Apparatus and method for monitoring turn-off capability

Abstract

The present disclosure relates to a device and a method for monitoring turn-off capability. The device is suitable for monitoring the turn-off capability of an electrical consumer connected to a first current path, in which a first electrical regulating element is arranged, the current passing capacity of which can be changed by a first regulating signal and is characterized by a first electrical parameter (capacitive capacity or voltage ascertained by a voltage measuring device). The device is further provided with a second regulating element in a second current path for providing the first regulating signal, the current passing capacity of which can be changed by a second regulating signal and is characterized by a second electrical parameter (capacitive capacity or voltage). The two capacitive capacities are connected in series, the control device operates the second regulating element by means of the second regulating signal and evaluates the value of the first electrical parameter in order to identify a fault in the first regulating element, said evaluation comprising a comparison of said value with at least one reference predetermined value.

Description

Technical Field

[0001] This disclosure relates to an apparatus for monitoring the turn-off capability of a consumer, particularly through a switching element. Furthermore, this disclosure also relates to a method for monitoring turn-off capability, as well as a control device, a system, and a computer program. Background Technology

[0002] A typical challenge for such devices may be the ability to diagnose the turn-off capability of digital outputs when they are in the ON state, especially when coupled to a load.

[0003] In fields such as those conforming to SIL standard IEC 61508 and performance levels according to IEC 13849, safety functions should provide a very high probability, according to their specifications, to prevent injury to third parties, irreversible damage, and fatal accidents. It should be possible to ensure that safe digital outputs can be shut off with a high probability.

[0004] Measures and methods for diagnosing turn-off capability are known in the prior art. Turn-off can be configured to be performed periodically, for example, within a time range of 1 ms to every 500 ms. In practical applications, such periodic turn-off can be detrimental to the function of the switching element. Therefore, it may be necessary to diagnose turn-off capability and ensure a high probability of turn-off when it is not required.

[0005] Several methods have been proposed in the prior art. DE 10 2020 113 822 A1 demonstrates a safe output terminal in which the output switching elements do not need to be periodically turned off for testing because these elements are located in a regulation loop through which their functionality can be monitored. The main drawback of this solution is that when the output switching elements are in the regulation loop and the voltage drop across the semiconductor segment is higher than the voltage drop in the fully controlled on state, the output switching elements cannot be fully controlled to conduct. This results in unnecessary heat generation from the switching elements. Furthermore, the regulation loop design is complex and requires numerous components, which in turn leads to a larger circuit board and higher cost.

[0006] US 007 702 302B1 illustrates an interconnect circuit that includes a FET and a measuring resistor for current measurement within a power supply mechanism. A disadvantage of US 007 702 302B1 is the inability to periodically test the FET in the on-state, thus hindering the achievement of a high level of safety. Furthermore, the measuring resistor is connected in the power path, potentially causing power loss.

[0007] US2012 / 0161817 A1 describes a circuit for supplying electrical power to the coil of a relay. The current required for this can be provided by a battery. Two parallel feed lines are provided, each containing a field-effect transistor (FET) as a switch. To energize the coil, the gate voltages of the FETs are synchronously adjusted to values ​​that allow current to flow through both FETs. The gate voltages are slightly reduced at regular time intervals, and the voltage drop between the drain and source is measured. The measurements are evaluated in terms of wire breaks in the feed lines leading to the FETs. Disadvantageously, the barrier layer capacitance is not measured. Instead, the FET is only periodically controlled at a lower voltage. Additionally, the load voltage must also be measured. A measurement system with high fail-safety is not disclosed here.

[0008] EP 133 5471A2 and DE 382 1065 illustrate a protection wiring circuit implemented using a "monitor" transistor. If the voltage across the main transistor drops too high, the main transistor is turned off. The disadvantage is that the main transistor is only protected when the voltage drops too high; it is not protected if it becomes low-ohm due to a fault and can no longer be turned off.

[0009] In the stated circumstances, it is impossible to diagnose the turn-off capability of a digital output terminal in the ON state. Against this backdrop of the prior art, the purpose of this disclosure is to describe an apparatus and a method, respectively suited to at least partially overcome the disadvantages of the aforementioned prior art and to enrich the prior art. Summary of the Invention

[0010] This objective is achieved through the features of the independent patent claims. The parallel and dependent patent claims each contain alternative modifications to this disclosure.

