Method for monitoring a switching device and switching device

Abstract

A method for monitoring a switching device (1) comprises the steps of - changing the supply voltage (10) of the magnetic drive (2) from an operation value (11) to a monitoring value (12) for a monitoring time period (13), - monitoring an inductive signal (30) induced in the freewheeling circuit (3) during the monitoring time period (13). The switching device (1) is configured to switch by changing a supply voltage (10) for a solenoid (20) of a magnetic drive (2). The switching device (1) comprises a freewheeling circuit (3) arranged in series to the solenoid (20) of the magnetic drive (2).

Description

[0001] P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0002] 1

[0003] Description

[0004] METHOD FOR MONITORING A SWITCHING DEVICE AND SWITCHING DEVICE

[0005] The present disclosure relates to a method for monitoring a switching device . The present disclosure further relates to a switching device .

[0006] One obj ect to be achieved, inter alia, is to speci fy an improved method for monitoring a switching device which in particular allows to detect mal functions of the switching device . A further obj ect to be achieved is to speci fy an improved switching device which allows to carry out the method and which in particular allows to detect mal functions .

[0007] These obj ects are achieved, inter alia, by a method comprising the features of independent claim 1 and by a switching device comprising the features of claim 11 , respectively . Advantageous embodiments and further developments are the subj ect of the dependent patent claims .

[0008] According to at least one embodiment , the switching device is configured to switch by changing a supply voltage for a magnetic drive . The switching device is in particular switched during operation by interrupting the supply current .

[0009] For example , the switching device is arranged in a power line and is configured to interrupt the power line i f a failure or safety-relevant event is detected or i f it is intended to interrupt the power line by a user . The power line may be a power line of a motor drive train, for example for an electric car . P2024,0610 WO N / P24-1234WO01 August 4, 2025

[0010] 2

[0011] The switching device in particular comprises two states, wherein in a first state fixed and moveable contacts of the switching device are connected such that the power line is connected. In a second state the fixed and moveable contacts are separated and the power line is interrupted. For example, the fixed contacts are arranged on a contact bridge and the moveable contacts are connected to the power line.

[0012] The moveable contacts, i.e. the contact bridge, are moveable with respect to the fixed contact by the magnetic drive. The magnetic drive in particular comprises a fixed part and a moveable part. The fixed part comprises a core of a magnetic material such as ferrite or iron, around which a solenoid is wound. The moveable part preferably comprises a magnetic material such as ferrite or iron. The moveable part is in particular connected to the moveable contacts, i.e. the contact bridge, for example by a contact spring.

[0013] For example, if the solenoid is supplied with a supply voltage, the moveable part is attracted to the fixed part of the magnetic drive due to magnetic attraction. In this first state the contact bridge is pressed towards the fixed contacts due to the mechanical coupling to the magnetic drive, and the power line is closed.

[0014] If, for example, the supply voltage is interrupted, the moveable part of the magnetic drive is pushed away from the fixed part. For example, movement of the moveable part is caused by decompression of a spring of the magnetic drive that is compressed in the first state. In particular, the movement of the moveable part is transferred to the moveable contacts, resulting in opening of the contacts and interruption of the power line. P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0015] In particular, the switching device is an electromechanical switching device . For example , the switching device is a contactor .

[0016] According to at least one embodiment , the switching device comprises a freewheeling circuit . The freewheeling circuit in particular comprises at least one freewheeling diode and is arranged in series to the magnetic drive , in particular to the solenoid of the magnetic drive . The freewheeling circuit is in particular configured to eliminate flyback, which is a voltage spike emerging when the supply voltage of the solenoid is changed, reduced or interrupted . The freewheeling circuit / diode may also be referred to as a flyback circuit / diode , flywheel circuit / diode or snubber circuit / diode .

