Switching device for operation with different input control voltages

Abstract

The invention relates to a switch device (10) in particular for operation with different input control voltages. A current measurement path (50), which has a predefined electrical resistor (51) and a current sensor (52) connected in series thereto, is connected to the input terminals (30, 31) of the switching device (10). The current value measured by the current sensor (52) is supplied to a control and evaluation device (70) which determines a voltage value based on the predefined electrical resistance and the measured current value and checks whether the determined voltage value can be assigned to a predefined input control voltage value from several stored predefined input control voltage values. If it can, the switch-on and switch-off threshold voltage values belonging to this input control voltage value are provided to the control and evaluation device (70) for further operation of the switching device (10).

Description

[0001] Switching device for operation with different input control voltages

[0002] Description

[0003] The present invention relates to a switching device which is particularly suitable for operation with different input control voltages.

[0004] Switching devices are characterized, among other things, by the fact that, at a given input control voltage, they ensure that a relay or contactor is switched on above a given switch-on voltage threshold and switched off when the voltage falls below a given switch-off voltage threshold. Switching devices that can be operated with different input control voltages are known. Common input control voltages are 24 V, 48 V, 60 V, 120 V, and 230 V. The input control voltages can be either AC or DC.

[0005] Such a switching device is known, for example, from EP 3 375 004 B1. The known switching device is designed for several different rated voltage ranges, ranging from approximately 24 volts to 240 volts. The known switching device has a control unit that measures the output voltage of a rectifier supplied to its input side and evaluates the measured voltage by determining which of the specified voltage ranges the measured control voltage lies in. Subsequently, a lower switch-on voltage threshold and an upper switch-off voltage threshold are adjusted depending on the determined specified voltage range.

[0006] The present invention is based on the object of creating an alternative switching device that can be operated with several different input control voltages, in which susceptibility to interference from external influences can be minimized. A core idea of ​​the invention can be seen in creating a switching device that configures itself, in particular depending on an applied input control voltage. For this purpose, an input control voltage applied to the switching device is not fed directly to a control and evaluation device.Instead, the current is measured in a current path connected to the input terminals of the switching device, which comprises a series circuit comprising an electrical resistor with a predetermined resistance value and a current sensor. The measured current value is fed to the control and evaluation device, which then determines a voltage value depending on the predetermined resistance value of the electrical resistor and the measured current value and checks whether the determined voltage value can be assigned to a predetermined input control voltage value from several predetermined input control voltage values ​​stored in the switching device. If so, the switch-on and switch-off threshold voltage values ​​associated with this input control voltage value are made available to the control and evaluation device for the further operation of the switching device.

[0007] The above-mentioned technical problem is solved by the features of claim 1.

[0008] Accordingly, a switching device, in particular a self-learning switching device, is provided, which is particularly designed for operation with different input control voltages. The switching device preferably has the following features: a first and a second input terminal for applying an input control voltage, a current measuring path connected to the first and second input terminals, which has a predetermined electrical resistance, i.e., an electrical resistance with a predetermined resistance value, and a current sensor connected in series therewith, which is designed to measure a current flowing through the current path, a switching device—for example, an electromechanical switch or an optocoupler—which is designed to close and open at least one load circuit and is electrically connected to a control circuit, a controllable switching element designed to close and open the control circuit,a control and evaluation device having a first input electrically connected to the current sensor, a memory device electrically connected to the control and evaluation device, in which an assignment table is stored which assigns a switch-on voltage threshold value and a switch-off voltage threshold value to each predetermined input control voltage value from a plurality of n different predetermined input control voltage values, wherein the control and evaluation device is designed to i) determine a voltage value as a function of a current value measured by the current sensor and the predetermined electrical resistance and to check whether the determined voltage value can be assigned to one of the n different predetermined input control voltage values, and if so, ii) as a function of the,to read the associated switch-on voltage threshold value and the associated switch-off voltage threshold value from the memory device for the predetermined input control voltage value assigned to the determined voltage value and to use them as the current switch-on or,

[0009] To provide a switch-off threshold.

[0010] Advantageous further developments and refinements are the subject of the subclaims.

