Plug connection part for inductively transmitting energy and / or signals in an explosive environment, connection device, and measuring system

Abstract

A plug connection part (4) for inductively transmitting energy and / or signals in an explosive environment, in particular for a measuring system (1), comprises: an electrical circuit (28) having a circuit terminal (29) for supplying the plug connection part (4) with electrical energy; a primary coil (23) in the circuit (28), for inductively coupling to a secondary coil (11); and an ignition suppression means (39) in the circuit (28), for preventing an ignition effect in the event of a fault by limiting a retroactive effect of the electrical energy on the circuit terminal (29). A connection device (2) for inductively transmitting energy and / or signals comprises a plug connection part (4) of this type, and a measuring system comprises a connection device (2) of this type.

Description

[0001] Plug-in connector for inductive transmission of energy and / or signals in a potentially explosive environment, connecting device and measuring system

[0002] The content of the German patent application DE 10 2023 204 576.1 is incorporated herein by reference.

[0003] The invention relates to a plug-in connector for the inductive transmission of energy and / or signals in potentially explosive environments, particularly for a measuring system. Furthermore, the invention relates to a connection device for the inductive transmission of energy and / or signals. The invention also relates to a measuring system.

[0004] DE 10 2018 122 015 A1 discloses an inductive interface for the inductive transmission of signals between a primary side and a secondary side. The inductive interface establishes a detachable signal connection between a higher-level unit and a field device. To ensure the suitability of the field device for use in potentially explosive environments while keeping its dimensions as small as possible, an assembly circuit for preventing sparking is arranged on a circuit carrier carrying the secondary coil. There is a continuing need for an inductive plug-in connection that is particularly robust in terms of signal transmission and can be operated particularly safely in potentially explosive environments.

[0005] DE 197 19 730 CI discloses a plug connection for the inductive transmission of power and signals in potentially explosive environments, with limiting devices designed to prevent ignition in the event of a fault. The limiting devices are designed to provide ignition protection in the area of ​​the plug connection and in the area of ​​secondary-side sensors and actuators. A disadvantage is that the ignition risk posed by the electrical energy absorbed via a voltage source-side circuit connection on the circuit connection is not reduced.

[0006] It is an object of the invention to provide an improved plug connection part for the inductive transmission of energy and / or signals in an explosive environment, which in particular can be operated particularly safely in such an environment and ensures the energy and / or signal transmission in a particularly reliable and robust manner.

[0007] This object is achieved by a plug-in connector having the features of claim 1. It has been recognized that a plug-in connector for inductively transmitting energy and / or signals in a potentially explosive environment, in particular for a measuring system, having a circuit connection for supplying the plug-in connector with electrical energy and a primary coil, can have an ignition suppression means designed to prevent an ignition effect, particularly in the event of a fault, by limiting the reaction of the electrical energy to the circuit connection. This makes the plug-in connector particularly safe to operate, particularly in a potentially explosive environment.By arranging the ignition suppression means on the primary-side plug-in connector, particularly with regard to the inductive transmission point on the plug-in connector located on the side of a power source, the inductive energy and / or signal transmission can be designed to be particularly robust without compromising suitability for the potentially explosive environment. Rather, by designing the plug-in connector with the ignition suppression means, the ignition suppression effect can be improved, even if the plug-in connector has a means for promoting particularly robust energy and / or signal transmission. The inductive energy and signal transmission can thus be ensured to be particularly robust against external interference, for example electromagnetic fields, and / or against mechanical influences, in particular contamination.Thanks to the ignition suppression means, the connector part, in particular a device and / or a measuring system formed therewith, can be designed to be so safe that a complex spark test for experimental proof of explosion safety can be avoided. Such a connector part can thus be provided in a particularly cost-effective manner for use in potentially explosive environments.

[0008] Signals can generally have a non-negligible energy component. The ignition suppression means, for the purposes of explosion protection, preferably also acts on this energy component, in particular on any electrical energy present in the plug-in connection part. In other words, the ignition suppression means can be designed to prevent an ignition effect in the event of a fault by limiting the reaction of electrical energy, in particular energy and / or signals, to the circuit connection. Signals can be used to transmit analog and digital information, for example enabling data transmission. Instead of diodes, other integrated or non-integrated components with a diode-like function can also be used. For example, so-called shunt voltage regulators or other components with a non-linear characteristic curve and suitable threshold orBreakdown voltages.

[0009] Preferably, the circuit terminal, the primary coil, and / or the ignition suppression means are integrated into the electrical circuit, in particular arranged at least partially, in particular predominantly, on the same circuit board, in particular a single- or multi-layer circuit board, and / or arranged at least partially, in particular completely, in the same housing of the plug-in connection part. The circuit terminal and / or the primary coil and / or the ignition suppression means are preferably integrally connected to one another, in particular by means of a soldered connection.

[0010] The connector part is preferably designed to be intrinsically safe in terms of explosion protection, particularly electrical ignition protection. The connector part is preferably intrinsically safe for operation in a gas explosion protection zone and / or in a dust explosion protection zone, in particular at least Category 2, in particular at least Category 1, in particular Category 0. For this purpose, the energy that can be stored in the connector part is preferably limited to a safe level.

[0011] The fault may include at least one electrical line, in particular for conducting energy and / or signals, in particular electrical power, in particular a signal, a supply potential and / or a reference potential line, being interrupted, in particular unintentionally and / or contrary to operating instructions, and / or an electrical connection, for example a short circuit, being established unintentionally, in particular in this order or vice versa, for example due to damage, in particular mechanical damage. For example, any short-circuiting and / or opening of the electrical line, in particular a faulty solder joint, a broken cable, liquid, in particular electrically conductive liquid, penetrating the circuit, and / or improper loosening of the plug connection, can lead to such a fault.

[0012] The transmission of energy and / or signals can be understood as the transmission of electrical energy, in particular power, and / or the transmission of information, in particular an electrical signal. The transmitted electrical power can be used, for example, to supply an electrical consumer, in particular a data processing means and / or a sensor. The transmission of energy and / or signals preferably takes place between the primary coil and a secondary coil, in particular in both directions and / or from the primary coil to the secondary coil and / or from the secondary coil to the primary coil. Electrical power is preferably transmitted from the primary coil to the secondary coil, in particular for operating a secondary-side circuit, in particular the mating plug-in connection part and / or at least one sensor.The data exchange can take place in both directions, preferably at least from the secondary coil to the primary coil.