[0017] In at least one embodiment , the method for monitoring a switching device is configured to switch by changing a supply voltage for a solenoid of a magnetic drive , wherein the switching device further comprises a freewheeling circuit arranged in parallel to the solenoid of the magnetic drive , comprises a step of changing the supply voltage of the magnetic drive from an operation value to a monitoring value for a monitoring time period . The method further comprises a step of monitoring an inductive signal induced in the freewheeling circuit during the monitoring time period .

[0018] For example , the supply voltage for the solenoid is provided by a voltage source . The supply voltage may, for example , be changed by changing the output of the voltage source . However, preferably, the output of the voltage source is preferably constant , and the supply voltage is changed, for P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0019] 4 example from the operation value to the monitoring value or interrupted by a variable resistance or a switch . For example , the variable resistance can be implemented by using a transistor .

[0020] In particular, the operation value of the supply voltage is the supply voltage in the first state of the switching device , i . e . in a state where the contacts of the switching device are closed . The monitoring value of the supply voltage is preferably smaller than the operation value . Thus , a voltage spike emerges in the freewheeling circuit due to discharging the inductance , i . e . the solenoid of the magnetic drive . In particular, this inductive voltage is the inductive signal . The inductive signal is in particular detected by a monitoring unit of the freewheeling circuit . The inductive signal is further preferably compared to a predetermined threshold .

[0021] The monitoring time period in particular starts when the supply voltage is changed from the operation value to the monitoring value . At an end of the monitoring time period, the supply voltage is preferably changed back from the monitoring value to the operation value .

[0022] The change of the supply voltage is in particular controlled by a control unit configured to control the supply voltage . This means in particular, the control unit may control the voltage source or the variable resistance . The control unit may be a microcontroller, an application speci fic integrated circuit (AS IC ) , a field programmable gate array ( FPGA) or the like . P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0023] 5

[0024] The method described herein is in particular based on the following technical considerations . In the case of electronically driven electromagnetic switching devices , a defect in an electronic component may cause the device to no longer be able to be switched of f in short time . This is particularly problematic in a safety-related environment .

[0025] The method described herein makes use of the idea of monitoring a status of the electronics , in particular the freewheeling circuit , of the switching device regularly . This is in particular achieved by changing or interrupting the supply voltage of the solenoid for a monitoring time period, generating an inductive signal in the freewheeling circuit . This inductive signal can be detected and compared to a threshold by the monitoring unit . In particular, the inductive signal can only be properly detected i f the freewheeling circuit and / or the freewheeling diodes are intact .

[0026] I f the monitoring time period is particularly small , the method can be advantageously carried out during operation of the switching device . Hence , the method allows for a regular check whether the freewheeling circuit operates as intended . As a result , mal functions of the switching device can be detected .

[0027] According to at least one embodiment of the method, the monitoring value of the supply voltage is zero . Thus , the supply voltage may be interrupted during the monitoring time period . P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0028] 6

[0029] According to at least one embodiment of the method, the supply voltage is controlled by a control unit . This means in particular that the change of the supply voltage is controlled by a control unit configured to control the supply voltage . The control unit may be a microcontroller, an application speci fic integrated circuit (AS IC ) , a field programmable gate array ( FPGA) or the like .

[0030] According to at least one embodiment , the inductive signal is an inductive voltage . The inductive signal , i . e . the inductive voltage , is preferably monitored by a monitoring unit . The monitoring unit in particular comprises a voltage comparing device . The inductive voltage is in particular induced in the freewheeling circuit by discharging the inductance of the solenoid of the magnetic drive .

[0031] In particular, the inductive voltage is greater than the supply voltage . This means in particular that the inductive voltage has a bigger value than the supply voltage . Thus , i f the monitoring unit detects an inductive voltage in the freewheeling circuit after the supply voltage is changed from the operation value to the monitoring value , i . e . during the monitoring time period, the freewheeling circuit operates properly .

[0032] According to at least one embodiment , the method is carried out during operation of the switching device without tripping the switching device . In particular, the monitoring time period is particularly small such that the switching device is not tripped during the monitoring time period .