[0011] For example, the switching device has a voltage supply device with a first and a second output, wherein the voltage supply device is designed to generate a first predetermined voltage when an input control voltage is applied to the first and second input terminals.

[0012] To generate a predetermined DC supply voltage and a second predetermined DC supply voltage, and to provide the first predetermined DC supply voltage at the first output and the second predetermined DC supply voltage at the second output, wherein the control and evaluation device has a voltage supply terminal that is electrically connected to the second output of the voltage supply device. The switching device is connected to the first output via the control circuit.

[0013] To activate and deactivate the switching device, the control and evaluation device is preferably designed to generate an activation signal if, after execution of step ii), a voltage value determined by the control and evaluation device as a function of a current value measured by the current sensor is greater than or equal to the currently stored switch-on voltage threshold value, wherein the controllable switching element is designed to close the control circuit in response to the activation signal, and wherein the control and evaluation device is designed to generate a deactivation signal if, after execution of step ii), a voltage value determined by the control and evaluation device as a function of a current value measured by the current sensor is less than or equal to the currently stored switch-off voltage threshold value, wherein the controllable switching element is designed toto open the control circuit in response to the deactivation signal.

[0014] According to an advantageous embodiment, the controllable switching element can be an integral component of the control and evaluation device. In this case, the controllable switching element preferably forms an open collector output of the control and evaluation device.

[0015] According to an alternative advantageous embodiment, the controllable switching element can be designed as a separate component, wherein the control and evaluation device has a control output for applying the activation signal or the deactivation signal, and wherein the control output is electrically connected to a terminal of the controllable switching element. The switching device is preferably a self-learning switching device.This is advantageously achieved in that the control and evaluation device is designed, after execution of steps i) and ii), to continuously determine a voltage value as a function of a current value measured by the current sensor and to check whether this determined voltage value can be assigned to another of the n different predetermined input control voltage values. If this is the case, to read out the associated switch-on voltage threshold value and the associated switch-off voltage threshold value from the memory device as a function of the predetermined input control voltage value assigned to the determined voltage field and to provide or store these values ​​as new current switch-on and switch-off voltage threshold values. In this way, the switch-on and switch-off voltage threshold values ​​are automatically adjusted during operation of the switching device.

[0016] According to an advantageous development, the switching device can have a third input terminal that is electrically connected to a second input of the control and evaluation device. The control and evaluation device is then preferably designed to delete the currently stored or provided switch-on and switch-off voltage threshold values ​​in response to a first control signal that can be applied to the third input terminal and subsequently to repeat steps i) and ii). Thanks to this measure, the switch-on and switch-off voltage threshold values ​​can be reset and the switching device can be restarted in order to readjust the switch-on and switch-off voltage threshold values ​​with respect to a different input control voltage.

[0017] To enable an operator to determine the currently valid switch-on and switch-off voltage thresholds at any time, the switching device can have an optical and / or acoustic output device. In this case, the control and evaluation device can be configured to cause the switching device to output optical and / or acoustic information via the optical and / or acoustic output device, which represents the currently stored switch-on and switch-off thresholds and / or the associated predetermined input control voltage value.

[0018] According to an advantageous development, the control and evaluation device can be designed to cause the switching device, in response to a second control signal that can be applied to the third input terminal, to output optical and / or acoustic information via the optical and / or acoustic output device, which represents the currently provided or stored switch-on and switch-off voltage threshold values ​​and / or the associated predetermined input control voltage value.

[0019] The controllable switching element is preferably a semiconductor switch, whereby the switching device can be designed as an electromechanical switch, e.g., a relay or contactor, or as an optocoupler. The electromechanical switch is preferably designed as an on / off switch or a changeover switch.

[0020] The switching device expediently has at least two output terminals connected to the electromechanical switch for connecting at least one load circuit.

[0021] The electromechanical switch can, for example, have an excitation coil connected in series with the controllable switching element.

[0022] The control and evaluation device can expediently be designed as a microcontroller.

[0023] Advantageously, the storage device can be an integral part of the control and evaluation device.