[0013] The plug-in connection part is preferably the connection part located on the primary side of the inductive transmission point, in particular on the side of a power source. The plug-in connection part is designed, in particular, for detachable connection, in particular for non-destructive detachment, to a mating plug-in connection part. A closure means, in particular for forming a bayonet closure, is preferably provided for reversibly securing the plug-in connection.

[0014] The circuit connection is designed to exchange electrical power and / or electrical signals with the plug-in connection part. A signal processing device, in particular designed separately from the plug-in connection part and arranged at a distance therefrom, is preferably in signal communication with the circuit connection. The signal processing device is also referred to as a transmitter. The signal processing device preferably serves as a power source for the plug-in connection part. The circuit connection can comprise electrical contacts, in particular solder contacts and / or clamp contacts. The circuit connection is preferably designed to connect the circuit to a connecting cable, in particular to the signal processing device.The circuit connection can have power supply contacts, in particular at least one operating voltage contact and / or a reference potential contact, and / or at least one, in particular at least two, signal line contacts, in particular data contacts, in particular data bus contacts. The at least one operating voltage contact is also referred to as a supply potential contact, and the at least one operating voltage is also referred to as a supply potential. An ignition effect can result from an ignition spark, in particular if this is not shielded from the potentially explosive environment. An ignition effect can also potentially arise if the surface of an object exceeds a certain temperature. Preferably, the ignition suppression means counteracts at least one, in particular all two, ignition mechanisms.

[0015] The ignition suppression means preferably comprises an electrical and / or electronic component, in particular for limiting the maximum electrical energy and / or power that can be transmitted from the circuit to the circuit terminal and / or the maximum voltage that can be applied between any two contacts of the circuit terminal. The ignition suppression means is preferably electrically contacted in the circuit between the primary coil and the circuit terminal, in particular directly connected to the circuit terminal.

[0016] The direct electrical connection of a first object to a second object is understood in particular to mean that along the electrical connection between the first object and the second object, at most line resistances, in particular line resistances of a maximum of 1 ohm, in particular a maximum of 100 ohms, in particular a maximum of 1 kOhm, but no further components, in particular no resistors and / or no capacitors and / or no inductances and / or no control elements, are arranged.

[0017] Limiting the feedback of electrical energy to the circuit connection means, in particular, limiting the maximum possible return flow of energy, in particular per unit of time, i.e., the maximum electrical power, to the circuit connection and / or limiting the maximum electrical voltage that can be transmitted from the plug connection, in particular the circuit, to the circuit connection. The energy is, in particular, the energy that is absorbed by the plug connection part via the circuit connection and / or stored by the plug connection part, at least temporarily.

[0018] According to one aspect of the invention, the plug connection part has an encapsulation, in particular a potting compound. The electrical circuit is preferably encapsulated, in particular housed and / or potted, at least in sections, in particular completely, in particular in a liquid-tight and / or gas-tight manner. The potting compound can comprise, in particular consist of, an electrically insulating material, in particular a plastic material. The potting compound can be thermally conductive for heat dissipation from the circuit. The plug connection part, in particular the electrical circuit, and / or a connecting cable, can have electrically and / or magnetically effective shielding.

[0019] The plug-in connector is preferably a component of a measuring system with a sensor for detecting a measured variable. The plug-in connector can be arranged opposite the sensor in terms of a power supply and / or in terms of the inductive transmission point.

[0020] According to one aspect of the invention, the circuit can have an amplifier device, in particular for amplifying an electrical signal supplied to the primary coil and / or received by the primary coil. The amplifier device preferably has at least one inductive component and / or a capacitive component and / or a component for at least temporarily storing electrically supplied, in particular electrical and / or magnetic, energy. The inductive component can have an electrical inductance of at least 0.1 mH, in particular at least 0.5 mH, in particular at least 1 mH, in particular at least 10 mH, and / or a maximum of 100 mH, in particular a maximum of 10 mH. The capacitive component can have an electrical capacitance of at least 1 pF, in particular at least 10 pF, in particular at least 100 pF, and / or a maximum of 1 mF, in particular a maximum of 100 pF.The amplifier device, in particular the at least one inductive and / or capacitive component, can, in particular when used as intended, in particular when operated with a predetermined operating voltage, have an energy storage capacity of at least 1 pJ, in particular at least 10 pJ, in particular at least 50 pJ, in particular at least 100 pJ, in particular at least 200 pJ, in particular at least 400 pJ, and / or a maximum of 100 mJ, in particular a maximum of 50 mJ, in particular a maximum of 10 mJ, in particular a maximum of 1 mJ, in particular a maximum of 500 pJ, in particular a maximum of 500 pJ. In particular, the plug-in connection part, in particular the electrical circuit, in particular the amplifier device, can have a total inductance and / or a total capacitance and / or a total energy storage capacity according to at least one of the above ranges.

[0021] The amplifier device can have an electrical resonant circuit, in particular a series resonant circuit and / or a parallel resonant circuit, in particular comprising the at least one inductive element and the at least one capacitive element. Preferably, the primary coil is a component of the electrical resonant circuit. Preferably, the amplifier device comprises a Class E amplifier, in particular it consists thereof. The amplifier device advantageously ensures that signals, in particular data signals, can be transmitted particularly reliably and robustly via the inductive connection. However, the amplifier device increases the energy storage capacity of the circuit. The ignition suppression means can be designed to limit any possible reaction of the electrical energy stored in the amplifier device to the circuit connection.

[0022] The amplifier device can have a supply inductance connected upstream of the electrical resonant circuit. For energy-efficient operation of the resonant circuit, the electrical inductance of the supply inductance must be sufficiently high. This increases the energy storage capacity of the circuit, particularly of the amplifier device. The ignition suppression means limits the potential impact of the electrical energy stored in the supply inductance on the circuit terminal.

