STATUS DETECTION CIRCUIT AND REMOTE OPERATED SWITCH

Description

[0001] The invention relates to state detection circuits, e.g. for remotely operated switches, and remotely operated switches with a corresponding state detection circuit.

[0002] Remotely operated switches are circuit elements that can establish or break an electrical contact between electrodes as desired. Furthermore, it is possible to control the switching state remotely.

[0003] Relays and contactors offer ways to implement such remotely operated switches.

[0004] To monitor their function, it is generally desirable not only to control the switching state but also to output it, for example to recognize the difference between the actual switching state and the target switching state in case of a fault.

[0005] From WO 2017 / 129823 A1, relays are known which have a read contact that is intended to communicate the switching state of the relay to an external circuit environment.

[0006] From WO 2020 / 043515 A1, power contactors are known whose circuit for communicating the switching state includes a Hall switch.

[0007] From US 4,450,427 A, a contactor is known in whose immediate vicinity a Hall sensor is arranged. The Hall sensor is used to detect small variations in the magnetic flux of the contactor and to compensate for these by adjusting the applied voltage.

[0008] US 2020 / 365 346 A1 shows an interrupt circuit.

[0009] CN 103 954 820 B shows a self-test device.

[0010] US 5 694 341 A shows a Hall sensor located in the vicinity of the rotating magnet, designed to detect a number of rotations.

[0011] Remotely operated switches, such as contactors, generally have a control circuit that can switch a load circuit on and off. One possible use for such contactors is to establish or disconnect the electrical connection between a battery and an electric motor, for example, in an electric vehicle. In this way, the contactor can function as a safety component, disconnecting the source and load (i.e., the battery and electric motor) in the event of a malfunction, especially at high voltages, such as 450 V.

[0012] Remote-controlled switches, such as those described in the aforementioned publications, are typically designed for an operating voltage of 5 V. Furthermore, their current draw is relatively high. Additionally, there is a risk of damaging the electronics if the connecting wires are reversed. The electronics can also be destroyed by electrostatic discharge and voltage surges.

[0013] Furthermore, while read contacts are a simple solution for outputting the switching state, their reliability, especially in the presence of other external magnetic fields, can be improved.

[0014] Known remote-controlled switches with Hall effect sensors exhibit the aforementioned disadvantages.

[0015] Therefore, there is a desire to improve the reliability of switching state detection circuits. In particular, there is a need for state detection circuits and corresponding remotely operated switches that exhibit increased reliability without requiring special adaptation of the external circuit environment to the improved remote switches. Furthermore, there is also a desire for remotely operated switches with reduced power consumption.

[0016] This includes a state detection circuit or a remotely actuated switch with a state detection circuit according to independent claim 1 and the dependent claim. Dependent claims specify advantageous embodiments.

[0017] The state detection circuit comprises a Hall sensor circuit with a Hall sensor. Furthermore, the state detection circuit has a voltage regulator and an output switch. The Hall sensor circuit is connected between the voltage regulator and the output switch.

[0018] With this circuit configuration consisting of a Hall sensor circuit, voltage regulator, and output switch, it is possible to specify a state detection circuit that can operate not only for a fixed 5 V supply voltage but also for a wide voltage range. Furthermore, the current consumption is significantly reduced compared to known state detection circuits. While the current consumption of a state detection circuit according to WO 2020 / 043515 A1 can be up to 20 mA, the present state detection circuit may have a maximum current consumption of 5 mA or less, e.g., 2.4 mA.

[0019] The voltage regulator allows an external supply voltage to power the state detection circuit. The output switch can communicate the switching state, e.g., of a connected remote-controlled switch, to an external circuit environment.

[0020] Furthermore, it is possible to configure the connecting lines in such a way that the reverse polarity protection of the electronics of the state detection circuit is improved and is therefore not damaged even in the event of incorrect wiring with an external circuit environment.

[0021] Furthermore, it is possible to configure the sensitive components of the condition detection circuit in such a way that the electronics are not destroyed by electrostatic charging and / or overvoltage pulses.

[0022] The state detection circuit described above differs fundamentally from detection circuits such as those known from WO 2020 / 043515 A1. WO 2020 / 043515 A1, for example, shows state detection circuits in which an operational amplifier 203 is connected between a Hall sensor 19 and a semiconductor switch 207.