[0024] If the storage device is a separate component, it can be, for example, a non-volatile electronic memory module, such as an EEPROM. The invention is explained in detail below in conjunction with the accompanying drawings. In the drawings:

[0025] Figure 1 shows the block diagram of an exemplary switching device in which the invention is implemented, and

[0026] Figure 2 shows the block diagram of another exemplary switching device in which the invention is implemented.

[0027] Figure 1 shows the block diagram of an exemplary switching device 10, which is particularly designed for operation with different input control voltages. The switching device 10 is preferably designed as a self-learning switching device, as will be explained in more detail below.

[0028] The switching device 10 has a first input terminal 30 and a second input terminal 31, to which an input control voltage, for example in the form of a direct voltage or an alternating voltage, can be applied. It should be noted that the input terminal 31 can preferably function as a ground terminal. By way of example only, a direct voltage source 20 can be connected to the two input terminals 30 and 31 via a switch 21. In the event that an alternating voltage is also to be applied as the input control voltage, a bridge rectifier 40 can be implemented in the switching device 10 and can be connected to the two input terminals 30 and 31. To smooth the output voltage of the bridge rectifier 40, a smoothing capacitor 41 can be connected in parallel to the output of the bridge rectifier 40.

[0029] Furthermore, a current measuring path 50 is electrically connected to the two input terminals 30 and 31. The current measuring path 50, if present, is arranged downstream of the bridge rectifier 40 and has an electrical resistor with a predetermined resistance value and a current sensor 52 connected in series therewith, which is designed to measure a current flowing through the current path 50. An input control voltage that can be applied to the input terminals 30 and 31 is supplied to a voltage supply device 60. For this purpose, the voltage supply device 60 is electrically connected to the input terminals 30 and 31. The voltage supply device 60 can have a DC converter 61, also called a DC converter, which converts an input control voltage applied to the input terminals 30 and 31 into a DC voltage of, for example, 12 V. A smoothing capacitor 62 can be provided at the output of the DC converter 61.The DC output voltage generated by the DC-DC converter 61 is supplied to a first output 64 of the voltage supply device 60. Furthermore, the DC output voltage of the DC-DC converter 61 is supplied to a voltage regulator 63, which, for example, generates a supply voltage for a control and evaluation device 70 from the 12 V DC voltage. For this purpose, the voltage regulator 63 converts the 12 V DC input voltage, for example, into a 3.3 V output voltage, which is supplied via an output 65 of the voltage supply device 60 to a voltage supply terminal 71 of the control and evaluation device 70. Thanks to the voltage supply device 60, the switching device 10 can be operated using only a two-wire cable, since both the microcontroller 70 and the electromechanical switch 100 are supplied via the input control voltage applied to the input terminals 30 and 31.

[0030] The control and evaluation device 70 can expediently be embodied as a microcontroller. The microcontroller 70 can further have an analog input 72 connected to an output of the current sensor 72. The analog input 72 is connected to an analog / digital converter 79, referred to as an A / D converter for short, of the microcontroller 70. The A / D converter 79 converts the analog current values ​​measured by the current sensor 52 into digital current values. In a manner known per se, the microcontroller 70 can have a microprocessor 76 and a memory 95 in which, for example, firmware for controlling and monitoring the switching device 10 is stored. The output of the A / D converter 79 is connected to the input side of the microcontroller 70.

[0031] According to an exemplary embodiment, the switching device 10 has a switching device 100 designed as an electromechanical switch. The electromechanical switch 100 can be designed, for example, as a relay or contactor. The electromechanical switch 100 has an excitation coil 101 arranged in a control circuit 103, which is electrically connected in series with a controllable switching element 110. The switching element 110 is designed, for example, as a separate component that can be connected upstream or downstream of the excitation coil 101. The control circuit 103 is electrically connected to the output 64 of the voltage supply device 60. The switching element 110 can, as shown in Figure 1, be connected between the terminal 64 and the excitation coil 101. In a manner known in the art, at least one switching element 102 of the switching device 100 is coupled to the excitation coil 101.The switching element 102 can be designed, for example, as an on / off switch or a changeover switch, as shown by way of example in Figure 1. According to the exemplary implementation, the switching device 10 according to Figure 1 has three output terminals 120-122, to which two load circuits can be connected, which can be switched on or off by means of the switching element 102.