[0023] According to one aspect of the invention, the amplifier device has a total electrical inductance of at least 0.1 mH, in particular at least 0.5 mH, in particular at least 1 mH, in particular at least 5 mH. The total electrical inductance of the amplifier device preferably comprises at least the electrical inductance of the supply inductance and / or the electrical inductance of the primary coil.

[0024] According to a further aspect of the invention, the ignition suppression means is arranged between the amplifier device and the circuit terminal, in particular electrically contacted. The ignition suppression means can be electrically connected in parallel to the amplifier device, in particular between a supply potential contact and a reference potential contact of the circuit terminal, in particular with electrical contact between the amplifier device and the circuit terminal, or in series to the amplifier device, in particular between the supply potential contact or the reference potential contact and the amplifier device.

[0025] The ignition suppression means can electrically contact the operating voltage contact and / or a reference potential contact of the circuit terminal, in particular directly.

[0026] According to a further aspect of the invention, the plug-in connection part has a current conditioning device in the circuit, in particular along the electrical line between the circuit terminal and the ignition suppression means. The current conditioning means can comprise a voltage smoothing element and / or a voltage regulator and / or a voltage divider. The current conditioning means can be designed to provide at least one, in particular at least two, voltage levels for operating the plug-in connection part.Preferably, the ignition suppression means is electrically contacted along the electrical line between the power conditioning device and the primary coil, in particular the amplifier device, in particular in a series circuit, in particular between the supply potential contact or the reference potential contact and the power conditioning device and / or to the amplifier device, and / or a parallel circuit, in particular between a supply potential contact and a reference potential contact, to the power conditioning device and / or to the amplifier device, in particular to the primary coil. The plug-in connection part can have further modules, in particular a communication device, in particular a digital module and / or a modem module and / or a modulator / demodulator module and / or a frequency filter, in particular a bandpass filter.

[0027] According to a further aspect of the invention, the ignition suppression means is connected directly to the circuit terminal. As a result, the ignition suppression means limits the reaction of the electrical energy to the circuit terminal particularly reliably.

[0028] According to a further aspect of the invention, the plug-in connection part can have a connecting cable at the circuit connection. The ignition suppression means can be designed to limit a reaction of the electrical energy to the connecting cable, in particular to prevent an ignition effect in the connecting cable, in particular in the event of a fault, in particular a contact fault and / or a line fault, for example a short circuit or a cable break. The connecting cable can have shielding. The connecting cable preferably comprises at least two, in particular at least three, in particular at least four, cable cores. The connecting cable, in particular the cable cores, are connected to the circuit connection, in particular corresponding connection contacts, preferably in a force-fitting and / or material-fitting manner.The shield can also be non-positively and / or materially connected to the housing and / or an additional and / or existing contact of the circuit connection. The connecting cable is preferably arranged at least partially, in particular largely, outside a housing of the plug-in connection part. According to one aspect of the invention, the ignition suppression means can be designed to limit electrical energy and / or power potentially contributing to the ignition of an explosive composition in the potentially explosive environment. The ignition suppression means can comprise at least one electrical resistor for the controlled dissipation of energy, in particular energy stored in the circuit, in particular in the amplifier device, in particular in the supply inductance. The ignition suppression means can have a voltage limiter and / or a power limiter, in particular a power regulator.The ignition suppression means may comprise a short-circuit element, for example a crowbar and / or a voltage limiter, in particular a shunt voltage limiter, which is arranged in particular in a parallel circuit to an energy-storing assembly of the plug connection part, for example in a parallel circuit to the amplifier device, in particular to the supply inductance and / or to the primary coil.

[0029] According to one aspect of the invention, the ignition suppression means comprises at least one diode, which is connected directly to the circuit terminal, in particular to the reference potential contact and / or the operating voltage contact, in particular for limiting a maximum connection voltage. The at least one diode can be a rectifier diode, in particular a silicon diode, and / or a Schottky diode and / or a Zener diode, hereinafter also referred to as a Zener diode. A forward voltage of the diode is preferably in a range from 0.1 V to 10 V, in particular from 0.2 V to 5 V, in particular from 0.3 V to 2 V. A breakdown voltage, in particular of the Zener diode, is preferably in a range from 1 V to 30 V, in particular from 1.5 V to 10 V, in particular from 2 V to 7 V, in particular from 3 V to 6 V.Preferably, the ignition suppression means comprises a bidirectional short-circuit element, in particular for limiting the level of an energy and / or voltage input that can potentially be effected by the resonant circuit to the circuit terminal.

[0030] The at least one diode preferably limits a maximum electrical voltage that can be produced between at least two, in particular all, connection contacts of the circuit connection.

[0031] According to one aspect of the invention, the ignition suppression means can comprise at least two of the diodes, in particular between two power supply contacts of the circuit terminal. The at least two diodes are preferably connected directly to the power supply contacts, in particular to the operating voltage contact and / or to the reference potential contact, in particular in a parallel circuit to one another and / or to the amplifier device and / or to the power conditioning device. The at least two diodes are preferably rectifier diodes, in particular Schottky diodes. The forward direction of the at least two diodes is preferably oriented from the reference potential contact to the operating voltage contact.

[0032] The ignition suppression means can be configured with single or multiple redundancy, in particular at least two, in particular at least three. For this purpose, the at least two, in particular at least three, diodes can be connected in parallel.

[0033] According to one aspect of the invention, the ignition suppression means can have at least one, in particular at least two, in particular exactly two, diodes, in particular rectifier diodes, in particular Schottky diodes, between the operating voltage contact and the first signal line contact and / or between the first signal line contact and the reference potential contact and / or between the operating voltage contact and the second signal line contact and / or between the second signal line contact and the reference potential contact. Preferably, the respective diode is directly connected to the respective contact. The design of the ignition suppression means with the at least two rectifier diodes preferably leads to redundancy, in particular at least twofold, for example when the diodes are connected in parallel, and thus to particularly reliable ignition suppression.It is also possible to design the ignition suppression means with a single diode, without redundancy, or with a higher number of redundancy, in particular at least twice, in particular at least three times.

