of the interaction of the different electronic components, perform the functions that a traditional electro-mechanical pressure switch performs with greater precision and to incorporate new protection functions that are traditionally resolved with the addition of devices specific to the hydraulic or electric system.

[0096] In this text, the word comprises and its variants should not be interpreted in an exclusive way, i.e. they do not exclude the possibility that that which is described includes other elements.

[0097] On the other hand, the invention is not limited to the specific embodiments that have been