[0033] For example , a moveable part of the magnetic drive moves with respect to a fixed part of the magnetic drive after a P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0034] 7 starting time period . The starting time period in particular starts at the same point in time as the monitoring time period . This means in particular that the starting time period starts when the supply voltage is changed to the monitoring value . The starting time period in particular represents a lag time it takes for the moveable part to start moving due to mechanical inertia of the moveable part .

[0035] Preferably, the monitoring time period is shorter than the starting time period . Hence , the monitoring time period ends before the moveable part is set in motion . In other words , the magnetic drive is already supplied with the supply voltage having the operation value before the moveable part is set in motion due to the change of the supply voltage during the monitoring time period . Thus , the moveable part is not set in motion during the monitoring time period . Consequently, the switching device is not tripped since no motion of the magnetic drive is trans ferred to the contacts of the switching device .

[0036] Carrying out the method without tripping the switching device allows to carry out the method during operation of the switching device . This advantage allows to monitor the status of the freewheeling circuit of the switching device at regular intervals without interrupting an intended operation of the switching device .

[0037] For example , the method is carried out at regular intervals of 150 ms .

[0038] According to at least one embodiment of the method, the monitoring time period is controlled by a timer . The timer P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0039] 8 may be integrated in the control unit . The timer is in particular a watchdog timer .

[0040] In particular, the timer is started i f a starting signal for changing the supply voltage is provided . The starting signal may be provided by the control unit . For example , the starting signal is provided by the timer .

[0041] It is possible that the timer is reset by the inductive signal . Furthermore , an end signal for changing the supply voltage from the monitoring value to the operation value may be provided i f the timer is reset . The end signal may be provided by the control unit . For example , the end signal is provided by the timer . This means in particular that the timer is reset i f the inductive signal is detected . At the same time , the timer or the control unit preferably provide the end signal . The monitoring time period is in particular determined by a time period between the starting signal and the end signal .

[0042] By providing the end signal at the same time as resetting the timer and / or detecting the inductive signal , the monitoring time period can be particularly short . This allows the method to be carried out during operation of the switching device .

[0043] According to at least one embodiment , the freewheeling circuit comprises at least one freewheeling diode and at least one freewheeling switch arranged parallel to the freewheeling diode . I f the supply voltage having the operation value is supplied to the magnetic drive , the freewheeling switch is set in a first switching state overriding the freewheeling diode . I f the supply voltage having the monitoring value is supplied to the magnetic P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0044] 9 drive , the freewheeling switch is set in a second switching state applying voltage to the freewheeling diode .

[0045] The freewheeling switch is preferably controlled by the control unit . The freewheeling switch is in particular switched from the first switching state to the second switching state i f the starting signal is provided, i . e . at the beginning of the monitoring time period . The freewheeling switch is in particular switched from the second switching state to the first switching state i f the end signal is provided, i . e . at the end of the monitoring time period .

[0046] Furthermore , the freewheeling switch, in particular when a transistor is used for the freewheeling switch, may at least partially form the variable resistance by which the supply voltage of the solenoid can be varied, for example from the operation value to the monitoring value .

[0047] Furthermore , a switching device is speci fied . The switching device may use the method described herein in accordance with one or more embodiments during operation . This means that all features disclosed for the method are also disclosed for the switching device and vice versa .

[0048] In at least one embodiment , the switching device comprises a control unit and a freewheeling circuit arranged in series to a solenoid of a magnetic drive of the switching device . The switching device is in particular configured to be switched or tripped by interrupting a supply voltage supplying the solenoid . The control unit is in particular configured to control the supply voltage such that the supply voltage is changed from an operation value to a monitoring value for a monitoring time period . The freewheeling circuit comprises a P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0049] 10 monitoring unit configured to monitor an inductive signal induced in the freewheeling circuit .

[0050] For example , the supply voltage for the solenoid is provided by a voltage source . The supply voltage may, for example , be changed by changing the output of the voltage source .