[0034] According to one aspect of the invention, the ignition suppression means comprises at least two Zener diodes between two power supply contacts of the circuit terminal, in particular between the operating voltage contact and the reference potential contact. The at least two Zener diodes are preferably directly electrically connected to the power supply contacts. For at least threefold redundancy, the number of Zener diodes can be increased accordingly. A design with a single Zener diode is alternatively possible to avoid redundancy.

[0035] According to one aspect of the invention, the ignition suppression means may comprise at least one diode and / or at least one resistor.

[0036] The power conditioning device can be electrically connected between the power conditioning device and the operating voltage contact, particularly in the signal line direction. The ignition suppression means is preferably connected in series with the power conditioning device. The ignition suppression means can be connected in parallel with the amplifier device, particularly with the primary coil. A terminal of the ignition suppression means preferably contacts an electrical line between the power conditioning device and the primary coil, particularly with the amplifier device.

[0037] According to one aspect of the invention, the plug-in connector, in particular the electrical circuit, can have an energy storage capacity that exceeds an ignitability limit during intended use of the plug-in connector. In particular, an ignitability limit would be exceeded without the ignition suppression agent. During intended use, the plug-in connector is operated with a, in particular maximum, permissible operating voltage. The operating voltage of the plug-in connector is preferably in a range from 1 V to 30 V, in particular from 1.5 V to 25 V, in particular from 2 V to 12 V, in particular from 2.25 V to 8 V, in particular from 2.5 V to 4 V, preferably 3 V.The energy storage capacity of the plug-in connection part, in particular of the circuit during intended use, in particular the inductive and / or capacitive energy storage capacity, is preferably in a range from 1 pJ to 500 mJ, in particular from 5 pJ to 100 mJ, in particular from 10 pJ to 1 mJ, in particular from 20 pJ to 500 pJ, in particular from 40 pJ to 200 pJ. A further object of the invention is to provide an improved connection device for the inductive transmission of energy and / or signals, which can be operated safely in an explosive environment and ensures the energy and / or signal transmission in a particularly reliable and robust manner.

[0038] This object is achieved by a connecting device for the inductive transmission of energy and / or signals, in particular electrical power and / or signals, comprising a plug-in connection part according to the above description and a mating plug-in connection part for reversibly detachable connection to the plug-in connection part. The advantages of the connecting device correspond to the advantages of the plug-in connection part. The connecting device is preferably further developed with at least one of the features described above in connection with the plug-in connection part.

[0039] Preferably, the mating connector part has a secondary circuit in which the secondary coil is arranged. The mating connector part can have an ignition suppression means in the secondary circuit for preventing an ignition effect in the event of a fault, in particular for limiting a reaction of the electrical energy received by the mating connector part to the connector part, in particular to the primary coil.

[0040] The connection device preferably has a locking means for reversibly releasably locking the plug connection between the plug connection part and the mating plug connection part. The locking means can be designed as a snap-in connection and / or a bayonet connection. The locking means preferably comprises a locking sleeve, in particular one that is rotatable about a central longitudinal axis of the connection device.

[0041] The connection device is preferably designed to be intrinsically safe with regard to electrical explosion protection, in particular suitable for safe operation in an explosive environment.

[0042] A further object of the invention is to provide an improved measuring system which can be operated particularly safely in an explosive environment and ensures the transmission of sensor signals in a particularly reliable and robust manner.

[0043] This object is achieved by a measuring system comprising at least one sensor and a connecting device as described above. The at least one sensor can comprise a pH sensor and / or a temperature sensor and / or a pressure sensor and / or a humidity sensor and / or a redox sensor and / or an oxygen sensor and / or a conductivity sensor and / or a liquid sensor and / or a gas sensor.

[0044] The at least one sensor is preferably connected to the mating connector part in a signal-transmitting and / or mechanical, in particular rigid, manner. The at least one sensor can be attached to a housing, in particular the secondary housing, of the mating connector part. The at least one sensor is preferably attached to the mating connector part by means of a cable or directly, in particular wirelessly. The measuring system can have at least two, in particular at least three, in particular at least four of the sensors, in particular arranged on the same mating connector part.

[0045] The sensor signals detected by the at least one sensor are preferably transmitted inductively, in particular via the inductive coupling path of the primary coil and the secondary coil, between the mating connector part and the connector part. Energy and / or signals are preferably transmitted via this inductive coupling path. In particular, the energy supply to the at least one sensor is provided via this inductive coupling path.

[0046] According to one aspect of the invention, the measuring system can comprise a signal processing device for processing the sensor signals transmitted by the connection device. The signal processing device can provide electrical energy to supply the plug-in connection part and / or the mating plug-in connection part and / or the at least one sensor, in particular acting as an energy source for these. Preferably, the signal processing device provides an operating voltage between the operating voltage contact and the reference potential contact.

[0047] The signal processing device is preferably connected to the plug connection part by means of the connecting cable.

[0048] The signal processing device can have a user interface, in particular for input and / or output of information, in particular an output unit, in particular a display and / or a loudspeaker and / or an input unit, in particular at least one touch- and / or pressure-sensitive element.

[0049] The signal processing device can comprise a data transmission unit for wired or wireless data transmission, in particular a LAN interface and / or a radio interface and / or a Wi-Fi interface. The signal processing device is preferably in signal communication with a central processing unit, in particular a control room. The signal processing device can comprise at least one electronic processing unit, in particular a processor, in particular a microcontroller, for processing the sensor signals.

[0050] According to one aspect of the invention, the signal processing device is designed to be intrinsically safe with regard to explosion protection. The signal processing device can have an ignition suppression means for preventing an ignition effect in the event of a fault, in particular by limiting the maximum electrical energy that can be applied to the connecting device, in particular to the plug-in connector and / or the connecting cable, in particular per unit time and / or voltage.

[0051] Because the connector part has the ignition suppression device, an ignition effect can be reliably prevented in the event of a fault, regardless of whether the connection cable is intact. This applies in particular if a sufficient amount of energy for the ignition effect can be stored, in particular is stored, in the connector part. Particularly safe operation of the measuring system in the potentially explosive environment can be achieved in particular by further designing the measuring system and the mating connector part to be intrinsically safe, in particular with an ignition suppression device.

