Pressure gauge power supply unit

Abstract

Aspects of the invention relate to a power supply unit (31) configured to be integrated into a vacuum pressure gauge (1) comprising an ionizing vacuum pressure sensor (3) having an anode (7) and a cathode (9). The power supply unit (31) includes a mother board (55) and a daughter board (65). The mother plate (55) has a first surface (57A) and a second surface (57B). A transformer (37) having a primary coil (W1) and a secondary coil (W2) is mounted to the mother board (55). The daughter board (65) has one or more first electrical connectors (41-n) for supplying power to the ionizing vacuum pressure sensor (3), the one or more first electrical connectors (41-n) including a high voltage (HV) first electrical connector (41-1) electrically connected to a secondary coil (W2) of the transformer (37). A high voltage (HV) first electrical connector (41-1) is configured to be connected to an anode (7) of an ionization vacuum pressure sensor (3). The daughter board (65) is mounted to the first surface of the mother board (55), one or more first electrical connectors (41-n) on the daughter board (65) being spaced apart from the first surface of the mother board (55). Aspects of the invention relate to: a vacuum pressure gauge (1) comprising a power supply unit (31); a mounting arrangement of the power source (31) to the vacuum pressure sensor (31); and a method of manufacturing the power supply unit (31).

Description

Technical Field

[0001] The present disclosure relates to a pressure gauge power supply unit. Aspects of the invention relate to a power supply unit, a pressure gauge and a method of manufacturing a pressure gauge. The pressure gauge is typically a vacuum pressure gauge for measuring vacuum pressure. Background Art

[0002] Pressure gauges are commonly used to measure pressure in industrial systems. Pressure measurements can be used to check that a system has the appropriate pressure for its intended purpose. For example, a vacuum pressure gauge can be used in a vacuum system. If the measurement indicates that the pressure in the system is not low enough, this can be used to indicate and detect leaks or defects in the system, and / or provide feedback to help control a vacuum pump that evacuates the system.

[0003] This specification generally exemplifies pressure sensors for vacuum pressure gauge assemblies as "pressure transducers," which are generally known to generate a signal (e.g., an electrical signal) as a function of the pressure applied thereto. As will be appreciated by those skilled in the art, a variety of suitable pressure transducers and vacuum pressure gauge assemblies are known, and it is understood that any such suitable types of pressure transducers and pressure gauge assemblies, or combinations thereof, may benefit from the present disclosure and are therefore within the scope of the present disclosure.

[0004] This type of vacuum gauge assembly may include, for example, a Pirani vacuum gauge assembly, a thermocouple vacuum gauge assembly, an ionization vacuum gauge assembly (e.g., a hot cathode vacuum gauge assembly or a cold cathode vacuum gauge assembly (such as a Penning vacuum gauge assembly)), a magnetron vacuum gauge assembly, an inverted magnetron vacuum gauge assembly, a wide range vacuum gauge assembly, a strain gauge assembly, etc.

[0005] Since the working principles of such a vacuum pressure gauge assembly and the pressure transducer (ie, the pressure sensing element) therein are well known to those skilled in the art, they will not be described in further detail herein.

[0006] It is an object of the present invention to provide an improvement over known vacuum pressure gauges. Summary of the invention

[0007] Aspects and embodiments of the present invention provide a power supply unit configured to be integrated into a vacuum pressure gauge, the vacuum pressure gauge including an ionization vacuum pressure sensor having an anode and a cathode; wherein the power supply unit includes:

[0008] a motherboard including a first surface and a second surface, wherein a transformer having a primary coil and a secondary coil is mounted to the motherboard; and

[0009] a daughterboard including one or more first electrical connectors for supplying power to the ionization vacuum pressure sensor, the one or more first electrical connectors including a high voltage (HV) first electrical connector electrically connected to a secondary coil of the transformer, the high voltage (HV) first electrical connector being configured to connect to an anode of the ionization vacuum pressure sensor;

[0010] Wherein, the daughterboard is mounted to the first surface of the motherboard, and one or more first electrical connectors on the daughterboard are spaced apart from the first surface of the motherboard. The one or more first electrical connectors are arranged on the daughterboard to provide an increased spacing between the first electrical connector or each first electrical connector and an electrical component such as a transformer mounted to the motherboard. At least in some embodiments, this can reduce the risk of arc discharge. The power supply unit can be integrated into the vacuum pressure gauge to form an independent device. For example, the power supply unit and the vacuum pressure gauge can be arranged in a housing.

[0011] The transformer may include an auxiliary winding.

[0012] The power supply unit may include one or more voltage multipliers. One or more voltage multipliers may be provided to multiply the voltage output from the transformer. The transformer and the one or more voltage multipliers may be arranged in a flyback topology. At least in some embodiments, the voltage multiplier may enable the vacuum pressure gauge to have a relatively low response time. The one or more voltage multipliers may be disposed on a motherboard.

[0013] The power supply unit may optionally include a step-down power supply. The reduced power may help reduce or eliminate the effects of input supply variability on the output from the transformer. The step-down power supply may be a step-down converter, such as a buck-type converter.

[0014] The power supply unit may include one or more high voltage resistors. The high voltage resistor may be connected between the transformer and the output from the power supply unit. If the power supply unit includes one or more voltage multipliers, the high voltage resistor may be arranged between the one or more voltage multipliers and the output from the power supply unit.