[0011] Thus, this objective is achieved by a device for monitoring the turn-off capability of a power consumer connected to a first current path having a current supply mechanism. A first electrical regulating element is provided in the first current path, the current-carrying capacity of which can be changed by means of a first regulating signal. The operating state of the first regulating element is characterized by a first electrical parameter, which is a first capacitance on the first regulating element and, depending on the case, a first voltage obtained by a voltage measuring device. The device provides a second regulating element in a second current path having a separate current supply mechanism for providing a first regulating signal, the current-carrying capability of which can be changed by means of a second regulating signal. The operating state of the second regulating element is characterized by a second electrical parameter, which is a second capacitance on the second regulating element and, depending on the case, a second voltage. The first and second capacitances are connected in series. In addition, a control device is provided, which is designed to operate the second regulating element by means of a second regulating signal at least at measurement intervals that are time-spaced apart from each other, and to evaluate the value of the first electrical parameter obtained therein to identify a fault in the off-state of the first regulating element, wherein the evaluation includes comparing the value of the first electrical parameter obtained therein with at least one reference predetermined value.

[0012] In the sense of this disclosure, capacitance It can be understood as an electrical parameter that has the ability to store charge and build up capacitance. Capacitance can be built up by applying voltage.

[0013] In the context of this disclosure, turn-off capability can be understood as the ability of an adjustable element, such as a field-effect transistor (FET), to completely interrupt current flow between the source and drain when an appropriate control voltage is applied to the gate. Turn-off capability occurs when the voltage on the gate is adjusted such that the electric field in the channel is strong enough to completely block current flow. In this state, the FET is considered "off," and only a very small leakage current flows between the source and drain. The ratio between the leakage current in the off state and the maximum current in the on state can be called the turn-off ratio or turn-off current ratio.

[0014] In the sense of this disclosure, an electrical appliance can refer to a device or component in an electrical system that absorbs electrical energy and converts or utilizes it into another form of energy.

[0015] In the context of this disclosure, the current-carrying capacity of a field-effect transistor refers to the ability of the transistor to conduct current between the source and drain terminals when an appropriate control voltage is applied to the gate.

[0016] The aforementioned device offers a number of advantages. Furthermore, the disclosed device can detect when the voltage of the blocking layer capacitor falls below a predetermined threshold, thus preventing the regulating element (field-effect transistor) from turning off and consequently ensuring that the digital output and / or electrical load are switched to no voltage. Therefore, further protective measures can be implemented. It can be proposed to activate a second shutdown mechanism and switch the digital output and / or electrical load to no voltage. Additionally, in the case of a single switching element, it is possible to detect when shutdown is no longer guaranteed and output a fault report to prevent / prevent reconnection.

[0017] The following section will explain in detail the possible improvements to the above method.

[0018] It can be proposed that a capacitor be incorporated into the device. This capacitor can be coupled in parallel with a second regulating element to increase the capacitance of the second regulating element. The capacitance (especially the barrier layer capacitance) can be measured / observed using a capacitive voltage divider. For this purpose, an additional capacitor is connected in series with the capacitance to be measured (GS segment capacitance) of the first regulating element. The second regulating element can turn on the capacitor. In the switching state of the second regulating element, the capacitor is bridged. In the non-switching state (off state), the capacitor is switched, and the voltage drops. Alternatively, it can be proposed that the second regulating element has a drain-source capacitance whose specifications are determined in such a way that it fulfills the function of the capacitor. If the specifications of the drain-source capacitance are determined to be too small, and / or the second regulating element requires a larger structural type to achieve the corresponding capacitance, an additional capacitor can be connected in parallel with the second regulating element, which can have a correspondingly larger capacitance.

[0019] It can be proposed that the capacitance of the second capacitor, or the capacitance of the second capacitor connected in parallel with the first capacitor, has the same capacitance range as the first capacitor, wherein the capacitance range is in the range of at least 100pF to at most 10nF. Therefore, a corresponding voltage divider and a corresponding voltage drop can be implemented so that the first regulating element can still be switched, but the gate-source voltage is known simultaneously.

[0020] It can be proposed that the first regulating element and the second regulating element are transistors, and the regulating signal is a control current or a control voltage, wherein the transistor is an n-channel or p-channel field-effect transistor.

[0021] It can be proposed that the voltage measuring device be designed as an operational amplifier. The operational amplifier can compare the known gate-source voltage value with a reference value. The difference can be evaluated accordingly, and the result can be traced back to the turn-off characteristic or a fault occurring in the turn-off characteristic. Furthermore, the difference can be transmitted to a control device for processing.

[0022] It can be proposed that the voltage measuring device is designed as an analog-to-digital converter (ADC) and provides a digital signal to the control equipment based on the value of a relevant first electrical parameter. The ADC can convert the value of the relevant first electrical parameter, obtained as an analog voltage signal, into a digital signal. The converted digital signal can then be transmitted to the control equipment for further processing.

[0023] It can be proposed that the control device compares the value of the first electrical parameter with at least one first reference predetermined value and / or a second reference predetermined value, wherein one or more reference predetermined values ​​are provided by a resistive voltage divider. The reference predetermined value can be adjusted by the resistor to represent the limit of the voltage value at which the first regulating element can still be technically turned off. If the first regulating element can no longer be turned off due to, for example, complete melting, the obtained value of the first electrical parameter will be outside the range of values ​​provided by the resistive voltage divider.