[0052] Further features, details, and advantages of the invention will become apparent from the following description of several embodiments with reference to the figures. They show:

[0053] Fig. 1 A perspective, partially sectioned view of a measuring system with a connection device for the inductive transmission of energy and / or signals, comprising a plug connection part with an ignition suppression means for preventing an ignition effect in the event of a fault and a counter plug connection part,

[0054] Fig. 2 is a schematic representation of the connection device in Fig. 1 with the plug connection part and the counter-plug connection part,

[0055] Fig. 3 is a schematic diagram of the mating connector part in Fig. 1 with a sensor circuit connection for forming a signal connection with a sensor and a secondary coil for inductive coupling with the connector part, in particular a primary coil of the connector part,

[0056] Fig. 4 a schematic diagram of the connector part in the

[0057] Fig. 1 according to a first embodiment, wherein the ignition suppression means comprises ten diodes, in particular two Zener diodes and eight Schottky diodes, or

[0058] Fig. 5 is a schematic diagram of a plug connection part according to a further embodiment, wherein the ignition suppression means comprises two diodes, in particular two Schottky diodes, and a resistor, which are contacted in an electrical circuit between an amplifier device and a current conditioning device of the plug connection part.

[0059] A first embodiment of a measuring system 1 with a connection device 2 and a sensor 3 connected thereto is described with reference to Figs. 1 to 4.

[0060] Sensor 3 is designed as a pH sensor. Sensor 3 can alternatively or additionally be designed as a redox sensor, a conductivity sensor, an oxygen sensor, a temperature sensor, a pressure sensor, and / or a sensor for other process-related parameters. The sensor can have an optical, an inductive, and / or an electrode-based measuring device.

[0061] The connection device 2 comprises a plug-in connector part 4 and a mating plug-in connector part 5 that can be reversibly connected thereto. The sensor 3 is preferably rigidly connected to the mating plug-in connector part 5, in particular to a housing 6 of the mating plug-in connector part 5.

[0062] The housing 6 of the mating connector part 5 has a thread 7, in particular an external thread. The thread 7 is designed for fastening the mating connector part 5 to a measuring point. The thread 7 is designed in particular such that the mating connector part 5 can be attached to a measuring chamber wall such that the sensor 3 is arranged in the measuring chamber and the mating connector part 5 is arranged at least partially outside the measuring chamber. The measuring chamber wall is sealed by the mating connector part 5, in particular a sealing element, preferably in a fluid-tight, in particular gas-tight manner. The housing 6 of the mating connector part 5 has a tool engagement 8 for rotating the mating connector part 5, in particular for screwing the thread 7 to the measuring chamber wall.

[0063] The mating connector part 5 is described in further detail with reference to Figs. 1 to 3. The mating connector part 5 comprises an electrical secondary circuit 9, which is preferably formed at least partially, in particular predominantly, on a secondary circuit board 10. A secondary coil 11 is arranged in the secondary circuit 9. The secondary coil 11 is a component of an inductive coupling path for the transformer-based transmission of energy and / or signals.

[0064] The secondary coil 11 is wound on a secondary coil body 12, in particular a hollow cylindrical one. A central recess 13 of the secondary coil body 12 is cylindrical.

[0065] The secondary circuit 9 has a sensor circuit connection 14 for establishing a power and / or signal-transmitting connection with the sensor 3. The sensor circuit connection 14 is designed to supply the sensor 3 with power and to transmit sensor signals. For this purpose, the sensor circuit connection 14 comprises a plurality of, in particular at least three, in particular at least four, connection contacts, which are preferably connected to a corresponding mating connection contact of the sensor 3, in particular integrally connected, in particular soldered.

[0066] The secondary circuit 9 preferably further comprises at least one of the following devices: a secondary power conditioning device 15 for providing at least one supply voltage, in particular at least two supply voltages, and / or a secondary rectifier device 16 for rectifying an alternating voltage induced at the secondary coil 11 and / or a secondary communication device 17, in particular a modulator / demodulator module and / or a modem module, for exchanging energy and / or signals via the secondary coil 11 and / or a sensor communication device 18 for exchanging data with the sensor 3 and / or a sensor signal conditioning device 19, in particular with an analog-to-digital converter, for conditioning the sensor signals. The sensor communication device 18 can be a component of a digital module for processing digital data.

[0067] The mating connector part 5, in particular the secondary power conditioning device 15 and / or the secondary rectifier device 16, can have a secondary ignition suppression means 20.1, 20.2 for preventing an ignition effect in the event of a fault by limiting a maximum electrical power that can be transmitted to the secondary coil 11 and / or the sensor circuit connection 14.

[0068] For the mechanical connection of the plug-in connector part 4 with the mating plug-in connector part 5, these parts interact in the manner of a plug connection. A reversibly detachable closure means 5a, in particular a bayonet lock, prevents the plug connection from being released, particularly accidentally.

[0069] The measuring system 1 and the plug-in connection part 4 are described in further detail with reference to Figs. 1, 2 and 4. The plug-in connection part 4 has a housing 21. A cylindrical projection 22 is arranged on the housing 21 and is designed to engage in the cylindrical recess 13 of the mating plug-in connection part 5, in particular the housing 6 of the mating plug-in connection part 5. A primary coil 23 of the plug-in connection part 4 is arranged in the cylindrical projection 22 and is inductively coupled to the secondary coil 11 when the plug-in connection part 4 is in engagement with the mating plug-in connection part 5, in particular when the cylindrical projection 22 is in engagement with the recess 13.

[0070] A connecting cable 24 is provided on the plug-in connector 4. The connecting cable 24 preferably establishes a signal connection to a signal processing device 25 of the measuring system 1. The connecting cable 24 is preferably firmly connected, in particular not detachable without damage, to the housing 21 of the plug-in connector 4. In particular, the connecting cable 24 can be connected to the housing 21 in a fluid-tight, in particular gas-tight, manner.