[0023] In contrast, the state detection circuit, as described above, specifies a configuration in which the Hall sensor, which is part of a Hall circuit, is connected between the voltage regulator and the output switch.

[0024] Furthermore, there is no equivalent for the voltage regulator of the present state detection circuit in the detection circuit of WO 2020 / 043515 A1, and no equivalent for operational amplifier 203 of WO 2020 / 043515 A1 in the state detection circuit as described above. The state detection circuit as described above is therefore fundamentally different from the circuit topology of the detection circuit of WO 2020 / 043515 A1.

[0025] Because the state detection circuit, as described above, can be operated with a wide range of supply voltages, it is universally applicable. This allows it to replace existing detection circuits without additional development effort, thereby improving remotely operated switches and reducing power consumption. The supply voltage range can be, for example, 4 V or more and 36 V or less.

[0026] The Hall sensor provides a binary output signal.

[0027] The circuit configuration with the Hall sensor circuit between the voltage regulator and the output switch allows the use of a Hall sensor that generates a binary output signal. The Hall sensor of WO 2020 / 043515 A1 is designed to supply a current between 5 and 7 mA for one switching state. To indicate the other switching state, the Hall sensor outputs a current between 12 mA and 17 mA. The Hall sensor of WO 2020 / 043515 A1 is therefore a current source with relatively high power consumption, while the binary output signal of the Hall sensor, according to the present state detection circuit, is easier for subsequent circuit elements to evaluate and allows for lower energy consumption.

[0028] It is possible that the state detection circuit also includes an output terminal. The output switch is then designed and, of course, appropriately suited to provide a switching state of a remotely operated switch according to the magnetic environment of the Hall sensor at the output terminal.

[0029] The Hall sensor uses the Hall effect, i.e., it detects the magnetic environment of the Hall sensor.

[0030] Remotely operated switches, such as relays or contactors, generally have a first electrode and a second electrode, as well as an electrical conductor whose position within the remotely operated switch can be varied. Specifically, the electrical conductor can be mechanically connected to the two electrodes to electrically link them and mechanically disconnected from at least one of them to break the electrical connection. A magnet can be mechanically connected to the electrical conductor of the remotely operated switch, changing its position according to the switching state, analogous to the electrical conductor. The Hall sensor is fixed relative to the remotely operated switch, so that when the switching state changes, the distance between the magnet and a sensitive area of ​​the Hall sensor also changes.This means that when the remote-controlled switch is activated, the magnetic environment of the Hall sensor changes. This information, which corresponds to the switching state of the associated remote-controlled switch, can then be made available to an external circuit environment at the output terminal of the state detection circuit.

[0031] The use of a Hall sensor has the advantage that the Hall sensor operates without mechanical wear, which improves the reliability and lifespan of the condition detection circuit.

[0032] The state detection circuit may also have a power supply connection and a ground connection. A supply voltage can be provided to the state detection circuit via the power supply connection. The state detection circuit can be connected to the ground potential of an external circuit environment via the ground connection.

[0033] Due to the configuration of the state detection circuit with the Hall sensor circuit between the voltage regulator and the output switch, the supply connection may be suitable for accepting a wide range of supply voltages to function correctly. It is possible that any voltage between 4 V and 36 V is sufficient to operate the state detection circuit.

[0034] It is possible that the Hall sensor is connected to three different lines of the Hall sensor circuit.

[0035] The configuration in which the Hall sensor is connected to three different lines of the Hall sensor circuit thus represents a circuit environment for the Hall sensor that differs significantly from the circuit environment around the Hall sensor of WO 2020 / 043515 A1. Figure 3B of WO 2020 / 043515 A1 clearly shows that the Hall sensor 19 is connected to exactly two lines of its circuit environment.

[0036] The condition detection circuit described above thus represents a new and improved configuration that increases reliability and reduces power consumption. It is possible that the Hall sensor is connected to ground and to the output switch, and furthermore electrically coupled to an output of the voltage regulator.

[0037] The connection to ground and to the output switch can be a direct connection. This means that the Hall sensor is possible to be directly connected to ground and directly to the output switch.