[0024] It can be proposed that, in order to identify a fault where there is no off condition related to the first regulating element, the first electrical parameter is reduced by a coefficient from its maximum value, so that the first regulating element remains on or, if already off, remains off, and sufficient current flows through the consumer to perform its function. It can be found that the blocking layer capacitance is present when the applied voltage is reduced to a level sufficient to switch the first regulating element on. Therefore, the first regulating element is still determined to be turn-off. After sending a measurement pulse, the method for monitoring turn-off capability ends, and the device returns to its initial state, and the circuit operates in normal mode (e.g., for switching the consumer).

[0025] It can be proposed that a third regulating element be provided in the first current path, and the third regulating element be connected in series with the first switching element. If the blocking layer capacitance drops due to complete melting and the resulting voltage drop is also below a predetermined reference value, it is determined that the first regulating element can no longer be turned off, and the corresponding task in the device is no longer performed according to the standard. Thus, the digital output or electrical load can be turned off via an alternative shutdown route. This alternative shutdown route is provided by the third regulating element. Furthermore, fault reports can be provided by the control device through indicator lights, displays on the screen, and messages transmitted to other devices to warn the operator / user.

[0026] It can be proposed that, in order to identify a fault related to the shutdown of the first regulating element, the first electrical parameter is reduced as much as possible from its maximum value by a coefficient, and the first regulating element is no longer shut off, and a third regulating element is used to prevent sufficient current from consuming the device. Therefore, the device can be switched to a safe state, and the digital output or electrical load can be switched to no voltage, thereby preventing harm to third parties.

[0027] It can be proposed that the device also includes a resistive element, wherein the resistive element is connected in parallel with the first capacitance of the first regulating element. The device is designed such that the digital output is turned off when no second regulating signal is applied to the second regulating element. Therefore, the switching on energy is provided only for the duration of a short test pulse. For this purpose, a resistive element can be provided, the specifications of which can be determined such that any failure on the second regulating element will not cause the first regulating element to remain on for a predetermined process safety time.

[0028] The above can be summarized in other words and in conjunction with possible more specific design schemes of this disclosure as described below, wherein the following description should not be construed as a limitation of this disclosure.

[0029] The turn-off capability of a digital output terminal should be diagnosed by measuring the blocking layer capacitance of the field-effect transistor that is turned off when it is on.

[0030] Field-effect transistors (FETs) can be constructed by doping a substrate, thereby obtaining N-regions and P-regions. For example, the N-region of a self-stop N-channel FET can be contacted with the drain (D) and source (S). The FET can have an insulating layer in the P-region, preventing the gate (G) terminal from conducting. A barrier layer is located in this region. When a voltage is applied to the source (S) at the source (G), a capacitive charge is generated, which conducts through the barrier layer between the drain and source (D and S).

[0031] This structure results in a FET with a barrier layer capacitance that can be measured between the gate (G) and source (S). This capacitance can be measured even when the barrier layer is charged with a voltage.

[0032] A FET can have two main failure states between drain (D) and source (S): On the one hand, it may permanently become high-ohmic. Thus, it cannot be controlled to turn on by applying a voltage across gate (G) to source (S). If the turn-off state is a safe state, the FET fails in the safe direction. On the other hand, the FET may also permanently become low-ohmic. Here, the cutoff region is "completely melted." At this point, the FET can no longer be turned off. In the completely melted state, the FET no longer has the same barrier layer capacitance. Because the conductive portion of the cutoff region has the potential of the source (S) of the barrier layer capacitance, the barrier layer capacitance decreases. Therefore, the capacitance between gate (G) and source (S) is significantly reduced. The dielectric must have regions enriched with charge carriers and therefore must also have regions depleted of charge carriers. Complete melting occurs in the most direct connection between the doped regions, i.e., the enriched region. Therefore, the remaining barrier layer capacitance is considered to be less than 50% of the previous barrier layer capacitance.

[0033] Capacitance can be measured using a capacitive voltage divider. For this, an additional capacitor is connected in series with the capacitor under test. An additional FET can then be used to turn on this capacitor. The FET itself has drain-source capacitance, the specifications of which can be determined such that it is sufficient for this purpose on its own. Alternatively, an additional capacitor can be used.

[0034] The specifications of the barrier layer capacitor and series capacitor can be determined such that they are in the same order of magnitude, for example, between 100pF and 10nF. If another FET is switched to a high-ohm circuit, the charge of the barrier layer capacitor is shunt to a capacitive voltage divider. The magnitude of the shunt voltage should be determined such that the barrier layer capacitor has sufficient charge to continue controlling the FET's conduction. The shunt voltage can be found in terms of its appropriate range.