[0051] However, preferably, the output of the voltage source is preferably constant , and the supply voltage is changed, for example from the operation value to the monitoring value or interrupted by a variable resistance or a switch . For example , the variable resistance can be implemented by using a transistor .

[0052] The freewheeling circuit of the switching device is in particular additionally provided for eliminating a voltage spike emerging i f the supply voltage is interrupted . Such an interruption in particular occurs i f the switching device is tripped . The switching device is in particular tripped i f the power line needs to be interrupted, for example in a safetyrelevant situation . I f the freewheeling circuit is not operating properly, the switching device cannot be tripped in a short period of time , which may cause safety problems .

[0053] In particular, the switching device is configured to carry out the method described herein . That is , a proper operation of the freewheeling circuit can be monitored and checked at regular intervals during operation of the switching device . Thus , mal functions of the switching device can be detected .

[0054] According to at least one embodiment of the switching device , the control unit comprises the timer . The timer is in particular configured to control the monitoring time period . For example , the timer is a watchdog timer . Preferably, the P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0055] - 11 - timer is configured to be started at the beginning of the monitoring time period . Further preferably, the timer is configured to be terminated at the end of the monitoring time period . The timer may be configured to be terminated by the inductive signal .

[0056] According to at least one embodiment of the switching device , the freewheeling circuit comprises at least one freewheeling diode and at least one freewheeling switch arranged in parallel to the freewheeling diode . In particular, the freewheeling switch is configured to bypass the freewheeling diode in a first switching state .

[0057] The freewheeling switch preferably is a semiconductor switch . For example , the freewheeling switch is a field-ef fect transistor such as a MOSFET . A gate electrode of the transistor may be connected to the control unit or the timer controlling a switching behavior of the freewheeling switch .

[0058] By the method described herein, the status of the freewheeling diode and the freewheeling switch can be monitored .

[0059] According to at least one embodiment , the switching device is an electronically driven electromagnetic switching device . For example , the switching device is a contactor .

[0060] Further advantages and advantageous embodiments and further developments of the method and the switching device described herein will become apparent from the following exemplary embodiments shown in connection with schematic drawings . Identical elements , elements of the same kind or elements having the same ef fect are provided with the same reference P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0061] - 12 - signs in the figures . The figures and the proportions of the elements shown in the figures are not to be regarded as true to scale . Rather, individual elements may be shown exaggeratedly large for better representability and / or for better comprehensibility .

[0062] In the figures :

[0063] Figure 1 shows a schematic representation of a switching device described herein according to an exemplary embodiment ;

[0064] Figure 2 shows a schematic circuit representation of a solenoid of a magnetic drive and a freewheeling circuit used in the switching device according to the exemplary embodiment ;

[0065] Figure 3 shows a block diagram illustrating a method described herein according to an exemplary embodiment .

[0066] Figure 1 illustrates a switching device 1 described herein according to an exemplary embodiment . The switching device 1 comprises fixed contacts 7 and corresponding moveable contacts 8 . The fixed contacts 7 and moveable contacts 8 comprise an electrically conductive material such as copper . The fixed contacts 7 are connected to a power line 70 that connects , for example , a power source on one end to a load on an opposing end .

[0067] The moveable contacts 8 are arranged on a contact bridge 80 of an electrically conductive material such as copper and / or steel . The contact bridge 80 is mechanically coupled to a moveable part 21 of a magnetic drive 2 by a contact spring 81 . P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0068] The moveable part 21 , which is also referred to as the anchor, comprises a magnetic material such as iron or ferrite . The magnetic drive 2 comprises a solenoid 20 wound around a fixed part 22 , which is also referred to as the core . The fixed part 22 comprises a magnetic material .