[0038] It is possible that the Hall sensor circuit also includes a resistive element and a capacitive element. The resistive element can be connected between an output of the voltage regulator and the first terminal of the Hall sensor. The capacitive element can also be connected between the first terminal of the Hall sensor and ground.

[0039] The first resistive element can have a resistance between 50 Ω and 150 Ω, e.g., 100 Ω. The capacitive element can have a capacitance between 5 nF and 15 nF, e.g., 10 nF. The capacitive element can have a rated voltage of 50 V and thus operate without problems in the voltage range between 5 V and 50 V.

[0040] It is possible that the resistive element and the capacitive element together form a section of an RC filter. This filter can reduce ripple in the voltage regulator's supply voltage and thus smooth the Hall sensor's supply voltage.

[0041] It is possible that the state detection circuit also includes a first diode. This first diode can be connected between the supply terminal and an input of the voltage regulator.

[0042] The first diode can be a reverse polarity protection diode, which protects the state detection circuit against damage in case of incorrect polarity. This reverse polarity protection can be enabled up to a voltage of 60 V. The forward voltage can be 0.5 V. The continuous current rating can be 30 mA and the maximum short-term current rating can be 2 A.

[0043] It is possible that the state detection circuit also includes a first diode circuit between the output terminal and ground.

[0044] The first diode circuit can comprise two diodes connected in series and facing in opposite directions. This first diode circuit can have a breakdown voltage of 40 V. The first diode circuit can protect the output switch from overvoltage.

[0045] Furthermore, it is possible that the state detection circuit includes a second diode circuit. This second diode circuit can be connected between ground and the power supply terminal.

[0046] The second diode circuit can also have two diodes arranged in opposite directions and connected in series.

[0047] The second diode circuit can have a breakdown voltage of 40 V. This second diode circuit can be configured as a bidirectional TVS diode. Upon reaching its breakdown voltage, the second diode circuit can conduct and create a short circuit to protect the downstream circuit components from overvoltage. The state detection circuit is thus reliably protected against reverse polarity.

[0048] It is possible that the state detection circuit also includes a second resistive element. This second resistive element can be connected between the first and second terminals of the Hall sensor.

[0049] The second resistive element can act as a pull-up resistor for the Hall sensor and have a resistance between 50 kΩ and 150 kΩ, for example, 100 kΩ. This second resistive element can serve to stabilize the output signal of the Hall sensor.

[0050] Furthermore, it is possible that the state detection circuit includes a third resistive element. This third resistive element can be connected between ground and the output switch.

[0051] The third resistive element can have a resistance between 100 Ω and 200 Ω, for example, 150 Ω. The output switch can be coupled to ground via this third resistive element, ensuring that its electrical potential is well-defined relative to ground potential.

[0052] It is possible that the output switch includes a semiconductor switch and / or a protected semiconductor switch.

[0053] The semiconductor switch can be a field-effect transistor (FET).

[0054] The semiconductor switch can have an operating voltage of 4 V to 60 V and is designed to forward the switching state information to an external circuit environment depending on the output signal of the Hall sensor, without the Hall sensor being directly connected to the external circuit environment.

[0055] In addition to the semiconductor switch itself, the output switch can incorporate further protective elements that safeguard the semiconductor switch against impermissible operating parameters, such as excessive currents or voltages. This means the output switch can be, or include, a so-called protected FET (ProFET).

[0056] It is possible that the voltage regulator is designed and suitable to provide an output voltage between 3 V and 15 V from an input voltage between 4 V and 36 V. The output voltage of the voltage regulator can, in particular, be 5 V. The voltage regulator essentially supplies the Hall sensor circuits with electrical power.

[0057] It is possible that the Hall sensor in the Hall sensor circuit comprises a semiconductor switch and a Hall element connected to the gate terminal of the semiconductor switch. The semiconductor switch of the Hall sensor could also be a field-effect transistor.

[0058] This configuration, in which the Hall sensor is connected to its circuit environment via three wires, distinguishes the configuration of the present condition detection circuit from corresponding detection circuits, for example WO 2020 / 043515 A1.

[0059] Furthermore, it is possible that the state detection circuit includes a second capacitive element. This second capacitive element can be connected between the power supply terminal and ground.