[0035] If the FET has completely melted, the voltage is outside the effective range. Therefore, it can be diagnosed that the FET can no longer be turned off. To measure the voltage across the capacitive voltage divider, an operational amplifier can be provided, which compares the voltage supplied through the resistive voltage divider with a reference voltage.

[0036] Alternatively, voltage can be detected using other measurement methods, such as analog-to-digital converters using microcontrollers.

[0037] The application scheme also includes an additional turn-off path, such as another FET connected in series with the aforementioned FET. If the test reveals that the FET can no longer be turned off, i.e., it has completely melted, then turn-off is triggered via a redundant turn-off path.

[0038] The application scheme also includes a control mechanism, such as a gate driver or a microcontroller, at the digital output of another FET at D. The diagnostic interconnect circuit is designed such that the output is turned off when no voltage is applied to D of the other FET. Therefore, the switching turn-on energy is provided only for the duration of a short test pulse.

[0039] To this end, a resistor can be provided, its specifications determined such that any failure of another FET will not cause the FET to remain on for a predetermined process safety time. The interconnect circuitry is designed such that any simple fault will not result in the loss of safety functionality, and the diagnostic coverage is very high. During testing, the FET is briefly not fully controlled to conduct. This causes an increase in voltage drop (DS segment) and thus heat generation. An advantageous design for the FET is to over-specificate its specifications, allowing it to withstand power higher than the power required to withstand the current measured when it is permanently fully controlled to conduct.

[0040] The switchability of the initial FET can be checked using the following method.

[0041] The initial state includes: the drain (D) of another FET is loaded with voltage, the gate (G) of another FET is loaded with voltage, the other FET is switched on (DS segment), the gate (G) of another FET is loaded with voltage, the drain (D) of another FET is supplied with voltage, and the FET is switched on (DS segment).

[0042] A test pulse is applied to the gate (G) of another FET to reduce the gate-gate voltage to zero and make the other FET high-ohm. The reverse capacitance of the capacitor and the other FET is measured. A capacitive voltage divider is formed with the charged barrier layer capacitance of the FET. Thus, the FET discharges according to the capacitance ratio and retains the resulting voltage on the FET's gate (G).

[0043] If the barrier layer capacitance is present normally, the voltage across the gate (G) of the FET can be measured. A reduced voltage is then applied, but this reduced voltage is still sufficient to turn the FET on. If the barrier layer capacitance is significantly reduced due to complete melting, the applied voltage is significantly reduced.

[0044] The following criteria can be used to assess whether the voltage is below a defined threshold. If the voltage drops only slightly, the FET can still be turned off.

[0045] The test pulse ends, and the system returns to the initial state.

[0046] If the voltage drops below a predetermined threshold, the FET cannot be turned off. The output is turned off via a second turn-off path. A fault report is output and re-enabling is prevented. If the FET's gate voltage U_G is detected both with and without a test pulse, the following faults can be identified:

[0047] (1) Complete melting of the FET (the DS section is low ohmic) causes the capacitance C_GS to decrease, and thus causes the voltage U_G to increase during the test pulse.

[0048] (2) Complete melting of the FET (when the DG or SG section is low ohms) causes the gate to turn off, thus resulting in a decrease (or increase) in voltage. Alternatively, complete melting of the FET or high ohms (DS section) causes a change in the capacitive voltage divider, thus resulting in a decrease or increase in voltage.

[0049] If a fault is detected, the system will shut down.

[0050] Alternatively, in the second variant, it can be proposed to measure the drain-source voltage change caused by capacitive discharge. This can be accomplished by: 1. using an interconnect circuit that measures only the alternating voltage component; or 2. using a bandpass filter if it is periodically switched on and off at a certain frequency. The voltage can also be detected and measured using an analog-to-digital converter.

[0051] Furthermore, a method is provided for monitoring the turn-off capability of a power consumption connected to a first current path having a current supply mechanism, wherein a first electrical regulating element is provided in the first current path, the current-carrying capacity of which can be changed by means of a first regulating signal, wherein the operating state of the first regulating element is characterized by a first electrical parameter, which is a first capacitance on the first regulating element and, depending on the case, a first voltage known from a voltage measuring device, wherein the device provides a second regulating element in a second current path having a separate current supply mechanism for providing the first regulating signal, the second regulating element... The current-carrying capacity of the regulating element can be changed by means of a second regulating signal, wherein the operating state of the second regulating element is characterized by a second electrical parameter, which is a second capacitance on the second regulating element and, depending on the case, a second voltage, wherein the first capacitance and the second capacitance are connected in series, and wherein the control device operates the second regulating element by means of the second regulating signal at least at measurement intervals that are time-separated from each other, and evaluates the value of the first electrical parameter obtained therein to identify faults in the shutdown condition of the first regulating element, and wherein the evaluation includes comparing the obtained value with a reference predetermined value.