[0032] Instead of the electromechanical switch 100, a switching device 100' designed as an optocoupler can be implemented in the switching device 10. This is illustrated in Figure 2 using another exemplary switching device 10' in which the optocoupler 100' is implemented. The components of the switching device 10' that correspond to the components of the switching device 10 according to the exemplary embodiments have been provided with the same reference numerals. The optocoupler 100' can contain, in a manner known per se, a light-emitting diode as the optical transmitter 101' and a photodiode as the optical receiver 102'. In this case, the optical transmitter 101' is connected to the control circuit 103. The optical receiver 102' is connected to the output terminals 120 and 122 of the switching device 10', to which a load circuit (not shown) can be connected.The output of the optocoupler 100' can be designed, for example, as a transistor, as shown in Figure 2, as a triac or thyristor.

[0033] Furthermore, for example, an optical and / or acoustic output device 80 can be implemented in the switching device 10, which is preferably electrically connected to a digital output 74 of the microcontroller 70. The optical and / or acoustic output device 80 has the task of signaling to an operator the input control voltage currently applied to the switching device 10 as well as the associated switch-on and switch-off voltage threshold values, which can be stored in the memory 95.

[0034] Furthermore, the switching device 10 can expediently have a separate memory device 90, which can be embodied as an EEPROM. For example, a lookup table can be stored in the memory device 90, which assigns a switch-on voltage threshold and a switch-off voltage threshold to different predefined input control voltages. For example, voltage values ​​of 24 V, 48 V, 60 V, 120 V, and 230 V can be stored as predefined input control voltages. As already mentioned at the beginning, depending on the implementation of the switching device 10, AC voltages and / or DC voltages can be processed by the switching device 10 as input control voltages. For the sake of simplicity of explanation, it is assumed that the DC voltage values ​​of 24 V, 48 V, and 60 V, as well as the associated predeterminable switch-off and switch-on voltage thresholds, are stored in the memory device 90.Alternatively or additionally, these values ​​can also be stored in the memory 95 integrated in the microcontroller 70. In this case, the separate memory device 90 could be omitted.

[0035] According to the exemplary embodiment shown in Figure 1, the control and evaluation device 70 designed as a microcontroller has a further, preferably digital, output connection 75, via which a control signal can be supplied to the controllable switching element 110 in the form of an activation signal or a deactivation signal for switching the switching element 110 on or off.

[0036] Furthermore, according to the exemplary embodiment, the microcontroller 70 preferably has a connection 77 via which the microcontroller 70 or the microprocessor 76 can communicate with the memory device 90. The control and evaluation device 70 and the memory device can preferably be connected to one another via an SPI (Serial Peripheral Interface)-based bus. In this case, the connection 77 is designed as an SPI-based interface, with the memory device 90 then also having an SPI-based interface. The microcontroller 70 is designed to transmit, for example, a request command, which, among other things, contains a determined voltage value that corresponds to an applied input control voltage, to the memory device 90 via the connection 77 in order to request the memory device 90 to transmit the switch-on and switch-off voltage threshold value associated with this voltage value to the microcontroller 70.The control and evaluation device 70 can be designed to store the switch-on and switch-off voltage threshold values ​​read from the memory device 90 as currently provided switch-on and switch-off voltage threshold values ​​in the memory 95 of the microcontroller 70.