[0060] The second capacitive element can have a capacitance between 50 nF and 150 nF, for example 100 nF, and acts as a smoothing capacitor to absorb high voltage spikes at the supply terminal of the state detection circuit. When the second capacitive element is sufficiently charged, the second diode circuit can then switch on and dissipate voltage spikes to ground.

[0061] A corresponding remotely operated switch can include an electrical switch and a state detection circuit, for example as described above. The state detection circuit is designed and, due to its specific configuration, capable of reliably detecting the switching state of the electrical switch and transmitting this information to an external circuit environment.

[0062] It is possible that the remotely operated switch is selected from a relay, a contactor, and a high-voltage contactor.

[0063] It is possible that the status detection circuit of the remotely operated switch provides information on whether the switching state of the switch is "closed as intended" and / or "open as intended".

[0064] This makes it clear whether the actual switching state matches the intended switching state as planned, or whether there is a fault and the switch does not have an intended switching state (open or closed), but is open when it should be closed, closed when it should be open, or has a state that is neither fully closed nor fully open.

[0065] The circuit elements of the state detection circuit can be arranged on one or both sides of a circuit board. The circuit board can be located in the base of the remote-controlled switch. Furthermore, the circuit board can have dimensions such that it fits into conventional remote-controlled switches. In particular, the circuit board can be circular and have a diameter between 10 and 15 mm, for example, 8.5 mm, 12.5 mm, or 13.9 mm. Operating principles and details of preferred embodiments are shown in more detail in the following schematic figures.

[0066] It is possible that the remotely operated switch (FS) also includes a marking on an electrical conductor. The conductor is designed and suitable for connecting the switch to an external circuit environment.

[0067] It is also possible that the conductor is a connecting cable and the marking is a warning label to warn against reverse polarity. Such a marking represents one possible configuration that improves reverse polarity protection.

[0068] In particular, they show: Figure 1 the arrangement of some circuit blocks relative to each other, Figure 2 the circuit diagram with further circuit elements of a preferred embodiment, Figure 3 the circuit environment of the Hall element in the Hall sensor, Figure 4 Functional elements of a remote-controlled switch. Fig. 5 Circuit elements of another preferred embodiment.

[0069] Figure 1This diagram shows blocks of the state detection circuit ZES. The state detection circuit comprises a voltage regulator SR, a Hall sensor circuit HSS, and an output switch AS. The Hall sensor circuit includes a Hall sensor HS. The Hall sensor circuit HSS is connected between the voltage regulator SR and the output switch AS. The state detection circuit also has an input SUP for a supply voltage and an output OUT to transmit the switching state to an external circuit. The output switch AS is connected between the Hall sensor circuit HSS and the output terminal OUT. Optionally, the output switch AS can be connected to the supply terminal SUP.

[0070] The arrow directions at the SUP power supply terminal and the OUT output terminal indicate the direction of the corresponding electrical power.

[0071] The configuration with the Hall sensor circuit and its Hall sensor between the voltage regulator and the output switch fundamentally differs the state detection circuit from corresponding state detection circuits in known remote-controlled switches. As a result of the new configuration, the state detection circuit can exhibit lower power consumption and increased reliability while remaining compatible with existing remote-controlled switches.

[0072] Figure 2 Figure 1 shows an embodiment of the ZES state detection circuit with additional circuit elements. For example, there is an additional connection that can be connected to ground potential. In particular, the voltage regulator SR, the Hall sensor circuit HSS, and the output switch AS can be connected to ground.

[0073] In the HSS Hall sensor circuit, the first terminal HS1 of the HS Hall sensor is connected via a first resistive element R1 to the first output terminal SR1 of the voltage regulator SR. A second terminal HS2 of the HSS Hall sensor circuit is connected to an input of the output switch AS. Another terminal of the HS Hall sensor is connected to ground.

[0074] The first capacitive element C1 is connected between the first terminal HS1 of the Hall sensor HS and ground. The pull-up resistor R2 is connected between the first terminal HS1 and the second terminal HS2 of the Hall sensor HS.

[0075] The first diode D1 is connected between the power supply terminal SUP and the voltage regulator SR. The first diode D1 acts as a reverse polarity protection diode against incorrect polarity of the state detection circuit.