[0015] The daughter board can be surface mounted to the first surface of the motherboard. The daughter board can be installed using a surface mount assembly process. This can facilitate the assembly of the power supply unit. For example, the daughter board can be surface mounted to the motherboard at the same time as other electrical components.

[0016] The one or more first electrical connectors may be surface mounted to the daughterboard. Alternatively, the one or more first electrical connectors may be mounted to the daughterboard via through holes. This may provide enhanced structural integrity for the one or more first electrical connectors.

[0017] The motherboard may include at least one control interface connector for connecting to the control unit. The at least one control interface connector may be arranged on the second surface of the motherboard. The at least one control interface connector may be surface mounted on the second surface of the motherboard. The at least one control interface connector may include or consist of one or more input / output pins. The one or more input / output pins may extend perpendicular to the second surface of the motherboard. The at least one control interface connector may include a (pin) pin header electrical connector. The pin header electrical connector may be surface mounted or may be through-hole mounted.

[0018] In at least some embodiments, the one or more first electrical connectors may each include a socket for receiving a connector pin to establish an electrical connection.The or each socket may include a central axis extending substantially perpendicular to the first surface of the motherboard.

[0019] The daughterboard may include at least one channel to form a space between the motherboard and the daughterboard. The at least one channel may be formed in a second surface of the daughterboard, which is positioned against the first surface of the motherboard. The at least one channel may be machined in the daughterboard, for example. The at least one channel may extend at least partially around one of the first electrical connectors. For example, the at least one channel may extend at least partially around one of the first electrical connectors configured to supply high voltage (HV) to the ionization vacuum pressure sensor. The space between the motherboard and the daughterboard may be filled with an electrical potting compound.

[0020] The daughterboard may include a plurality of first electrical connectors. The plurality of first electrical connectors may include a first and a second of the first electrical connectors. The daughterboard may include a cut-out formed between the first and the second of the first electrical connectors. The first of the first electrical connectors may, for example, be a high voltage (HV) electrical connector. The cut-out may extend through the daughterboard and may help to electrically isolate the first and the second of the first electrical connectors from each other. The cut-out may be filled with an electrical potting compound.

[0021] An aperture may be formed on the motherboard. The aperture may extend through the motherboard. A transformer may be disposed in the aperture. The transformer may be mounted to the second surface of the motherboard. The daughterboard may be formed to extend around the periphery of the transformer. The periphery of the daughterboard may extend around the periphery of the transformer. The daughterboard may include a recess for accommodating the transformer.

[0022] The first surface of the motherboard may be an underside of the motherboard.

[0023] The daughterboard may include a first surface and a second surface. The first electrical connector may be disposed on the first (upper) surface of the daughterboard. The second surface of the daughterboard may be disposed adjacent to the first surface of the motherboard, for example in a face-to-face mounting arrangement. The second surface of the daughterboard may be mounted to the first surface of the motherboard.

[0024] The first electrical trace may be disposed on the first surface of the motherboard. The second electrical trace may be disposed on the second surface of the daughterboard. An electrical connection may be established between the first and second electrical traces. The one or more first electrical connectors may be electrically connected to the second electrical trace. For example, the one or more first electrical connectors may extend through the daughterboard and be electrically connected to the second electrical trace.

[0025] The power supply unit may include an electrical potting compound. At least a portion of the first surface of the motherboard and at least a portion of the daughterboard may be encapsulated in the electrical potting compound. At least in some embodiments, the electrical potting compound forms a permanent protective layer that forms an integral part of the power supply unit. The electrical potting compound protects the electronic components and may provide electrical insulation and / or improved mechanical strength.

[0026] An electrical potting compound may be disposed on at least a portion of the first surface of the daughterboard.

[0027] The first electrical connector is preferably not obstructed by the electrical potting compound.The electrical potting compound is not disposed on the first electrical connector.

[0028] An electrical potting compound is disposed at least partially around an outer circumference of the daughterboard. The electrical potting compound may be at least substantially flush with the first (upper) surface of the daughterboard.

[0029] The space formed between the motherboard and the daughterboard may be at least substantially filled with an electrical potting compound.The cut-away portion formed in the daughterboard may be at least substantially filled with an electrical potting compound.

[0030] According to another aspect of the present invention, there is provided a vacuum pressure gauge, comprising a power supply unit as described herein. The power supply unit may be integrated into the vacuum pressure gauge.

[0031] The vacuum pressure gauge may include a vacuum pressure sensor. The vacuum pressure sensor may include or consist of an ionization vacuum pressure sensor. The vacuum pressure sensor may include or consist of a hot cathode or cold cathode ionization vacuum pressure sensor.

[0032] Aspects and embodiments of the present invention provide a power supply unit configured to be integrated into a vacuum pressure gauge including an ionization vacuum pressure sensor having an anode and a cathode, the power supply unit comprising:

[0033] a motherboard including a first surface and a second surface, wherein a transformer having a primary coil and a secondary coil is mounted to the motherboard;

[0034] Therein, an aperture is formed in the motherboard, and the transformer is at least partially disposed in the aperture of the motherboard.

[0035] The aperture may extend through the motherboard.The transformer may be a planar transformer disposed at least partially in the aperture.

[0036] The transformer may include opposing first and second major surfaces.The first major surface of the transformer may be substantially aligned with or protrude above the first surface of the motherboard.

[0037] The power supply unit may include a daughterboard including one or more first electrical connectors for supplying power to the ionization vacuum pressure sensor. The one or more first electrical connectors may include a high voltage (HV) first electrical connector electrically connected to a secondary coil of the transformer.