[0037] It should be noted at this point that instead of the controllable switching element 110, a controllable switching element 110' can also be used in the switching device 10. This is illustrated in Figure 2 using the exemplary switching device 10'. The switching element 110' is preferably integrated as an open collector output in a microcontroller 70', as shown in Figure 2. In this case, the emitter is connected to an internal ground of the microcontroller 70'. In this case, the microcontroller 70' has a terminal 75' to which the control circuit 103 or the optical transmitter 101' can be connected. If, however, the electromechanical switch 100 shown in Figure 1 is used as the switching device, the ground terminal of the excitation coil 101 is connected to the terminal 75', whereas when the optocoupler 100' is used, the cathode terminal of the optical transmitter 101' is connected to the terminal 75'.Furthermore, the microcontroller 70' can be designed similarly or essentially identically to the microcontroller 70 of the switching device 10. For example, the microcontroller 70' can have a voltage supply connection 71', a connection 74', an analog input 72', a microprocessor 76', a memory 95', and a further input 73'. The mode of operation of the switching device 10 and the switching device 10' can preferably be essentially the same, so that the microcontroller 70 according to Figure 1 could easily be replaced by the microcontroller 70'. The switching device 10 can have a third input connection 32, which can be connected to a further, preferably digital input 73 of the control and evaluation device 70. For example, an operator can apply a first control signal to the input 32 of the switching device 10 in order to be informed of the current configuration, i.e., the input control voltage currently used by the switching device 10.Microcontroller 70 is configured to evaluate the first control signal arriving at input 73 and to transmit a corresponding control signal via output 74 to optical and / or acoustic output device 80, which then outputs the currently configured input control voltage to an operator in optical or acoustic form. Predetermined codes, such as numbers, can be used for this purpose. Each of these codes is assigned one of the predetermined input control voltages and the associated switch-on and switch-off voltage threshold values. For example, number 1 can be assigned to an input control voltage of 24V, number 2 to an input control voltage of 24V, and number 3 to an input control voltage of 48V.Preferably, the optical and / or acoustic output device 80 is then designed to output a corresponding number of flashing pulses and / or a corresponding voice utterance depending on the respective digit.

[0038] For example, a reset signal can be applied to input terminal 32 as a second control signal, which is fed via input 73 to control and evaluation device 70. The control and evaluation device 70 can be configured to delete or reset the switch-on and switch-off voltage threshold values ​​currently stored in memory 95 in response to the reset signal.

[0039] The function and operation of the switching device 10 shown as an example in Figure 1 is explained in more detail below.

[0040] Let us now assume that three possible DC voltages are stored in memory 90 as input control voltage values, for example, 24 V, 48 V, and 60 V, as well as the corresponding turn-on voltage thresholds and turn-off voltage thresholds, for example, in the form of a lookup table. These three voltage values ​​are also conveniently stored as reference values ​​in memory 95 of microcontroller 70. Furthermore, let us assume that switching device 10 is to be put into operation for the first time.

[0041] For this purpose, for example, the external DC voltage source 20, which supplies a DC voltage of 24 V, for example, is connected to the input terminals 30 and 31, and the switch 21 is closed. After the switch 21 is closed, the current in the current measuring path 50 caused by the input control voltage is measured by the current sensor 52. The electrical resistor 51, which is connected in series with the current sensor 57 and is preferably low-ohmic and whose value is known, preferably serves to set a base load current through the current path 50 in order to minimize susceptibility to interference from external influences. The resistance value of the resistor 51 is stored, for example, in the memory 95 and is thus known, together with the three reference values ​​of 24 V, 48 V, and 60 V, to the microcontroller 70 or the microprocessor 76. The analog value measured by the current sensor 52 is fed to the A / D converter 79 of the microcontroller 70 via the analog input 72.The microprocessor 76 of the microcontroller 70 is programmed to determine a voltage value based on the digital current measurement received via the A / D converter 79 and the known resistance value of the electrical resistor 51. The microcontroller 70 or the microprocessor 76 can preferably be configured to check whether the determined voltage value can be assigned to one of the reference values ​​stored in the memory 95. In the present case, the microprocessor 76 recognizes that the determined voltage value can be assigned to the reference value 24V.

[0042] The microcontroller 70, or the microprocessor 76 implemented therein, is programmed to transmit the detected reference value of 24V via output 77 to the memory device 90 and to cause the memory 90 to transmit the switch-on and switch-off voltage threshold values ​​associated with the transmitted reference value back to the microcontroller 70 and make them available to the microcontroller 70 for further use. The switch-on and switch-off voltage threshold values ​​arriving at terminal 77 are stored, for example, in the memory 95 of the microcontroller 70 as the switch-on and switch-off voltage threshold values ​​currently to be used. In other words: After initial commissioning, the switching device 10 has automatically configured itself with respect to the input control voltage applied to the input terminals 30 and 31.