[0052] Furthermore, a control device for operating a device according to the present disclosure is provided, the control device being designed to implement the method according to the present disclosure, the control device comprising: a processor unit configured to provide control signals to operate a second regulating element at least at measurement intervals spaced apart from each other in time; an interface configured to provide control signals and receive obtained values ​​of a first electrical parameter relating to a first regulating element; and wherein the processor unit is further configured to provide control signals to evaluate a fault identifying a shutdown condition relating to the first regulating element, and wherein the evaluation includes comparing the obtained values ​​of the first electrical parameter with at least one predetermined reference value.

[0053] Furthermore, a system having a first device and a second device according to the present disclosure is provided, wherein the first device and the second device are thus present in a particularly replicated manner and are arranged such that the negative terminal of the first (upper) device (100) is coupled to the positive terminal of the (lower) device (100).

[0054] Furthermore, this disclosure also relates to a computer program. The above-described method design can also be designed as a computer program, wherein, when implemented on a control device or a processor of the control device, it causes the control device (e.g., a computer, microcontroller, DSP, FPGA, and / or SPS) to execute the method according to this disclosure. The computer program can be provided as a signal by downloading or stored in a memory unit of the control device containing computer-readable program code, so as to cause the control device to execute instructions according to the above-described method. Here, the computer program can also be stored on a machine-readable storage medium.

[0055] Therefore, an alternative solution proposes a storage medium, particularly a computer-readable storage medium, which is configured to store the method according to this disclosure (as program code) and is readable by a computer or a computer's processor. When implemented by the processor circuitry of a computer or a computer network, the program code enables the implementation of an embodiment of the method according to this disclosure.

[0056] For example, the storage medium may be provided at least partially as non-volatile data memory (e.g., flash memory and / or SSD (Solid State Drive)) and / or at least partially as volatile data memory (e.g., RAM (Random Access Memory)). The storage medium may be arranged within its data memory in processor circuitry. However, the storage medium may also function, for example, as a so-called application store server on the Internet. Processor circuitry having at least one microprocessor may be provided via a computer or computer network. Program code may be provided as binary code or assembly language and / or as source code in a programming language (such as C) and / or as a program script (such as Python).

[0057] The aforementioned design schemes and improvements can be combined with each other arbitrarily where meaningful. Other possible design schemes, improvements, and implementations of this disclosure also include combinations of features not explicitly mentioned in the improvements described above or below in this disclosure. In particular, those skilled in the art will also add individual viewpoints as improvements or supplements to the corresponding basic form of this disclosure. Specifically, the features of the device claims can be implemented and / or carried out through corresponding functions, thereby supplementing or extending the method. Furthermore, method steps can be implemented through corresponding implementation modules in the device. Therefore, the above description of the device also applies similarly to the method, and vice versa. Attached Figure Description

[0058] Further details and advantages of this disclosure will now be explained in more detail based on the embodiments shown in the accompanying drawings.

[0059] In the attached diagram:

[0060] Figure 1 A schematic diagram of a device according to this disclosure is shown;

[0061] Figure 2 A schematic diagram of a system according to this disclosure is shown;

[0062] Figure 3 Further schematic diagrams of the device according to this disclosure are shown;

[0063] Figure 4 A flowchart of the method according to this disclosure is shown; and

[0064] Figure 5 A schematic diagram of a control device according to this disclosure is shown. Detailed Implementation

[0065] The accompanying drawings are intended to aid in a further understanding of improvements to the present disclosure. These drawings illustrate several improvements and, in conjunction with the specification, are used to elucidate the principles and concepts of the present disclosure. Given these drawings, various improvements are achieved, and many of the advantages already mentioned are noted. Elements in the drawings are not necessarily shown to scale.

[0066] In the accompanying drawings, identical, functional, and operational elements, features, and components (unless otherwise specified) will be given the same reference numerals.

[0067] Reference Figure 1 The first embodiment of this device has been explained. Figure 1 A schematic diagram of the device 100 according to the present disclosure is shown.

[0068] Device 100 (especially electronic equipment) is configured to monitor the turn-off capability of a power consumer 50 connected to a first current path having current supply mechanisms 1, 3. The power consumer 50 is coupled to device 100 via terminals 2, 4. Terminals 2, 4 represent outputs that can be switched by a first regulating element 10.

[0069] The first regulating element 10 is connected in the first current path and has an electrical connection mechanism to a voltage source. The first regulating element 10 can be designed as a field-effect transistor.

[0070] The current-carrying capacity of the first regulating element 10 can be changed by means of the first regulating signal 11. The first regulating signal 11 can be current or voltage.

[0071] The operating state of the first regulating element 10 can be characterized by a first electrical parameter, which is the first capacitance C on the first regulating element. GS10And, depending on the circumstances, the first voltage U is obtained from the voltage measuring device 30. GS10 .

[0072] Voltage measuring device 30 can obtain / measure the first voltage U on the gate-source section of the first regulating element 10. GS10 The voltage measuring device 30 can be designed as an operational amplifier that receives voltage at its input.