[0038] The daughter board may be mounted to the first surface of the motherboard. The daughter board may be surface mounted to the first surface of the motherboard. The daughter board may be mounted using a surface mount assembly process. This may facilitate assembly of the power supply unit. For example, the daughter board may be surface mounted to the motherboard simultaneously with other electrical components. One or more first electrical connectors provided on the daughter board may be spaced apart from the first surface of the motherboard.

[0039] The one or more first electrical connectors may be surface mounted to the daughterboard. Alternatively, the one or more first electrical connectors may be mounted to the daughterboard via through holes. This may provide enhanced structural integrity for the one or more first electrical connectors.

[0040] The periphery of the daughterboard may be shaped to extend around the periphery of the transformer.The daughterboard may include a recess to accommodate the transformer.

[0041] The transformer may be surface mounted to a surface of the motherboard. The transformer may be mounted to a first surface or a second surface of the motherboard.

[0042] The power supply unit may include one or more voltage multipliers. The one or more voltage multipliers may be disposed on a motherboard.

[0043] The power supply unit may be removably mounted to the ionization vacuum pressure sensor.

[0044] According to another aspect of the present invention, there is provided a vacuum pressure gauge, comprising a power supply unit as described herein. The power supply unit may be integrated into the vacuum pressure gauge.

[0045] The vacuum pressure gauge may include a vacuum pressure sensor. The vacuum pressure sensor may include or consist of an ionization vacuum pressure sensor. The vacuum pressure sensor may include or consist of a hot cathode or cold cathode ionization vacuum pressure sensor.

[0046] Any control unit or controller described herein may suitably include a computing device having one or more electronic processors. The system may include a single control unit or electronic controller, or alternatively, different functions of the controller may be specifically implemented or hosted in different control units or controllers. As used herein, the term "controller" or "control unit" will be understood to include both a single control unit or controller and a plurality of control units or controllers that operate together to provide any of the control functions. In order to configure a controller or control unit, a set of suitable instructions may be provided, which, when executed, causes the control unit or computing device to implement the control technology specified herein. This set of instructions may be suitably embedded in the one or more electronic processors. Alternatively, the set of instructions may be provided as software stored on one or more memories associated with the controller to be executed on the computing device. The control unit or controller may be implemented in software running on one or more processors. One or more other control units or controllers may be implemented in software running on one or more processors, optionally, the one or more processors being the same as the first controller. Other suitable arrangements may also be used.

[0047] Within the scope of the present application, it is expressly intended that the various aspects, embodiments, examples and alternatives set forth in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular individual features thereof, may be employed independently or in any combination. That is, all embodiments and / or features of any embodiment may be combined in any manner and / or combination, unless such features are incompatible. Applicants reserve the right to change any initially filed claim or to file any new claim accordingly, including the right to amend any initially filed claim to be subordinate to and / or combined with any feature of any other claim, even though the right was not originally claimed in this manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] One or more embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0049] Figure 1 A perspective view showing a vacuum pressure gauge according to an embodiment of the present invention;

[0050] Figure 2 Shows Figure 1 A circuit diagram of a power supply unit in the vacuum pressure gauge shown;

[0051] Figure 3 showing a perspective view of a first side of a power supply unit without an electrical potting compound;

[0052] Figure 4showing a perspective view of a first side of a power supply unit with an electrical potting compound;

[0053] Figure 5 showing a perspective view of a second side of the power supply unit;

[0054] Figure 6 showing a perspective view of a first side of a daughterboard for mounting a first electrical connector in a power supply unit;

[0055] Figure 7 Shows Figure 6 a perspective view of a second side of the daughterboard;

[0056] Figure 8 A perspective view showing an electrical connector on a vacuum pressure sensor used in a vacuum pressure gauge according to an embodiment of the present invention;

[0057] Fig. 9 shows a schematic representation of a controller for a control unit in a vacuum pressure gauge;

[0058] Fig.10 A first perspective view showing a control unit and a power supply for mounting into a chassis of a vacuum pressure sensor;

[0059] Fig.11 showing a second perspective view of a control unit and power supply for mounting into a chassis of a vacuum pressure sensor;

[0060] Fig.12 shows a perspective view of a mold tool used to form an electrical potting compound on a power supply unit; and

[0061] Fig.13 Shown is a method for supporting multiple Fig.12 A perspective view of the fixture of the mold tool is shown. DETAILED DESCRIPTION

[0062] A vacuum pressure gauge 1 according to an embodiment of the present invention will now be described with reference to the accompanying drawings. The vacuum pressure gauge 1 is used to measure the vacuum pressure of a vacuum system component, generally indicated by the reference numeral VSC. The vacuum system component VSC may be in the form of a vacuum pump, for example.

[0063] Figure 1 1 shows a perspective view of the assembled vacuum pressure gauge 1. The vacuum pressure gauge 1 includes an ionization vacuum pressure sensor 3. In this embodiment, the ionization vacuum pressure sensor 3 is a cold cathode ionization vacuum pressure sensor. The ionization vacuum pressure sensor 3 includes a cathode 5 and an anode 7 (in Figure 2). In use, a high voltage is applied to the anode 7, and negatively charged electrons leave the cathode 5 by field emission and travel toward the anode 7. The electrons ionize neutral gas molecules, thereby generating a gas discharge current, which is measured to determine the vacuum pressure. The ionization vacuum pressure sensor 3 also includes a Pirani filament (not shown) and a trigger filament (not shown). In one variation, the ionization vacuum pressure sensor 3 can be a hot cathode ionization vacuum pressure sensor. Other types of vacuum gauge sensors can be used in the vacuum pressure gauge 1.