[0043] It should be noted that during operation, the current sensor 52 expediently continuously measures the current through the current measuring path 50 and transmits the current measured values ​​to the microcontroller 70 at regular intervals, preferably almost continuously.

[0044] If, after initial commissioning, the microcontroller 70 determines that the 24V DC voltage applied to the input terminals 30 and 31 is present continuously for a defined period of time - i.e., the microprocessor 76 determines a voltage value during this period that is greater than or equal to the switch-on voltage threshold stored in the memory 95 - the microcontroller 70 or the microprocessor 76 applies an activation signal to the digital output 75, which ensures that the switching element 110 is closed. Consequently, the output voltage of, for example, 12V applied to the output 64 of the DC-DC converter 61 is supplied to the electromechanical switch 100 or the excitation coil 101, so that the switching element 102 of the electromechanical switch 100 is switched accordingly.In the embodiment shown, a current-carrying excitation coil 101 ensures that the switch 102 closes a load current circuit at the terminals 120 and 121.

[0045] Advantageously, the microcontroller 70 is configured to transmit a corresponding control signal, for example, a binary-coded 1, to the optical and / or acoustic output device 80 via output 74 after initial commissioning. The optical and / or acoustic output device 80 is configured to evaluate the binary-coded 1 and output the number 1, for example, through a single flashing pulse and / or a corresponding voice utterance by an operator. The number 1 output in this way signals to an operator that the switching device 10 is currently operating with an input control voltage of 24V.

[0046] The electromechanical switch 100 remains in switching state 1, i.e., current flows through the excitation coil 101, until the input control voltage at the input terminals 30 and 31 falls below the switch-off voltage threshold stored in memory 95. The microcontroller 70 detects this because the current continuously measured by the current sensor 52 through the current path 50 drops, so that the microprocessor 76 determines a voltage value that lies below the switch-off voltage threshold stored in memory 95. In response to this, the microprocessor 76 applies a deactivation signal to the digital output 75. In response to the deactivation signal, the switching element 110 is opened.At this moment, the excitation coil 101 no longer carries current and the electromechanical switch 100 goes into a second switching state in which a second load current circuit (not shown), which is connected to the terminals 121 and 122, is now closed via the switch 102, while the first load current circuit (not shown) is opened.

[0047] As already mentioned above, according to an advantageous embodiment, an operator can apply a first control signal to input 32 of switching device 10 in order to be informed of the current configuration, i.e. the input control voltage currently used by switching device 10. Microcontroller 70 is designed to evaluate a corresponding control signal arriving at input 73 and to transmit a corresponding control signal, in the present embodiment a binary-coded 1, to optical and / or acoustic output device 80 via output 74. Optical and / or acoustic output device 80 is designed to evaluate the binary-coded 1 and output the number 1, for example by means of a single flashing pulse and / or a corresponding spoken utterance by an operator.The number 1 output in this way signals to an operator that the switching device 10 is currently operated with an input control voltage of 24V.

[0048] Via input 32, an operator can apply a second control signal, a so-called reset signal, to input 73 of microcontroller 70. As already explained above, microcontroller 70 or microprocessor 76 is configured to delete the switch-on and switch-off voltage threshold values ​​currently stored in memory 95 in response to a reset signal.

[0049] If, after a reset of the switching device 10, an input control voltage, for example an input control voltage of 48 V, is again applied to the input terminals 30 and 31 of the switching device 10, the configuration procedure previously described with regard to the initial commissioning is carried out again, so that at the end of a proper configuration phase, the switch-on and switch-off voltage threshold values ​​associated with the reference value of 48 V are read from the memory 90 by the microcontroller 70 and stored in the memory 95 as the current switch-on and switch-off voltage threshold values.

[0050] The exemplary switching device 10 can also be operated in a so-called self-learning mode in which the switching device 10 automatically reconfigures itself, ie, adjusts itself to a new input control voltage value and to the associated turn-on and turn-off voltage thresholds.