[0073] Other designs for the voltage measuring device 30 may be proposed, which know and / or provide information about the first voltage U on the gate-source section of the first regulating element 10. GS10 The value of the first regulating element 10 is coupled to the voltage supply mechanism 1 via a drain terminal. Furthermore, the first regulating element 10 is coupled to the consumer 50 via a source terminal.

[0074] The device 100 has a second regulating element 20 in the second current path. The second regulating element 20 can be designed as a field-effect transistor.

[0075] The second current path has an additional current supply mechanism 5. The second regulating element 20 is designed to provide a first regulating signal 11 for controlling the first regulating element 10. In particular, the first regulating signal 11 is provided in the switching state of the second regulating element 20.

[0076] The current-carrying capacity of the second regulating element 20 can be changed by the second regulating signal 21. The second regulating signal 21 can be provided by the control device 60. The operating state of the second regulating element 20 can be characterized by a second electrical parameter, which is the second capacitance C on the second regulating element 20. GS20 And depending on the situation, it is the second voltage (gate-source voltage) U. GS20 .

[0077] The proposed approach is to connect the first capacitor and the second capacitor in series.

[0078] Specifically, a capacitive voltage divider consisting of a first capacitor and a second capacitor is provided. Therefore, in this example, the drain-source capacitance and gate-source capacitance of the second regulating element 20 form a capacitive voltage divider.

[0079] In addition, a control device 60 is provided in the device 100. The control device 60 may be designed as a microcontroller, FPGA, computer, SPS or similar control device. In particular, the control device 60 may be designed as a device having an interface 62 configured to receive and provide signals / data.

[0080] In particular, the control device 60 is configured to operate the second adjustment element 20 by means of the second adjustment signal 21 at least according to a measurement interval that is time-separated from each other.

[0081] By providing a measurement pulse as the second adjustment signal 21, the second adjustment element 20 can be switched, or switched to high ohms in the absence of the control signal 21. When the second adjustment element 20 is switched to high ohms, the charge of the barrier layer capacitor of the first adjustment element 10 is shunted to the capacitive voltage divider.

[0082] The voltage can be queried and assessed by the first voltage measuring device 30 to determine whether it remains within the range pre-defined as fault-free shutdown. In the event that the first regulating element 10 is completely melted, the voltage will be outside the effective range. This allows diagnosis that the first regulating element 10 can no longer be shut off. Therefore, faults related to the shutdown condition of the first regulating element 10 can be identified by evaluating the obtained values ​​of the first electrical parameters.

[0083] The evaluation of the obtained values ​​of the first electrical parameter includes a comparison with at least one predetermined reference value.

[0084] One or more reference predetermined values ​​can be provided by resistive voltage dividers 52, 53, and 54. A voltage 5 is applied to resistive voltage dividers 52, 53, and 54. The resistance values ​​can be selected such that the provided reference predetermined values ​​can ensure the limit of the turn-off capability of the first regulating element 10.

[0085] The first voltage measuring device and the second voltage measuring devices 30 and 40 can receive reference predetermined values ​​from the resistive voltage dividers 52, 53, and 54. Furthermore, the first voltage measuring device 30 is coupled to the gate terminal of the first regulating element 10 to receive a first electrical parameter.

[0086] Measurements can be performed by comparing a first electrical parameter, including the gate-source voltage of the first regulating element 10 and the drain-source voltage of the second regulating element 20, with a predetermined reference value.

[0087] The two capacitive segments are compared by measuring the voltage drop. If the capacitance of the gate-source segment is less than that of the drain-source segment, the gate-source voltage is greater than the drain-source voltage, and the first regulating element 10 is allowed to maintain control conduction.

[0088] The equipment according to this disclosure can ensure safety in preventing the following two situations where complete melting would cause a failure in turnoff capability.

[0089] Complete melting of the first regulating element 10 may cause a decrease in the capacitance of the barrier layer, which in turn causes a voltage increase via the capacitive voltage divider. A maximum reference preset value can be set for the increased value.

[0090] Complete melting of the first regulating element 10 may cause the gate to shut down and the voltage to decrease. A maximum reference predetermined value can be set for the decrease.

[0091] Instead of an operational amplifier, an analog-to-digital converter can be used.

[0092] The analog-to-digital converter can convert the detected first electrical parameter into a digital signal and provide it to the user via interface 62. Figure 5 The control device 60 shown is shown.

[0093] The control device 60 particularly has a processor unit 61.

[0094] Processor unit 61 is designed to provide control signals to manipulate the second regulating element 20 at least according to measurement intervals spaced apart from each other in time. Interface 62 is designed to provide control signals and receive values ​​of first electrical parameters obtained regarding the first regulating element 10.