[0076] The first diode circuit, DS1, is connected between the output terminal OUT and ground. DS1 provides overvoltage protection. In particular, DS1 can protect the output switch AS from overvoltage.

[0077] The second diode circuit, DS2, is connected between the supply terminal SUP and ground. DS2 protects the downstream circuit components from overvoltage at the SUP supply terminal. Voltage spikes are shunted to ground when the breakdown voltage of DS2 is exceeded.

[0078] The third resistive element R3 is connected between ground and the output switch AS and provides the output switch AS with a defined potential relative to ground.

[0079] Figure 3Figure 1 shows a possible internal structure of the HS Hall sensor. This structure can include a Hall element HE and a semiconductor switch HLS. The Hall element HE is positioned near the rest position of a magnet on the movable electrical conductor of the remotely actuated switch and detects magnetic fields in its vicinity. The Hall element HE is connected to the base of the semiconductor switch HLS. The HS Hall sensor is connected to its circuit environment via three wires and provides a binary output signal at its output, via the semiconductor switch HLS, indicating the magnetic environment of the Hall element. The semiconductor switch HLS of the HS Hall sensor is essentially coupled to, or directly connected to, the output switch AS.

[0080] Figure 4Figure 1 shows the key elements of a remotely operated switch FS. The remotely operated switch FS has a first electrode EL1 and a second electrode EL2, as well as an electrical conductor L. The electrical conductor L can be attached to a push element SCH. The electrical conductor can be pressed against or pulled away from the first electrode EL1 and the second electrode EL2 via the push element SCH, for example, by means of magnetic coils MS. This allows the remotely operated switch to close or open an electrical contact between the electrodes EL1 and EL2. The magnetic coils MS can be remotely controlled by corresponding currents. A magnet M is permanently connected to the push element SCH and changes its position depending on the position of the electrical conductor L, thereby altering the magnetic environment of the Hall sensor HS.Based on its magnetic environment, the Hall sensor HS can transmit a binary signal regarding the switching state of the electrical conductor L to the external circuit environment. The circuit elements or circuit blocks of the state detection circuit can be arranged on one or both sides of a printed circuit board (PCB) LP, which is connected to the Hall sensor HS. The PCB LP can be positioned and mounted in the base of the remotely operated switch FS. The PCB LP can be sized and shaped to fit into corresponding recesses in standard remotely operated switches FS. This allows for a reduction in the power consumption and an increase in the reliability of standard remotely operated switches without requiring modifications to the other switching elements of the switch ES.

[0081] Figure 5 shows a preferred form of a state detection circuit based on the circuit according to the Figure 2based. Thus, compared to the circuit of the Figure 2 - the output switch of the circuit according to the Figure 5 It is connected directly to ground instead of to the supply terminal Sup. Furthermore, the circuit lacks the following features: Figure 5 the third resistive element R3 and the output switch of the circuit according to Figure 5 the associated circuit via R3 to ground. The first diode D1 of the circuit according to Figure 2 is in the embodiment according to the Figure 5 no longer included.

[0082] The resistance value of the second resistive element R2 can be between 2 kΩ and 10 kΩ, e.g., 4.7 kΩ. The output switch AS can be implemented as a three-pole (semiconductor) switch, e.g., as a protected FET.

[0083] The state detection circuit and the remotely operated switch are not limited to the described embodiments. The state detection circuit can include further circuit elements, for example, for detecting the temperature or a voltage applied to the housing of the corresponding switch to detect a fault. Reference symbol list

[0084] AS Output switch C1 First capacitive element C2 Second capacitive element D1 First diode DS1 First diode circuit DS2 Second diode circuit EL1 First electrode of remote-controlled switch EL2 Second electrode of remote-controlled switch ES Electrical switch of remote-controlled switch FS Remote-controlled switch HE Hall element HLS Semiconductor switch HS Hall sensor HS1 First output of Hall sensor HS2 Second output of Hall sensor HSS Hall sensor circuit L Movable electrical conductor LP Printed circuit board M Magnet MS Magnetic coil OUT Output terminal R1 First resistive element R2 Second resistive element R3 Third resistive element SCH Push element SR Voltage regulator SR1 First output of voltage regulator SUP Supply terminal ZES State detection circuit