[0051] Let us now assume that the switching device 10, in accordance with the initial commissioning described above, is configured for an input control voltage value of 24 V and the associated switch-on and switch-off voltage threshold values ​​stored in memory 95. As already mentioned, the sensor 52 is designed to continuously measure the current through the current path 50 while an input control voltage is applied to the input terminals 30 and 31, wherein the measured current value is fed to the microprocessor 76 of the microcontroller 70 via the A / D converter 79. The microcontroller 70 or the microprocessor 76 is designed to determine a voltage value at regular intervals, or almost continuously, from the measured current values ​​arriving at the input 72 and to check whether the determined voltage value can be assigned to one of the three stored reference values, namely 24 V, 48 V, and 60 V.

[0052] Now assume that during operation, the input control voltage applied to input terminals 30 and 31 is increased from 24 V, for example, to 48 V. This means that switching element 110 is still closed and excitation coil 101 is energized.

[0053] Let us now assume that the changed input control voltage, in this case the new input control voltage 48V, is applied for at least a predetermined period of time and that the current sensor 52 measures a correspondingly increased current value for the predetermined period of time, which is fed to the microprocessor 76 via the input 72 and the A / D converter 79. In this case, the microprocessor 76 determines voltage values ​​during the predefined period of time and establishes that the determined voltage values ​​can all be assigned to the reference value of 48V stored in the memory 95 during the predetermined period of time. In response to this, the microprocessor 76 requests the memory device 90 via the connection 77 to send the switch-on and switch-off voltage threshold values ​​associated with the reference value of 48V. The microcontroller 70 orFor example, the microprocessor 76 is programmed to delete the turn-on and turn-off voltage thresholds associated with the old input control voltage of 24 V and replace them with the new turn-on and turn-off voltage thresholds, or to overwrite the old turn-on and turn-off voltage thresholds in the memory 95 with the new received turn-on and turn-off voltage thresholds associated with the input control voltage of 48 V.

[0054] The exemplary switching device 10 is thus capable of self-learning, i.e., automatically detecting whether a new input control voltage has been applied to input terminals 30 and 31 during ongoing operation. In response to this, the switching device 10 configures itself, i.e., the microcontroller 70 ensures that the switch-on and switch-off voltage thresholds associated with the new input control voltage of 48 V are now activated by writing them to memory 95. This means that if the current input control voltage of 48 V applied to input terminals 30 and 31 falls below its associated switch-off voltage threshold, the microcontroller 70 detects this and subsequently opens the switching element 110.

[0055] As already mentioned, the functioning of the switching device 10 essentially does not change if the microcontroller 70' is implemented in the switching device 10 instead of the microcontroller 70 and / or the optocoupler 100' is implemented in the switching device 10 instead of the electromechanical relay 100.