[0095] Furthermore, the processor unit 61 is also designed to provide control signals to evaluate faults that identify the shutdown status of the first regulating element 10, wherein the evaluation includes comparing the obtained value of the first electrical parameter with at least one reference predetermined value.

[0096] The control device 60 may have a memory unit 63 in which corresponding reference predetermined values ​​are stored.

[0097] The processor unit 61 of the control device 60 can compare the digital signal from the analog-to-digital converter with a stored reference predetermined value and issue a signal identifying a fault related to the shutdown state of the first regulating element 10. The control device 60 can provide a signal such that it is forwarded to another device for outputting a warning.

[0098] In addition, the control device 60 can also manipulate other devices to trigger warnings.

[0099] In one implementation, refer to Figure 1 It can be proposed that an additional capacitor 13 is connected in series with the capacitor to be measured (blocking layer capacitor) of the first adjustment element 10. This allows the drain-source capacitor, and consequently the second adjustment element 20, to be designed to be smaller.

[0100] The additional capacitor 13 can be switched by the second adjusting element 20. The capacitor 13 is selected such that a corresponding voltage is still applied to the first adjusting element 10 in the capacitive voltage divider, thereby causing the capacitive voltage divider to switch.

[0101] The specifications of the barrier layer capacitor (gate-source) of the first regulating element 10 and the other capacitor 13 can be determined such that they are in the same order of magnitude, for example, in the range of 100pF to 10nF.

[0102] If the second regulating element 20 is switched to high ohms, the charge of the barrier layer capacitor of the first regulating element 10 is shunted to a capacitive voltage divider consisting of another capacitor 13 (in place of the capacitor in the drain-source section of the second regulating element 20). The magnitude of the divided voltage should be determined such that the barrier layer capacitor is sufficiently charged to allow the first regulating element 10 to continue to be controlled and turned on.

[0103] The voltage can be queried in terms of its proper range.

[0104] If the first regulating element 10 is completely melted, the voltage is outside the effective range. Therefore, it can be determined that the first regulating element 10 can no longer be turned off.

[0105] Device 10 is designed such that the output is turned off when there is no voltage at the drain terminal of the second regulating element 20. Switching turn-on energy is provided during the duration of a short test pulse. For this purpose, a resistor 51 is provided, the specifications of which are determined such that any failure of the second regulating element 20 will not cause the first regulating element 10 to remain on for a predetermined process safety time.

[0106] An alternative design approach could involve measuring the drain-source voltage variation caused by capacitive discharge. This can be done, on one hand, by using an interconnect circuit that measures only the alternating voltage component; on the other hand, it can be achieved using a bandpass filter when periodically switched on and off at a certain frequency. The voltage could also be detected and measured using an analog-to-digital converter. In this regard, the barrier layer capacitance can be determined using different / alternative measurement principles.

[0107] It could be suggested that the capacitance be determined based on the discharge curve rather than using a capacitive voltage divider. If Figure 1 The capacitor C shown DS20 The capacitance of the barrier layer is very small compared to the capacitance to be measured (i.e., negligible as a preliminary approximation) and no capacitor 13 is provided, but the specifications of resistor 51 are determined to be suitable for this purpose. The barrier layer capacitance can then be determined by the discharge time. Here, a test pulse can be initiated, and the time required for the voltage to drop below the reference value can be measured.

[0108] In alternative / supplementary design schemes, according to Figure 3 The device 100 has a third adjustment element 70.

[0109] The third regulating element 70 is connected in series with the first regulating element 10 in the first current path. If the voltage is assessed to have dropped below a predetermined reference value, the first regulating element 10 cannot continue to be turned off.

[0110] Outputs 4, 2 and / or power consumption 50 will be shut down via a second shutdown circuit including a third regulating element 70. A fault report is output and reconnection is prevented. The third regulating element 70 can be controlled by a control device 60.

[0111] Reference Figure 2 An alternative design scheme for the equipment is explained here. It is based on the above reference. Figure 1 The first embodiment of the device explained; elements that are the same or have the same function are given the same reference numerals and will not be described in detail again. In particular, from Figure 2 From this, we can learn that the system 200 is based on the contents of this disclosure.

[0112] System 200 has a first device and a second device 100 according to this disclosure. The first device and the second device 100 exist in a duplicate manner and are arranged such that the negative terminal of the first (upper) device (100) is coupled to the positive terminal of the (lower) device 100. Furthermore, system 200 also has an output terminal 201 for intercepting the voltage on the negative terminal. The first device 100 and the second device are coupled to a power consumer 50.

[0113] In the design of system 200, a second shutdown channel is provided. Since there are two devices 100 for switching between positive and negative channels, a second shutdown channel is maintained outside the devices even in the event of a cross-connection. If the consumer 50 experiences an external power supply on the positive channel due to a fault, the second device 100 (acting as an M switch) still prevents current flow. If a ground fault occurs on the negative channel of the consumer 50, the first device 100 (acting as a P switch) can still prevent current flow.