[0064] The vacuum pressure gauge 1 comprises a base 9, a body 11 and an (upper) end member 13. The vacuum pressure gauge 1 comprises a central longitudinal axis X. The body 11 is elongated along the central longitudinal axis X. In the present embodiment, the body 11 is generally cylindrical in shape and has a circular profile in cross section. The body 11 comprises a housing 15 arranged around the ionization vacuum pressure sensor 3. The housing 15 comprises a tubular sleeve in the form of a right cylinder. As described herein, the housing 15 is removable from the vacuum pressure gauge 1. The upper end of the housing 15 is closed by the end member 13. At least one external interface connector 17 is provided in the end member 13 for connection to an external computing device (not shown). The vacuum pressure gauge 1 in the present embodiment also comprises a status indicator 19. The status indicator 19 is in the form of a ring extending around the circumference of the end member 13. In use, at least a portion of the status indicator 19 can be controllably illuminated to indicate the operating state of the vacuum pressure gauge 1 and / or the operating pressure measured by the ionization vacuum pressure sensor 3. The status indicator 19 may comprise one or more light emitting devices (not shown), such as light emitting diodes (LEDs). It will be appreciated that the body 11 of the vacuum pressure gauge 1 may have different shapes and / or contours. For example, the body 3 may have a cross-section in the form of a polygon or a rounded polygon.

[0065] The body 11 may be made of any suitable material, such as stainless steel or aluminum alloy, or a polymer material (where operating conditions and temperature permit). The body 11 may also be made by any suitable manufacturing method, such as by molding / casting, machining from a solid block, or 3D printing.

[0066] The base 9 is configured to be fastened to a vacuum system component VSC, for example, using one or more mechanical fasteners. A flange 21 extends from the base 9 in a radial direction. In one example, the flange 21 is of NW25 specification, although any suitable size and shape of flange may be used within the scope of the present disclosure. The flange 21 includes a mating surface 23 for docking with a vacuum system component VSC from which pressure is measured. The mating surface 23 may optionally include an annular recess (not shown) for receiving an O-ring to provide a seal between the vacuum pressure gauge 1 and the vacuum system component VSC.

[0067] The flange 21 includes an inlet passage (not shown) for a chamber formed in the ionization vacuum pressure sensor 3. The inlet passage extends axially from the mating surface, through the flange 21 and into the chamber. The inlet passage is in fluid communication with the chamber and allows working gas to enter and exit (e.g., from the vacuum system component VSC) during use. A filter element (not shown) can be arranged across the inlet passage for filtering the working gas before the working gas enters the chamber. The filter element helps prevent contaminants from entering the chamber. The filter element can, for example, include stainless steel (e.g., 316L) 30-2 mesh, although any other suitable type (e.g., membrane), material, and specification of filter element can be used within the scope of the present disclosure.

[0068] By "working gas or process gas" is meant the gas(es) whose pressure the component is intended to measure. The "working gas" is typically the gas(es) being processed (e.g., being evacuated by the vacuum system component VSC). The pressure of the gas in the chamber can provide an indication of the pressure in the vacuum system.

[0069] The vacuum pressure gauge 1 comprises a power supply unit 31 and a control unit 35. The power supply unit 31 is configured to supply power to the ionization vacuum pressure sensor 3. In use, the power supply unit 31 outputs a high voltage to the anode 7 of the ionization vacuum pressure sensor 3. The power supply unit 31 is integrated into the vacuum pressure gauge 1. Figure 2 , a circuit diagram 200 for the power supply unit 31 is shown. The circuit diagram 200 includes a schematic representation of the ionization vacuum pressure sensor 3. The power supply unit 31 includes a transformer 37 having a primary coil W1, an auxiliary coil W2, and a secondary coil W3. In the present embodiment, the transformer 37 is a planar transformer, although other types of transformers may be used. The transformer 37 includes first and second opposing major surfaces 39A, 39B. The secondary coil W3 is connected to the anode 7 of the ionization vacuum pressure sensor 3. The power supply unit 31 includes a plurality of first electrical connectors 41-n for connecting to the ionization gauge sensor 3. In the present embodiment, the first electrical connectors 41-n each include an electrical socket.

[0070] like Figure 2As shown, the power supply unit 31 includes one or more voltage multipliers 43-n. In the present embodiment, a plurality of voltage multipliers 43-n are provided. The voltage multiplier 43-n is provided to multiply the voltage output from the secondary coil W3 of the transformer 37. The voltage multiplier 43-n can, for example, enable the generation of a voltage of up to 5kV. The transformer 37 and the voltage multiplier 43-n are arranged in a flyback topology with an operating frequency in the range of 10 to 100KHz. Advantageously, the voltage multiplier 43-n can make the response time of the vacuum pressure gauge 1 relatively low. The output capacitance of the transformer 37 can be reduced. The voltage multiplier 43-n can be arranged in a small area, so that the footprint of the power supply unit 31 is compact. The power supply unit 31 optionally includes a primary step-down power supply 45 to reduce or eliminate the influence of input supply variability on the high voltage output from the transformer 37. Regardless of the input supply, the high voltage output can remain at least substantially unchanged. In the present embodiment, the primary step-down power supply 45 is a step-down converter (buck converter).