[0071] The signal processing device 25 is preferably designed to supply the connection device 2, in particular the plug-in connection part 4 and / or the mating plug-in connection part 5 and / or the sensor 3, with electrical energy and / or signals, in particular via the connecting cable 24. The signal processing device 25 is designed to exchange data, in particular to receive sensor signals and / or to transmit control signals, with the plug-in connection part 4. The signal processing device 25 can have a user interface 26 for inputting and outputting information, in particular with a display means for displaying information, in particular the sensor signals, and / or a communication module 27, in particular a radio module, for the wired and / or wireless exchange of data, in particular with a control room and / or a central computing system.

[0072] With reference to Fig. 4, the plug connection part 4 is described according to a first exemplary embodiment. The plug connection part 4 is designed for the inductive transmission of energy and / or signals, in particular electrical power and / or signals, in a potentially explosive environment. The plug connection part 4 has an electrical circuit 28 with a circuit terminal 29. The primary coil 23 is arranged in the circuit 28. The connecting cable 24 contacts the circuit terminal 29.

[0073] The circuit connection 29 comprises an operating voltage contact 29.1, a reference potential contact 29.2, a first signal line contact 29.3, and a second signal line contact 29.4. The reference potential contact 29.2 is also referred to as a ground contact, abbreviated GND. An operating voltage intended to supply power to the measuring system 1, in particular to the connection device 2, in particular to the plug-in connector part 4, is present between the operating voltage contact 29.1 and the reference potential contact 29.2. The operating voltage contact 29.1 and the reference potential contact 29.2 are also referred to as power supply contacts 29.1, 29.2. The plug-in connector part 4 comprises a power conditioning device 30 in the circuit 28. The power conditioning device 30 is connected, in particular directly connected, to the operating voltage contact 29.1 and the reference potential contact 29.2.The power conditioning device 30 can be designed to provide at least one, in particular at least two different, voltage levels.

[0074] The plug connection part 4 has a communication device 31, in particular a modulator-demodulator module and / or modem module, for exchanging energy and / or signals via the primary coil 23.

[0075] The plug connection part 4 can have a control device 32, in particular a digital module, in particular comprising an electronic processing unit. The control device 32 is designed to control the data transmission between the circuit connection 29 and the primary coil 23, in particular the communication device 31.

[0076] The plug connection part 4 has an amplifier device 33. The amplifier device 33 comprises an electrical resonant circuit 34. The resonant circuit 34 comprises the primary coil 23 and at least one capacitor 35.1, 35.2. Furthermore, the amplifier device 33 comprises a switch 36, in particular an electronic switch, in particular a transistor.

[0077] A supply inductance 37 is connected upstream of the resonant circuit 34. The supply inductance 37 is arranged along the electrical line between the power conditioning device 30 and the resonant circuit 34, in particular the switch 36, in particular is electrically contacted, in particular connected in series with them. The supply inductance 37 is designed such that the resonant circuit 34 is damped as little as possible by the supply inductance 37. For this purpose, the supply inductance 37 should be dimensioned as high as possible. However, in order to avoid efficiency losses as much as possible, the electrical resistance of the supply inductance 37 should also be reduced. Since the available installation space is limited, a preferred range results for the supply inductance 37 with regard to its electrical inductance, namely from 0.01 mH to 1 H, in particular from 0.1 mH to 100 mH, in particular from 1 mH to 10 mH, in particular from 3 mH to 7 mH.This applies in particular if a carrier signal frequency for switching the primary coil 23, which is generated in particular by means of the switch 36, lies in a range from 10 kHz to 10 MHz, in particular from 100 kHz to 1 MHz, in particular from 150 kHz to 400 kHz.

[0078] The switch 36 is in signal connection with the control device 32. The communication device 31 is in signal connection with the primary coil 23.

[0079] For voltage smoothing, a smoothing capacitor 38 can be connected to the circuit terminal 29, in particular to the operating voltage contact 29.1 and / or to the supply inductance 37, in particular on the side of the circuit terminal 29.

[0080] According to an alternative embodiment, the capacitor 38 may represent the total capacitance of the electrical circuit 28. According to this alternative, the capacitor 38 is not necessarily present in the form of a single component or at the position shown within the circuit 28.

[0081] The plug connection part 4 has an ignition suppression means 39 in the circuit 28 for preventing an ignition effect in the event of a fault by limiting a reaction of the electrical energy to the circuit connection 29. The ignition suppression means 39 is in particular directly connected to the circuit connection 29, in particular between the circuit connection 29 and the power conditioning device 30, electrically contacted.

[0082] The components of the circuit 28, in particular of the plug-in connection part 5, are preferably arranged at least partially, in particular predominantly, in particular completely, on at least one, in particular a single, primary circuit board 40. In particular, the ignition suppression means 39 and the amplifier device 33 are arranged on the primary circuit board 40.

[0083] The ignition suppression means 39 is preferably arranged between the operating voltage contact 29.1 and / or the reference potential contact 29.2, in particular in a parallel circuit to the amplifier device 33 and / or the current conditioning device 30.

[0084] The ignition suppression means 39 has at least four, in particular at least five, diodes 41.1, 42.1, 43.1, 44.1, 45.1, in particular rectifier diodes, in particular Schottky diodes. The first diode 41.1 is arranged between the operating voltage contact 29.1 and the first signal line contact 29.3. The second diode 42.1 is arranged between the first signal line contact 29.3 and the reference potential contact 29.2. The third diode 43.1 is arranged between the operating voltage contact

[0085] 29.1 and the second signal line contact 29.4. The fourth diode 44.1 is arranged between the second signal line contact 29.4 and the reference potential contact 29.2.

[0086] The ignition suppression means 39 preferably comprises a Zener diode 45.1 arranged between the operating voltage contact 29.1 and the reference potential contact 29.2.

[0087] Preferably, four additional diodes 41.2, 42.2, 43.2, 44.2, in particular rectifier diodes, in particular Schottky diodes, are provided, the respective arrangement of which corresponds to the arrangement of diodes 41.1, 42.1, 43.1, 44.1, whereby they complement these in pairs in a parallel circuit. A second Zener diode 45.2 can be arranged correspondingly to the first Zener diode 45.1 and complement it in pairs in a parallel circuit.