[0069] In a state of the switching device shown in Figure 1 , the moveable contacts 8 and the fixed contacts 7 contact each other . This means that the power line 70 is connected and the switching device 1 is "closed" . Furthermore , the moveable part 21 is in contact with the fixed part 22 . This is achieved by supplying the solenoid 20 with a supply voltage 10 . In particular, the supply voltage 10 has an operation value 11 in the closed state . Due to the supply voltage 10 the moveable part 21 is attracted to the fixed part 22 by magnetic interaction . Thereby, magnetic drive springs 23 are compressed .

[0070] At a tripping event from the closed state shown in Figure 1 to an open state , the supply voltage 10 is interrupted, i . e . the supply voltage 10 is set from the operation value 11 to a monitoring value 12 , wherein the monitoring value 12 is zero . Interrupting the supply voltage 10 causes the magnetic interaction between the fixed part 22 and the moveable part 21 to vanish, and the moveable part 21 is set in motion due to decompression of the magnetic drive springs 23 . Since the contact bridge 80 is mechanically coupled to the moveable part 21 , the contacts 7 , 8 of the switching device 1 are separated and the power line 70 is interrupted . Hence , the switching device 1 is "open" . P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0071] - 14 -

[0072] The switching device 1 comprises a control unit 4 , which is configured to control the supply voltage 10 . The control unit 4 is , for example , a microcontroller . Thus , the control unit 4 is configured to trip the switching device 1 . The control unit 4 receives and sends data via a data line 40 .

[0073] The switching device 1 further comprises a freewheeling circuit 3 arranged in series to the solenoid 20 as also illustrated in Figure 2 . The freewheeling circuit 3 comprises a freewheeling switch 32 and two freewheeling diodes 31 . The freewheeling diodes 31 are arranged in parallel to the freewheeling switch 32 . The freewheeling switch 32 bypasses the freewheeling diodes 31 in a first switching state , in which the solenoid 20 is supplied with the supply voltage 10 having the operation value 11 . I f the value of the supply voltage 10 is changed or interrupted, the freewheeling switch 32 switches to a second state , providing the freewheeling diodes 31 with voltage . The supply voltage 10 is supplied by a voltage source 25 , which is in particular a DC voltage source . The freewheeling circuit 3 and the control unit 4 are arranged in a housing 15 of the switching device 1 .

[0074] The output of the voltage source 25 is preferably constant , and the supply voltage 10 is changed, for example from the operation value 11 to the monitoring value 12 by a variable resistance . For example , the variable resistance is implemented by using a transistor such as the freewheeling switch 32 . The variable resistance is preferably controlled by the control unit 4 .

[0075] The freewheeling circuit 3 of the switching device 1 is in particular provided for eliminating a voltage spike emerging i f the supply voltage 10 is interrupted . Such an interruption P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0076] 15 in particular occurs i f the switching device 1 is tripped . The switching device 1 is in particular tripped i f the power line 70 needs to be interrupted, for example in a safetyrelevant situation . I f the freewheeling circuit 3 is not operating properly, the switching device 1 cannot be tripped in a short period of time , which may cause safety problems .

[0077] The switching device 1 described herein is capable of carrying out a method for monitoring the switching device 1 , in particular the freewheeling circuit 3 illustrated in Figure 3 . In the blocks illustrating each method steps , the value of the supply voltage 10 for the solenoid 20 in each step is shown .

[0078] In a method step 101 a starting signal 60 is provided . The starting signal 60 is provided by the control unit 4 or a timer 6 of the control unit 4 ( cf . Figure 1 ) . The timer 6 is configured to monitor the timing of the method and is a watchdog timer .

[0079] By providing the starting signal 60 the timer 6 is started and a monitoring time period 13 is started .