[0071] The power supply unit 31 includes one or more high voltage resistors 47-n connected between the voltage multiplier 43-n and the high voltage output. The resistor 47-n limits the current and output power from the power supply unit 31. The voltage applied to the ionization vacuum pressure sensor 3 can vary during ignition depending on operating conditions. For example, ignition can occur more easily at higher pressures than at lower pressures. The resistor 47-n can limit the voltage applied to the ionization vacuum pressure sensor 3 (e.g., during ignition). The resistor 47-n allows a larger voltage at a lower vacuum pressure to assist in the ignition of the ionization vacuum pressure sensor 3. The resistor 47-n can also provide secondary protection to prevent user misuse.

[0072] The mounting arrangement of the transformer 37 and the first electrical connector 41-n in the power supply unit 31 will now be described in more detail. The power supply unit 31 includes a first printed circuit board (PCB) 55 having a first (lower) surface 57A and a second (upper) surface 57B; and a second printed circuit board (PCB) 65 having a first (lower) surface 67A and a second (upper) surface 67B. The first printed circuit board 55 has a substantially circular profile for positioning within the body 11 of the vacuum pressure gauge. The first printed circuit board 55 can have different profiles. The second printed circuit board 65 is mounted to the first surface 57A of the first printed circuit board 55 in a face-to-face arrangement. The second printed circuit board 65 has a thickness of approximately 4.5 mm. The thickness of the second printed circuit board 65 can be greater than or less than 4.5 mm. In the present embodiment, the second printed circuit board 65 is surface mounted to the first printed circuit board 55. Other techniques can be used to mount the second printed circuit board 65 to the first printed circuit board 55. The first and second printed circuit boards 55, 65 include corresponding first and second electrical traces to establish an electrical connection. The first printed circuit board 55 is referred to herein as a motherboard 55 ; and the second printed circuit board 65 is referred to herein as a daughterboard 65 .

[0073] like Figure 3 and 5As shown, the motherboard 55 includes a through hole 73 for receiving the transformer 37. The transformer 37 is mounted to the second surface 57B of the motherboard 55 and is at least partially positioned in the through hole 73. This mounting arrangement reduces the vertical packaging requirements of the transformer 37 in the body 11 of the vacuum pressure gauge 1. The first main surface 39A can be aligned or offset with the first surface 57A of the motherboard 55. In this embodiment, the transformer 37 is mounted so that the first main surface 39A protrudes outward from the first surface 57A of the motherboard 55. The voltage multiplier 43-n and the high-voltage resistor 47-n are mounted to the first surface 57A of the motherboard 55. The power supply unit 31 includes at least one control interface connector 59-n for communicating with the control unit 35. Mounted to the second surface 57B of the motherboard 55. In this embodiment, the power supply unit 31 includes first and second control interface connectors 59-1, 59-2. The first and second control interface connectors 59-1, 59-2 each include a plurality of input / output pins 61, such as general purpose input output (GPIO) pins. The input / output pins 61 may be provided, for example, in a pin header unit. The input / output pins 61 protrude substantially perpendicularly to the second surface 57B. The input / output pins 61 are configured to be positioned in a complementary connector (not shown) provided on the control unit 35. The control unit 35 is mounted on the power supply unit 31 in a hardware attached on top (HAT) configuration. At least one of the first and second control interface connectors 59-1, 59-2 is configured to output a control signal from the control unit 35 to the power supply unit 31. The first and second control interface connectors 59-1, 59-2 may also be used to supply power to the power supply unit 31.

[0074] like Figure 3 and 4 As shown, the power supply unit 31 includes a plurality of first electrical connectors 41-n. The first electrical connectors 41-n are mounted in the daughter board 65. In the present embodiment, the first electrical connectors 41-n are mounted in the daughter board 65 by through holes, but other mounting techniques may be used. This mounting arrangement provides a vertical offset between the first electrical connectors 41-n and other components in the power supply unit 31 (such as the transformer 37). This separation can reduce the risk of arc discharge between components, such as arc discharge caused by high voltage output. Figure 6 A perspective view of a first surface 67A of the daughter board 65 (separated from the mother board 55 ); and a perspective view of a second surface 67B of the daughter board 65 (separated from the mother board 55 ) are shown.

[0075] like Figure 8As shown, the ionization vacuum pressure sensor 3 includes a plurality of second electrical connectors 71-n. The first electrical connector 41-n and the second electrical connector 71-n have complementary profiles. The first electrical connector 41-n and the second electrical connector 71-n are aligned with each other. In the assembled vacuum pressure gauge 1, the first and second electrical connectors 41-n, 71-n cooperate with each other to establish an electrical connection between the power supply unit 31 and the ionization vacuum pressure sensor 3.

[0076] In the present embodiment, each of the first electrical connectors 41-n includes an electrical socket. Each of the electrical sockets includes a central longitudinal axis Xn extending substantially parallel to the central longitudinal axis X of the vacuum pressure gauge 1. Each of the second electrical connectors 71-n includes an electrical pin. Each of the electrical pins includes a central longitudinal axis Xn extending substantially parallel to the central longitudinal axis X of the vacuum pressure gauge 1. The vacuum pressure gauge 1 is assembled by aligning the first and second electrical connectors 41-n, 71-n and moving the power supply unit 31 and the ionization vacuum pressure sensor 3 relative to each other in the axial direction (i.e., along the longitudinal axis X). Each of the second electrical connectors 71-n is positioned in a corresponding one of the first electrical connectors 41-n to establish an electrical connection. In a variant, the first electrical connectors 41-n may each include an electrical pin; and the second electrical connectors 71-n may each include an electrical socket. Other types and / or combinations of the first and second electrical connectors 41-n, 71-n may be used.