[0088] The above-described design of the ignition suppression means 39 with the paired arrangement of the diodes 41.1 to 45.1 and 41.2 to

[0089] 45.2 or the Zener diodes 45.1, 45.2 provide double redundancy. This redundancy is not mandatory. Multiple redundancy, in particular at least double redundancy, and in particular at least triple redundancy, ensures that the ignition suppression effect is particularly reliable.

[0090] The connecting cable 24 can be shielded. The plug-in connector part 4 and / or the mating plug-in connector part 5, in particular the circuit 28 and / or the secondary circuit 9, can be potted. In particular, the respective circuit 9, 28 can be potted in a fluid-tight, in particular gas-tight manner. The respective housing 6, 21 can be filled, in particular completely, with a potting compound. This particularly reliably prevents an ignition effect in the area of ​​the plug-in connector part 4 and / or the mating plug-in connector part 5.

[0091] The functioning of the measuring system 1, the connection device 2, the plug connection part 4 and the ignition suppression means 39 is as follows:

[0092] The plug-in connector part 4 is initially separated from the mating plug-in connector part 5. The thread 7 is screwed to the measuring chamber wall. The sensor 3 is designed as a pH sensor and is arranged in the measuring chamber, in particular at a measuring point. The mating plug-in connector part 5 is ready for reversible connection to the plug-in connector part 4.

[0093] For the inductive transmission of energy and / or signals between the plug-in connector part 4 and the mating plug-in connector part 5, these are plugged onto one another. The primary coil 23, in particular the cylindrical projection 22 of the housing 21 of the plug-in connector part 4, is inserted into the secondary coil 11, in particular into the recess 13 of the housing 6 of the mating plug-in connector part 5. The plug-in connection is locked by means of the locking means 5a. The plug-in connection forms a mechanical connection between the plug-in connector part 4 and the mating plug-in connector part 5. At the same time, the arrangement of the primary coil 23 in the secondary coil 11 establishes a connection for the inductive transmission of energy and / or signals via the circuit connection 29, in particular via the operating voltage contact 29.1 and the reference potential contact 29.2, the connecting device 2, in particular the plug-in connector part 4, is supplied with electrical energy. The electrical energy is preferably provided by the signal processing device 25 and conducted to the circuit terminal 29 via the connecting cable 24.

[0094] The signal processing device 25 is preferably designed to be intrinsically safe in the sense of explosion protection, in particular electrical ignition protection.

[0095] The plug connector part 4 has components that store electrical energy. The amplifier device 33, in particular the feed inductor 37 and the capacitors 35.1, 35.2, the primary coil 23, and the smoothing capacitor 38 act as electrical energy storage devices. The stored energy can exert an ignition effect in the event of a fault, which is particularly independent of the intrinsically safe design of the signal processing device 25. The potential ignition effect results in particular from the energy storage capacity of the amplifier device 33, in particular the feed inductor 37, which has a comparatively high electrical inductance for energy-efficient signal transmission.

[0096] In order to reliably prevent an ignition effect in the event of a fault, the potential reaction of the stored electrical energy to the circuit connection 29 is limited by means of the ignition suppression means 39. The ignition suppression means 39 prevents, in particular, that in the event of a break in the connecting cable 24 or if the connecting cable 24 is disconnected from a connection point, for example to the signal processing device,

[0097] 25, an ignition effect, in particular an ignition spark, occurs.

[0098] The ignition suppression means 39 ensures voltage limitation between two, preferably between all, of the contacts 29.1 to 29.4. This reliably prevents, in particular, an inductance, in particular the supply inductance 37, from causing a voltage sufficiently high for spark ignition at the circuit terminal 29, in particular between two contacts 29.1 to 29.4.

[0099] The pass band of the diodes 41.1 to 44.1, 41.2 to 44.2 can be in a range from 0 V to 10 V, in particular from 0.1 V to 5 V, in particular from 0.2 V to 2 V, in particular from 0.5 V to 1 V. The same preferably applies to the at least one Zener diode 45.1, 45.2. The at least one Zener diode 45.1, 45.2 can have a breakdown voltage in a range from 0.1 V to 10 V, in particular from 0.5 V to 8 V, in particular from 1 V to 7 V, in particular from 2 V to 6 V.

[0100] The plug connection part 4 formed with the ignition suppression means 39 ensures in particular that an ignition effect in the area of ​​the connecting cable 24 is avoided.

[0101] Ignition suppression is further promoted by the connecting cable 24 having a shield, in particular electrical and / or magnetic, and / or by the circuit 28 being enclosed by an encapsulation, in particular a potting compound, in particular a potting compound made of a non-electrically conductive material, in particular a plastic material. A further embodiment of a plug-in connection part 4a, in particular an ignition suppression means 39a, is described with reference to Fig. 5. The plug-in connection part 4a differs from the previously described embodiment in the design of the ignition suppression means 39a. Otherwise, the construction of the plug-in connection part 4a corresponds to that of the previously described plug-in connection part 4a.

[0102] The ignition suppression means 39a is electrically contacted between the operating voltage contact 29.1, in particular the current conditioning device 30 and / or the smoothing capacitor 38, and the amplifier device 33, in particular the feed inductance 37.

[0103] The ignition suppression means 39a has an electrical resistor 46, which is arranged, in particular, in a series circuit between the power conditioning device 30 and the amplifier device 33. The ignition suppression means 39a has two diodes 47.1, 47.2, in particular rectifier diodes, in particular Schottky diodes. As an alternative to the Schottky diodes, Zener diodes could be used. These are arranged between the power conditioning device 30 and the amplifier device 33, on the one hand, and the reference potential contact 29.2, on the other hand, in particular in a parallel circuit with the amplifier device 33, in particular with the power supply connection of the amplifier device 33, and / or with the feed inductance 37 and / or with the primary coil 23.