[0080] In a step 102 the control unit 4 changes the supply voltage 10 from the operation value 11 to a monitoring value 12 . The monitoring value 12 is smaller than the operation value 11 . Preferably, the monitoring value 12 is zero . Changing the supply voltage 10 causes an inductive signal 30 to be generated in the freewheeling circuit 3 . The inductive signal 30 is an inductive voltage emerging due to discharging the inductance of the solenoid 20 . In particular, the inductive voltage is larger than the operation value 11 of the supply voltage 10 . P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0081] In step 103 the inductive signal 30 is detected by a monitoring unit 5 of the freewheeling circuit 3 . The monitoring unit 5 comprises a voltage measurement device detecting a voltage at a resistance 35 of the freewheeling circuit 3 ( cf . Figure 2 ) .

[0082] In step 104 the inductive signal 30 is provided to the control unit 4 and in particular to the timer 6 . The timer 6 is therefore connected to the monitoring unit 5 ( cf . Figure 1 ) . As a response to receiving the inductive signal 30 , the timer 6 stops , is reset , and provides an end signal 61 . The end signal 61 terminates the monitoring time period 13 .

[0083] In step 105 the control unit 4 sets the supply voltage 10 back to the operation value 11 .

[0084] It is thus possible by the method comprising steps 101 to 105 to monitor the status of the freewheeling circuit 3 . It is possible that steps 101 to 105 are carried out multiple times at regular intervals .

[0085] Preferably, the monitoring time period 13 is smaller than a staring time period of the moveable parts of the switching device 1 . For example , the moveable part 21 of the magnetic drive 2 moves with respect to the fixed part 22 of the magnetic drive 2 after the starting time period . The starting time period in particular starts at the same point in time as the monitoring time period 13 . This means that the starting time period starts when the supply voltage 10 is changed to the monitoring value 12 . The starting time period represents a lag time it takes for the moveable part 21 to start moving due to mechanical inertia of the moveable part 21 . P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0086] Since the monitoring time period 13 is shorter than the starting time period, the monitoring time period 13 ends before the moveable part is set in motion . In other words , the magnetic drive 2 is already supplied with the supply voltage 10 having the operation value 11 before the moveable part 21 is set in motion due to the change of the supply voltage 10 during the monitoring time period 13 . Thus , the moveable part 21 is not set in motion during the monitoring time period 13 . Consequently, the switching device 1 is not tripped since no motion of the magnetic drive 2 is trans ferred to the contact bridge 80 of the switching device 1 . As a result , the method steps 101 to 105 can be carried out during operation of the switching device 1 .

[0087] Advantageously, the method comprising steps 101 to 105 allows to monitor the status of the electronics , i . e . the freewheeling circuit 3 of the switching device 1 , at regular intervals during operation of the switching device 1 . Thus , a reliability of the switching device 1 can be increased .

[0088] The invention is not restricted to the exemplary embodiments by the description on the basis of said exemplary embodiments . Rather, the invention encompasses any new feature and also any combination of features , which in particular comprises any combination of features in the patent claims and any combination of features in the exemplary embodiments , even i f this feature or this combination itsel f is not explicitly speci fied in the patent claims or exemplary embodiments . P2024 , 0610 WO N / P24- 1234WO01 August 4 , 2025