[0077] The plurality of first electrical connectors 41-n include a high-voltage first electrical connector 41-1 for connecting to the anode 7 of the ionization vacuum pressure sensor 3. The plurality of first electrical connectors 41-n also include a chassis circuit first electrical connector 41-2; a high-voltage circuit first electrical connector 41-3, a first trigger filament first electrical connector 41-4, a second trigger filament first electrical connector 41-5; a Pirani filament A first electrical connector 41-6; a Pirani filament B first electrical connector 41-7 and a compensator first electrical connector 41-8. The plurality of second electrical connectors 71-n include a high-voltage second electrical connector 71-1 for connecting to the high-voltage first electrical connector 41-1. The plurality of second electrical connectors 71-n also include a chassis circuit second electrical connector 71-2; a high voltage circuit second electrical connector 71-3, a first trigger filament second electrical connector 71-4, a second trigger filament second electrical connector 71-5; a Pirani filament A second electrical connector 71-6; a Pirani filament B second electrical connector 71-7 and a compensator second electrical connector 71-8. It will be understood that one or more of the first and second electrical connectors 41-n, 71-n may be omitted. If the trigger filament is omitted from the ionization vacuum pressure sensor 3, the first and second electrical connectors 41-4, 41-5, 71-4, 71-5 for the trigger filament may be omitted. Alternatively or additionally, if the Pirani filaments A and B are omitted from the ionization vacuum pressure sensor 3, one or more of the first and second electrical connectors 41-6, 41-7, 71-6, 71-7 for the Pirani filaments A and B may be omitted.

[0078] like Figure 3 As shown, the daughter board 65 has an outer profile including a recess 77. The recess 77 is formed to maintain a gap between the transformer 37 and the daughter board 65. At least one channel 79 is formed in the second surface 67B of the daughter board 65 to form a space or gap between the motherboard 55 and the daughter board 65. Figure 7 As shown, the at least one channel 79 extends at least partially around the base of the high voltage first electrical connector 41-1. The at least one channel 79 in this embodiment is bifurcated (generally Y-shaped), but other configurations are also contemplated. The daughterboard 65 also includes at least one cutout or aperture 81. Figure 6 As shown, a cutout 81 is formed between two or more of the first electrical connectors 41-n to provide improved electrical insulation. In this embodiment, the cutout 81 is formed between the high voltage first electrical connector 41-1 and the Pirani filament A second electrical connector 71-6; and the compensator second electrical connector 71-8.

[0079] like Figure 4As shown, an electrical potting compound 83 is provided on the electrical components disposed on the first surface 67A of the daughter board 65. The electrical potting compound 81 is provided to electrically insulate the components, for example, to prevent arc discharge between the high-voltage first electrical connector 41-1 and other components or connectors. The electrical potting compound 83 can also mechanically strengthen the power supply unit 31. At least a portion of the first surface 57A of the motherboard 55 is encapsulated in the electrical potting compound 83. In the present embodiment, the electrical potting compound 83 is not applied on the second surface 57B of the motherboard 55. The electrical potting compound 83 can have a depth greater than or equal to the thickness of the daughter board 65. In the present embodiment, the electrical potting compound 83 is at least partially applied on the first surface 67A of the daughter board 65. The electrical potting compound 83 is not applied on the first electrical connector 41-n. For example, when the electrical potting compound 83 is applied, the first electrical connector 41-n can be sealed or covered. The electrical potting compound 83 is applied using a vacuum molding process, but other techniques can also be used.

[0080] The control unit 35 is configured to control the operation of the ionization vacuum pressure sensor 3. Fig. 9 As shown, the control unit 35 includes a pressure sensor controller 91, which includes at least one electronic processor 93 and a memory (storage) device 95. A set of computational instructions is stored on the memory device 95. When executed, the computational instructions cause the at least one electronic processor 93 to control the ionization vacuum pressure sensor 3 according to the method described herein. The at least one processor 93 includes at least one electrical input 97-n for receiving an input signal ISS; and at least one electrical output 99-n for outputting a control signal PSS. The input signal ISS may, for example, include a pressure reading from the ionization vacuum pressure sensor 3. An external interface connector 17 is mounted to the control unit 35 and is supported in the end member 13 of the vacuum pressure gauge 1. The external interface connector 17 is in electrical communication with the at least one electronic processor 93 and can receive power and / or communicate with an external user interface (not shown) in use. In this way, the external interface connector 17 can be connected to a power source and / or an external user interface or device (e.g., a computer) by a cable for communicating with the at least one electronic processor 93. In the illustrated arrangement, the interface connector 17 is a D-sub connector. Thus, the interface connector 17 may be connected to a power source and / or an external user interface using a cable having a complementary D-sub connector. In other embodiments, any other suitable connector may be used, such as an RJ45 or USB connector.