Claims

Patent claims 1. Switching device (10, 10'), in particular for operation with different input control voltages, comprising: a first and a second input terminal (30, 31) for applying an input control voltage (20), a current measuring path (50) connected to the first and second input terminal (30, 31), which has a predetermined electrical resistance (51) and a current sensor (52) connected in series therewith, which is designed to measure a current flowing through the current path (50), a switching device (100, 100') designed to close and open at least one load current circuit and is electrically connected to a control current circuit (103), a controllable switching element (110, 110') designed to close and open the control current circuit (103), a control and evaluation device (70, 70') having a first input (72) electrically connected to the current sensor (52), a the control and evaluation device (70,70') electrically connected memory device (90, 95), in which an assignment table is stored which assigns a switch-on voltage threshold value and a switch-off voltage threshold value to each predetermined input control voltage value from a plurality of n different predetermined input control voltage values, wherein the control and evaluation device (70, 70') is designed to i) determine a voltage value as a function of a current value measured by the current sensor (52) and the predetermined electrical resistance (51) and to check whether the determined voltage value can be assigned to one of the n different predetermined input control voltage values, and if so, ii) determine the associated switch-on voltage threshold value and the associated switch-off voltage threshold value as a function of the predetermined input control voltage value assigned to the determined voltage value. Read the voltage threshold value from the memory device (90, 95) and provide it as the current switch-on or switch-off threshold value. Switching device according to claim 1, further comprising a voltage supply device (60) with a first and a second output (64, 65), wherein the voltage supply device (60) is configured to generate a first predetermined DC supply voltage and a second predetermined DC supply voltage when an input control voltage is applied to the first and second input terminals (30, 31), and to provide the first predetermined DC supply voltage at the first output (64) and the second predetermined DC supply voltage at the second output (65), wherein the control and evaluation device (70, 70') has a voltage supply terminal (71, 71') that is electrically connected to the second output (65) of the voltage supply device (60).wherein the switching device (100) is electrically connected to the first output (64) via the control circuit (103). Switching device according to claim 1 or 2, wherein the control and evaluation device (70, 70') is designed to generate an activation signal if, after execution of step ii), a voltage value determined by the control and evaluation device (70) as a function of a current value measured by the current sensor (52) is greater than or equal to the switch-on voltage threshold value stored as currently, wherein the controllable switching element (110) is designed to close the control circuit (103) in response to the activation signal, and wherein the control and evaluation device (70, 70') is designed to generate a deactivation signal if, after execution of step ii), a voltage value determined by the control and evaluation device (70,70') as a function of a current value measured by the current sensor (52) is less than or equal to the currently stored switch-off voltage threshold value, wherein, the controllable switching element (110, 110') is designed to open the control circuit (103) in response to the deactivation signal. Switching device according to one of the preceding claims, wherein the controllable switching element (110, 110') is an integral part of the control and evaluation device (70, 70'). Switching device according to claim 3, wherein the controllable switching element (110, 110') is designed as a separate component, and wherein the control and evaluation device (70, 70') has a control output (75, 75') for applying the activation signal or the deactivation signal, wherein the control output (75, 75') is electrically connected to a terminal of the controllable switching element (110, 110').Switching device according to one of the preceding claims, wherein the control and evaluation device (70, 70') is designed, after execution of steps i) and ii), to continuously determine a voltage value as a function of a current value measured by the current sensor (52) and to check whether this determined voltage value can be assigned to another of the n different predetermined input control voltage values, and if so, to read out the associated switch-on voltage threshold value and the associated switch-off voltage threshold value from the memory device (90, 95) as a function of the predetermined input control voltage value assigned to the determined voltage value and to provide them as new current switch-on and switch-off threshold values.Switching device according to one of the preceding claims, wherein the switching device (10) has a third input terminal (32) which is electrically connected to a second input (73, 73') of the control and evaluation device (70, 70'), wherein the control and evaluation device (70, 70') is designed to, in response to a signal applied to the third input terminal (32). applied first control signal to delete the switch-on and switch-off voltage threshold values ​​stored as current switch-on and switch-off threshold values ​​and then to repeat steps i) and ii).

8. Switching device according to one of the preceding claims, wherein the switching device (10) has an optical and / or acoustic output device (80), wherein the control and evaluation device (70) is designed to cause the switching device (10) to output optical and / or acoustic information via the optical and / or acoustic output device (80), which represents the switch-on and switch-off voltage threshold values ​​stored as current switch-on and switch-off threshold values ​​and / or the associated predetermined input control voltage value.

9. Switching device according to claim 7 and 8, wherein the control and evaluation device (70) is designed to cause the switching device (10) to output optical and / or acoustic information via the optical and / or acoustic output device (80) in response to a second control signal that can be applied to the third input terminal (32), which optical and / or acoustic information represents the switch-on and switch-off voltage threshold values ​​stored as current switch-on and switch-off threshold values ​​and / or the associated predetermined input control voltage value.

10. Switching device according to one of the preceding claims, wherein the controllable switching element (110, 110') is designed as a semiconductor switch and the switching device is designed as an electromechanical switch (100) or as an optocoupler (100').

11. Switching device according to claim 10, wherein the switching device (10) has at least two output terminals (120-122) connected to the electromechanical switch (100) for connecting at least one load circuit. Switching device according to claim 10 or 11, wherein the electromechanical switch (100) has an excitation coil (101) connected in series with the controllable switching element (110). Switching device according to one of the preceding claims, wherein the control and evaluation device (70, 70') is designed as a microcontroller. Switching device according to one of the preceding claims, wherein the memory device (95, 95') is an integral part of the control and Evaluation device (70, 70').

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