[0089] - 18 -

[0090] References

[0091] 1 switching device

[0092] 2 magnetic drive

[0093] 3 freewheeling circuit

[0094] 4 control unit

[0095] 5 monitoring unit

[0096] 6 timer

[0097] 7 fixed contact

[0098] 8 moveable contact

[0099] 10 supply voltage

[0100] 11 operation value of supply voltage

[0101] 12 monitoring value of supply voltage

[0102] 13 monitoring time period

[0103] 15 housing

[0104] 20 magnetic drive solenoid

[0105] 21 moveable part of magnetic drive

[0106] 22 fixed part of magnetic drive

[0107] 23 magnetic drive spring

[0108] 25 voltage source of magnetic drive

[0109] 30 inductive signal

[0110] 31 freewheeling diode

[0111] 32 freewheeling switch

[0112] 35 resistance

[0113] 40 data line

[0114] 60 starting signal

[0115] 61 end signal

[0116] 70 power line

[0117] 80 contact bridge

[0118] 81 contact spring

[0119] 101 . . . 105 method steps

Claims

P2024,0610 WO N / P24-1234WO01 August 4, 2025Claims1. Method for monitoring a switching device (1) configured to switch by changing a supply voltage (10) for a solenoid of a magnetic drive (2) , and comprising a freewheeling circuit (3) arranged in series to the solenoid (20) of the magnetic drive (2) , the method comprising the steps of:- changing the supply voltage (10) of the solenoid (20) from an operation value (11) to a monitoring value (12) for a monitoring time period (13) ,- monitoring an inductive signal (30) induced in the freewheeling circuit (3) during the monitoring time period ( 13 ) .

2. Method according to claim 1, wherein the monitoring value (12) of the supply voltage (10) is zero, and wherein the supply voltage (10) is controlled by a control unit (4) .

3. Method according to claim 1 or 2, wherein the inductive signal (30) is an inductive voltage monitored by a monitoring unit (5) comprising a voltage comparing device .

4. Method according to claim 3, wherein the inductive voltage is greater than the supply voltage (10) .

5. Method according to one of the preceding claims, wherein the method is carried out during operation of the switching device (1) without tripping the switching device ( 1 ) .P2024,0610 WO N / P24-1234WO01 August 4, 2025- 20 -6. Method according to one of the preceding claims, wherein a moveable part (21) of the magnetic drive (2) moves with respect to a fixed part (22) of the magnetic drive (2) after a starting time period starting at the same (point in) time as the monitoring time period (13) , and the monitoring time period (13) is shorter than the starting time period.

7. Method according to one of the preceding claims, wherein the monitoring time period (13) is controlled by a timer (6) .

8. Method according to claim 7, wherein the timer (6) is started if a starting signal (60) for changing the supply voltage (10) from the operation value (11) to the monitoring value (12) is provided.

9. Method according to claim 7 or 8, wherein the timer (6) is reset by the inductive signal (30) , and wherein an end signal (61) for changing the supply voltage (10) from the monitoring value (12) to the operation value (11) is provided if the timer (6) is reset .

10. Method according to one of the preceding claims, wherein the freewheeling circuit (3) comprises at least one freewheeling diode (31) and at least one freewheeling switch (32) arranged in parallel to the freewheeling diode ( 31 ) , wherein, if the operation value (11) of the supply voltage (10) is supplied to the magnetic drive (2) , the freewheeling switch (32) is set in a first switching state overriding the freewheeling diode (31) , andP2024,0610 WO N / P24-1234WO01 August 4, 2025 wherein, if the monitoring value (12) is supplied to the magnetic drive (2) , the freewheeling switch (32) is set in a second switching state applying voltage to the freewheeling diode (31) .

11. Switching device (1) comprising a control unit (4) , and a freewheeling circuit (3) arranged in series to a solenoid (20) of a magnetic drive (2) , wherein- the switching device (1) is configured to be switched by interrupting a supply voltage (10) supplying the solenoid (20) ,- the control unit (4) is configured to control the supply voltage (10) such that the supply voltage (10) is changed from an operation value (11) to a monitoring value (12) for a monitoring time period (13) ,- the freewheeling circuit (3) comprises a monitoring unit (5) configured to monitor an inductive signal (30) induced in the freewheeling circuit (3) .

12. Switching device (1) according to claim 1, wherein the control unit (4) comprises a timer (6) , and the timer (6) is configured to control the monitoring time period (13) .

13. Switching device (1) according to claim 11 or 12, wherein the freewheeling circuit (3) comprises at least one freewheeling diode (31) and at least one freewheeling switch (32) arranged in parallel to the freewheeling diode (31) , wherein the freewheeling switch (32) is configured to override the freewheeling diode (31) in a first switching state.P2024,0610 WO N / P24-1234WO01 August 4, 2025- 22 -14. Switching device (1) according to one of claims 11 to13, wherein the switching device (1) is an electronically driven electromagnetic switching device.

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