[0081] like Fig.10 and 11As shown, the power supply unit 31 and the control unit 35 are mounted in the chassis 101. The chassis 101 includes a pair of diametrically opposed first and second brackets 103A, 103B, which are configured to engage the edges of the power supply unit 31 and the control unit 35. The chassis 101 may include a single bracket, or more than two brackets. The first and second brackets 103A, 103B are positioned in corresponding first and second positioning recesses 105A, 105B formed in the outer periphery of the power supply unit 31. The first and second brackets 103A, 103B are positioned in the first and second positioning recesses 105A, 105B to axially and / or angularly position the power supply unit 31. The first and second brackets 103A, 103B are also positioned in a recess (not shown) formed in the control unit 35 to axially and / or angularly position the control unit 35. The chassis 101 includes opposing first and second elastic arms 107A, 107B. The chassis 101 may include a single elastic arm, or more than two elastic arms. The first and second resilient arms 107A, 107B are configured to releasably engage the outer side wall of the ionization vacuum pressure sensor 3. Figure X XX, the end member 13 is integrally formed with the chassis 101. First and second apertures 109A, 109B are formed in the end member 13 for receiving mechanical fasteners (not shown) to fasten the control unit 35 to the chassis 101. Other techniques may be used to fasten the control unit 35 and / or the power supply unit 31 to the chassis 101. An end plate 111 may optionally be provided on the end member 13. The chassis 101 helps to reduce or prevent relative movement of the power supply unit 31 and the control unit 35, thereby reducing the mechanical load applied to the first and second control interface connectors 59-1, 59-2. In one variation, the chassis 101 may be omitted. For example, one or more mechanical fasteners may be used to fasten the control unit 35 to the power supply unit 31 without a separate chassis 101. The housing 15 may optionally be fastened to the chassis 101.

[0082] The control unit 35 is mounted to the power supply unit 31 to form a subassembly, which can be removably mounted to the ionization vacuum pressure sensor 3. In this embodiment, the subassembly includes a chassis 101, but the chassis 101 may be omitted. Fig.10As shown, the first electrical connector 41-n is arranged on the lower side of the subassembly. The power supply unit 31 is axially moved in a first direction (toward the ionization vacuum pressure sensor 3) to introduce each of the second electrical connectors 71-n into a corresponding one of the first electrical connectors 41-n. The power supply unit 31 and the control unit 35 are thus mounted on the ionization vacuum pressure sensor 3. The power supply unit 31 can be removed from the ionization vacuum pressure sensor 3. The power supply unit 31 is axially moved in a second direction (away from the ionization vacuum pressure sensor 3) to move the second electrical connector 71-n out of the corresponding first electrical connector 41-n. In this embodiment, the power supply unit 31 and the control unit 35 are removed as a single unit together with the chassis 101 and the housing 15. The housing 15 is fixed in place to limit or prevent access to the power supply unit 31.

[0083] As described above, the ionization vacuum pressure sensor 3 is secured to a base 9 which, in use, is secured to a vacuum system component VSC. In at least some embodiments, the power supply unit 31 may be removed, leaving the ionization vacuum pressure sensor 3 and base 9 in place on the vacuum system component VSC.

[0084] Now refer to Fig.12 and 13 The application of electrical potting compound 83 to a power supply unit 31 is described. It is contemplated that the process will be performed simultaneously on multiple power supply units 31. However, for the sake of brevity, the process is described herein with reference to a single power supply unit 31.

[0085] The electrical components of the power supply unit 31 (including the transformer 37) and the daughter board 65 are surface mounted to the motherboard 55 to form a subassembly 121. An electrical potting compound 83 is applied to the subassembly 121. In particular, the subassembly 121 is supported in a mold tool 125 that defines a mold cavity 123. In the present embodiment, the mold tool 125 includes an annular wall 127 that forms a side wall of the mold cavity 123. The mold tool 125 in the present embodiment is configured to close or cover each first electrical connector 41-n so as to prevent the electrical potting compound 83 from contaminating the contact surface. In the present embodiment, the mold tool 125 includes a plurality of mold recesses 129 that are configured to receive the ends of the first electrical connectors 41-n. The first electrical connectors 41-n are positioned in the mold recesses 129, thereby allowing the first surface 67A of the daughter board 65 to contact the base of the mold cavity 123 in a face-to-face arrangement. The distal ends of the first electrical connectors 41-n may rest against the base or mold recess 129 of the mold cavity 123, preferably sealing each first electrical connector 41-n. Alternatively or additionally, the mold cavity 123 may include one or more protrusions (not shown) for positioning in the first electrical connectors 41-n. A release agent may be provided in the mold cavity 123 to facilitate removal of the power supply unit 31 after the electrical potting compound 83 has cured.

[0086] The subassembly 121 is positioned in the mold tool 125 such that an outer portion of the first surface 57A of the mother plate 55 rests on the annular wall 127. The mother plate 55 at least substantially seals the mold cavity 123. The first surface 57A of the mother plate 55 faces into the mold cavity 123. A closing member 131 is mounted to the mold tool 125 to secure the subassembly 121 in place. The closing member 131 includes an annular protrusion 133 for engaging the second surface 57B of the mother plate 55. A seal is formed between the mother plate 55 and the mold tool 125 and / or the closing member 131 to at least substantially seal the mold cavity 123. The seal may be formed between the outer edge of the mother plate 55 and the sidewall of the mold cavity 123. Alternatively or additionally, a seal may be formed between the second surface 57B of the mother plate 55 and the annular protrusion 133 of the closing member 131.