[0104] The ignition suppression means 39a configured in this way prevents the electrical energy stored in the amplifier device 33 from reacting with the circuit terminal 29. In particular, the maximum voltage and / or energy that can be applied between the power supply contacts 29.1, 29.2, in particular the maximum voltage and / or energy that can be applied by the amplifier device 33, is limited. Thus, it is possible to prevent a voltage and / or energy that would lead to an ignition spark from being reached.

[0105] The design of the ignition suppression means 39a with the resistor 46 limits the maximum electrical power that can be transmitted, particularly from the amplifier device 33, to the circuit terminal 29. The resistor 46 is optional.

[0106] The redundant design of diodes 47.1 and 47.2 is also optional. Multiple redundancy of diodes 47.1 and 47.2, particularly double redundancy, or even triple redundancy, is advantageous.

[0107] The measuring system 1, in particular the connection device 2, in particular the plug connection part 4a, advantageously ensure that an ignition effect is reliably prevented in the event of a fault, in particular in the event of a break in the connecting cable 24 or in the event of improper use.

[0108] The amplifier device 33 ensures signal transmission between the plug connection part 4a and the mating plug connection part 5 in a particularly reliable and robust manner. The resulting increased electrical energy that can be stored by the plug connection part 4a is potentially sufficient to provide an ignition effect, particularly in the connecting cable 24. The ignition suppression means 39a advantageously ensures that a reaction of the electrical energy stored in the plug connection part 4a to the circuit connection 29 is reliably prevented. The ignition suppression means 39a reliably prevents the energy required for spark ignition and / or thermal ignition from being delivered to the circuit connection 29, particularly to the connecting cable 24. The plug connection part 4a can be operated safely and reliably in potentially explosive environments.

[0109] Preferably, the signal processing device 25 is also designed to be intrinsically safe in the sense of explosion protection. Such a measuring system 1, in particular comprising the above-described connection device 2 and the intrinsically safe signal processing device 25, is particularly robust in operation and can be operated safely in an explosive environment.

Claims

Patent claims 1. Plug connection part (4, 4a) for inductively transmitting energy and / or signals in an explosive environment, in particular for a measuring system (1), comprising 1.1 an electrical circuit (28) with a circuit connection (29) for supplying the plug connection part (4) with electrical energy, and 1.2 a primary coil (23) in the circuit (28) for inductive coupling with a secondary coil (11), characterized by 1.3 an ignition suppression means (39, 39a) in the circuit (28) for preventing an ignition effect in the event of a fault by limiting a reaction of the electrical energy to the circuit terminal (29).

2. Plug connection part (4, 4a) according to claim 1, characterized in that the circuit (28) has an amplifier device (33) for amplifying the energy and / or signals which are supplied to the primary coil (23).

3. Plug connection part (4, 4a) according to claim 2, characterized in that the amplifier device (33) has a total electrical inductance of at least 0.1 mH.

4. Plug connection part (4, 4a) according to claim 2 or 3, characterized in that the ignition suppression means (39, 39a) is contacted in the circuit (28) between the amplifier device (33) and the circuit terminal (29).

5. Plug connection part (4, 4a) according to one of the preceding claims, characterized by a current conditioning device (30) which is contacted in the circuit (28) between the circuit connection (29) and the ignition suppression means (39, 39a).

6. Plug connection part (4, 4a) according to one of the preceding claims, characterized in that the ignition suppression means (39, 39a) is connected directly to the circuit connection (29).

7. Plug connection part (4, 4a) according to one of the preceding claims, characterized by a connecting cable (24) on the circuit connection (29), wherein the ignition suppression means (39, 39a) is designed to prevent an ignition effect in the connecting cable (24).

8. Plug connection part (4, 4a) according to one of the preceding claims, characterized in that the ignition suppression means (39, 39a) is designed to limit an electrical energy and / or power potentially contributing to the ignition of an explosive composition in the explosive environment.

9. Plug connection part (4, 4a) according to one of the preceding claims, characterized in that the ignition suppression means (39, 39a) is designed to dissipate electrical energy stored in the circuit (28).

10. Plug connection part (4, 4a) according to one of the preceding claims, characterized in that the ignition suppression means (39, 39a) has at least one diode (41.1 to 45.1, 41.2 to 45.2, 47.1, 47.2) for limiting a maximum connection voltage at the circuit connection (29).

11. Plug connection part (4, 4a) according to claim 10, characterized in that the ignition suppression means (39, 39a) has at least two of the diodes (41.1 to 45.1, 41.2 to 45.2) between two power supply contacts (29.1, 29.2) of the circuit connection (29).

12. Plug connection part (4) according to claim 10 or 11, characterized in that the ignition suppression means (39) has at least two rectifier diodes (41.1, 41.2) between an operating voltage contact (29.1) of the circuit connection (29) and a first signal line contact (29.3) of the circuit connection (29), between the first signal line contact (29.3) and a reference potential contact (29.2) of the circuit connection (29), between the operating voltage contact (29.1) and a second signal line contact (29.4) of the circuit connection (29), and between the second signal line contact (29.4) and the reference potential contact (29.2).

13. Plug connection part (4) according to one of claims 10 to 12, characterized in that the ignition suppression means (39) has at least two Z-diodes (45.1, 45.2) between two power supply contacts (29.1, 29.2) of the circuit connection (29).

14. Plug connection part (4a) according to one of claims 10 to 13, characterized in that the ignition suppression means (39a) which has at least one diode (41.1 to 45.1, 41.2 to 45.2, 47.1, 47.2) and / or at least one resistor (46), wherein in the circuit (28) the current conditioning device (30) is contacted between these and an operating voltage contact (29.1) of the circuit connection (29).

15. Plug connection part (4, 4a) according to one of the preceding claims, characterized in that its energy storage capacity exceeds an ignitability limit when used as intended.

16. Connection device (2) for inductive transmission of energy and / or signals, comprising 16.1 a plug connection part (4, 4a) according to one of the preceding claims, and 16.2 a counter-connector part (5) for reversibly detachable connection to the connector part (4, 4a).

17. Measuring system (1), with 17.1 at least one sensor (3), and 17.2 a connection device (2) according to claim 16.

18. Measuring system (1) according to claim 17, characterized by a signal processing device (25) for processing signals transmitted via the connection device (2).

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