Claims

1. State detection circuit (ZES), comprising - a Hall sensor circuit (HSS) with a Hall sensor (HS), - a voltage regulator (SR) and - an output switch (AS), wherein the Hall sensor circuit (HSS) is connected between the voltage regulator (SR) and the output switch (AS), wherein the Hall sensor (HS) is designed to be arranged in such a way that a magnetic environment of the Hall sensor (HS) changes when a remotely actuatable switch (FS) is activated, characterized in that the Hall sensor (HS) is designed to provide a binary output signal relating to a magnetic environment of the Hall sensor (HS), and in that the output switch (AS) is provided to forward an item of switching state information concerning the remotely actuatable switch (FS) to an external circuit environment depending on the output signal of the Hall sensor (HS).

2. State detection circuit (ZES) according to Claim 1, further comprising an output connection (OUT), wherein the output switch (AS) is provided to provide a switching state of a remotely actuated switch (FS) according to the magnetic environment of the Hall sensor (HS) at the output connection (OUT).

3. State detection circuit (ZES) according to either of the preceding claims, further comprising a supply connection (SUP) and an earth connection (GND).

4. State detection circuit (ZES) according to one of the preceding claims, wherein the Hall sensor (HS) is connected to three different lines of the Hall sensor circuit (HSS).

5. State detection circuit (ZES) according to the preceding claim, wherein the Hall sensor (HS) - is connected to earth (GND) and the output switch (AS) and - is electrically coupled to an output (SR1) of the voltage regulator (SR).

6. State detection circuit (ZES) according to one of the preceding claims, wherein - the Hall sensor circuit (HSS) further comprises a resistive element (R1) and a capacitive element (C1) and - the resistive element (R1) is connected between an output (SR1) of the voltage regulator (SR) and a first connection (HS1) of the Hall sensor (HS) and - the capacitive element (C1) is connected between the first connection (HS1) of the Hall sensor (HS) and earth (GND) .

7. State detection circuit (ZES) according to one of the preceding claims, further comprising a first diode (D1) between the supply connection (SUP) and an input of the voltage regulator (SR).

8. State detection circuit (ZES) according to one of the preceding claims, further comprising a first diode circuit (DS1) between the output connection (OUT) and earth (GND).

9. State detection circuit (ZES) according to one of the preceding claims, further comprising a second diode circuit (DS2) between earth (GND) and the supply connection (SUP).

10. State detection circuit (ZES) according to one of the preceding claims, further comprising a second resistive element (R2) between the first connection (HS1) of the Hall sensor (HS) and the second connection (HS2) of the Hall sensor (HS).

11. State detection circuit (ZES) according to one of the preceding claims, further comprising a third resistive element (R3) between earth (GND) and the output switch (AS).

12. State detection circuit (ZES) according to one of the preceding claims, wherein the output switch comprises a semiconductor switch and / or a protected semiconductor switch.

13. State detection circuit (ZES) according to one of the preceding claims, wherein the voltage regulator is provided and suitable for providing an output voltage that is between 3 V and 15 V or is 5 V for an input voltage of between 4 V and 36 V.

14. State detection circuit (ZES) according to one of the preceding claims, wherein the Hall sensor (HS) comprises a semiconductor switch (HLS) and a Hall element (HE) that is connected to the gate connection of the semiconductor switch.

15. State detection circuit (ZES) according to one of the preceding claims, further comprising a second capacitive element (C2) that is connected between the supply connection (SUP) and earth (GND).

16. Remotely actuatable switch (FS), comprising - an electrical switch (ES) and a state detection circuit (ZES), according to one of the preceding claims, which is provided for providing a switching state of the electrical switch (ES).

17. Remotely actuatable switch (FS) according to the preceding claim, which is selected from a relay, a contactor and a high-voltage contactor.

18. Remotely actuatable switch (FS) according to either of the two preceding claims, in which the state detection circuit provides information as to whether the switching state of the switch is "closed as intended" and / or "open as intended".

19. Remotely actuatable switch (FS) according to one of the three preceding claims, further comprising a marking on an electrical conductor that is provided and suitable for connecting the switch to an external circuit environment.

20. Remotely actuatable switch (FS) according to one of the four preceding claims, wherein the conductor is a connection line and the marking is a warning label for warning against polarity reversal.