[0087] An electrical potting compound 83 is injected into the mold cavity 123 to at least partially encapsulate the daughter board 65. The electrical potting compound 83 is provided around the perimeter of the daughter board 65. The depth of the electrical potting compound 83 (from the first surface 57A of the mother board 55) can be less than the thickness of the daughter board 65. However, preferably, the depth of the electrical potting compound 83 is substantially equal to or greater than the thickness of the daughter board 65. The electrical potting compound 83 can form a thin layer on the first surface 67A of the daughter board 65. The electrical potting compound 83 fills the mold cavity 123 and encapsulates the electrical components provided on the first surface 57A of the mother board 55. In the present embodiment, the electrical potting compound 83 is introduced under vacuum to enhance penetration. The mold recess 129 formed in the mold tool 125 prevents the electrical potting compound 83 from entering the first electrical connector 41-n.

[0088] The electrical potting compound 83 is cured in the mold cavity 123. The closing member 131 is removed, and the power supply unit 31 is removed. The power supply unit 31 is then installed in the vacuum pressure gauge 1.

[0089] like Fig.12 As shown, the mold tool 125 includes a plurality of mold cavities 123. In use, a plurality of subassemblies 121 are mounted in the mold tool 125, and the electrical potting compound 83 is introduced into the mold cavities 123 simultaneously. Fig.13 As shown, multiple mold tools 125 can be processed simultaneously. A fixture 135 is provided for supporting multiple mold tools 125.

[0090] It will be appreciated that various changes and modifications may be made to the present invention without departing from the scope of the present application. The power supply unit 31 and the control unit 35 in the present embodiment have been described as being arranged on a separate printed circuit board (PCB). In a variation, the power supply unit 31 and the control unit 35 may be arranged on the same printed circuit board (PCB).

[0091] Reference numerals

[0092]

[0093]

Claims

1. A power supply unit (31) configured to be integrated into a vacuum pressure gauge, the vacuum pressure gauge (1) comprising an ionization vacuum pressure sensor (3) having an anode (7) and a cathode (9); wherein: The power supply unit (31) comprises: a motherboard (55) comprising a first surface (57A) and a second surface (57B), wherein a transformer (37) having a primary coil (W1) and a secondary coil (W2) is mounted to the motherboard (55); and a daughterboard (65) comprising one or more first electrical connectors (41-n) for supplying power to the ionization vacuum pressure sensor (3), the one or more first electrical connectors (41-n) comprising a high voltage (HV) first electrical connector (41-1) electrically connected to the secondary coil (W2) of the transformer (37), the high voltage (HV) first electrical connector (41-1) being configured to be connected to an anode (7) of the ionization vacuum pressure sensor (3); The daughter board (65) includes a first surface (67A) and a second surface (67B), and the daughter board (65) is mounted to the first surface of the mother board (55) so that the second surface of the daughter board (65) is arranged adjacent to the first surface (57A) of the mother board (55), and one or more first electrical connectors (41-n) on the daughter board (65) are arranged on the first surface (67A) of the daughter board (65) and are spaced apart from the first surface of the mother board (55).

2. The power supply unit (31) according to claim 1, wherein: The daughter board (65) is surface mounted to the first surface (57A) of the mother board (55).

3. The power supply unit (31) according to claim 1, wherein: The motherboard (55) comprises at least one control interface connector (59-1, 59-2) for connecting to a control unit, and the at least one control interface connector (59-1, 59-2) is mounted on a second surface of the motherboard (55).

4. The power supply unit (31) according to any one of claims 1, 2 or 3, wherein: The one or more first electrical connectors (41-n) each include a socket for receiving a connector pin to establish an electrical connection.

5. The power supply unit (31) according to claim 4, wherein: The or each socket comprises a central axis (Xn) extending substantially perpendicularly to the first surface (57A) of the motherboard (55).

6. The power supply unit (31) according to any one of the preceding claims, wherein: At least one channel (79) is formed in the surface of the daughter board (65) to form a space between the mother board (55) and the daughter board (65); the space between the mother board (55) and the daughter board (65) is optionally filled with an electrical potting compound.

7. The power supply unit (31) according to any one of the preceding claims, wherein: The daughterboard (65) includes a plurality of first electrical connectors (41-n), the daughterboard (65) including a cut-out portion (81) formed between first and second ones of the first electrical connectors (41-n); the cut-out portion is optionally filled with an electrical potting compound.

8. The power supply unit (31) according to any one of the preceding claims, wherein: An aperture (73) is formed in the motherboard (55), and the transformer (37) is disposed in the aperture (73).

9. The power supply unit (31) according to any one of the preceding claims, wherein: At least a portion of the first surface (57A) of the motherboard (55) and at least a portion of the daughterboard (65) are encapsulated in an electrical potting compound (83); the first electrical connector (41-n) is not obstructed by the electrical potting compound (83).

10. The power supply unit (31) according to claim 9, wherein: The electrical potting compound (83) is disposed on at least a portion of the first surface (67A) of the daughterboard (65).

11. The power supply unit (31) according to claim 9 or claim 10, wherein: The electrical potting compound (83) is disposed around the outer circumference of the daughter board (65).

12. A power supply unit (31) according to any one of claims 9 to 11, when directly or indirectly dependent on claim 6, wherein: The at least one channel (79) formed in the daughterboard (65) is at least substantially filled with an electrical potting compound (83).

13. A power supply unit (31) according to any one of claims 9 to 11, when directly or indirectly dependent on claim 7, wherein: The cut-away portion (81) is at least substantially filled with the electrical potting compound.

14. A vacuum pressure gauge (1) comprising a power supply unit (31) according to any one of the preceding claims.

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