[0114] Figure 4 A flowchart of a method according to this disclosure is shown. Figure 4 In the accompanying drawings, reference numeral V indicates an embodiment of the method according to this disclosure. The method V for monitoring turn-off capability has multiple method steps. Method V can be implemented by the processor unit 61 of the control device 60. In the first step S1, the second regulating element 20 is manipulated by means of a second regulating signal 21 at least according to measurement intervals spaced apart from each other in time. In the second step S2, the values ​​of the first electrical parameters obtained therein are evaluated to identify faults related to the turn-off condition of the first regulating element 10.

[0115] List of reference numerals

[0116] 1.3 Current supply mechanism

[0117] 10 First Adjustment Element

[0118] 11 First adjustment signal

[0119] 13 Capacitors

[0120] 20 Second Adjustment Element

[0121] 21 Second adjustment signal

[0122] 30 Voltage measuring device

[0123] 40 Voltage measuring device

[0124] 50 Consumables

[0125] 51 Resistor element

[0126] 52, 53, 54 Resistive Voltage Dividers

[0127] 60 Control equipment

[0128] 61 processor units

[0129] 62 interface

[0130] 63 memory units

[0131] 70 Third Adjustment Element

[0132] 71 Third adjustment signal

[0133] 100 devices

[0134] 200 system

[0135] 201 Voltage supply mechanism negative terminal

[0136] V Method

[0137] S1-S2 Method Steps

Claims

1. A device for monitoring the turn-off capability of an electrical load, wherein the electrical load is connected to a first current path having a current supply mechanism, the device comprising: In the first current path, there is a first electrical regulating element, wherein the current carrying capacity of the first electrical regulating element can be changed by means of a first regulating signal, wherein the operating state of the first electrical regulating element is characterized by a first electrical parameter, the first electrical parameter being a first capacitance at the first electrical regulating element and generating a first voltage, wherein the first capacitance is the gate-source capacitance of the first electrical regulating element. A second electrical regulating element in a second current path, the second current path having a second current supply mechanism, the second electrical regulating element being used to provide the first regulating signal, wherein the current carrying capacity of the second electrical regulating element can be changed by means of the second regulating signal, the operating state of the second electrical regulating element being characterized by a second electrical parameter, the second electrical parameter being a second capacitance at the second electrical regulating element and generating a second voltage, wherein the second capacitance is the drain-source capacitance of the second electrical regulating element, and wherein the first capacitance and the second capacitance are connected in series; A control device, designed to operate the second electrical regulating element by means of the second regulating signal at least at measurement intervals spaced apart in time, and to evaluate the value of the first electrical parameter obtained therein to identify a fault in the shutdown of the first electrical regulating element, wherein the evaluation of the value of the first electrical parameter includes comparing the value of the first electrical parameter with at least one predetermined reference value; and A resistive voltage divider, wherein the control device is designed to compare the value of the first electrical parameter with at least one first reference predetermined value and / or a second reference predetermined value, and the at least one first reference predetermined value and / or a second reference predetermined value is provided by the resistive voltage divider.

2. The device according to claim 1, wherein, The device also includes a capacitor, which is coupled in parallel with the second electrical regulating element to increase the overall capacitance of the second electrical regulating element.

3. The device according to claim 2, wherein, The capacitance of the second capacitor, or the capacitance of the second capacitor connected in parallel with the first capacitor, has the same capacitance level as the first capacitor.

4. The device according to claim 3, wherein, The capacitance level is in the range of at least 100 pF to at most 10 nF.

5. The device according to claim 1, wherein, Each of the first and second electrical adjustment elements is a transistor, and each of the first and second adjustment signals is a control current or a control voltage, wherein the transistor used for each of the first and second electrical adjustment elements is an n-channel or p-channel field-effect transistor.

6. The device according to claim 1, wherein, The first voltage is obtained by a voltage measuring device, which is an operational amplifier or an analog-to-digital converter, and is designed to provide a digital signal to the control device based on the obtained value of the first electrical parameter.

7. The device according to claim 1, wherein, In order to identify a fault in which the first electrical regulating element is not turned off, the device is designed to reduce the first electrical parameter from its maximum value by a coefficient, so that the first electrical regulating element is still not turned off and there is sufficient current to flow through the electrical load to perform the function of the electrical load.

8. The device according to claim 1 further includes a third electrical regulating element in the first current path, the third electrical regulating element being connected in series with the first electrical regulating element.

9. The device according to claim 8, wherein, In order to identify the fault of the first electrical regulating element being turned off, the first electrical parameter is reduced by a coefficient from its maximum value and the first electrical regulating element is no longer turned off, and the third electrical regulating element is used to prevent the current sufficient to perform the function of the electrical load.

10. The device according to claim 1, further comprising a resistive element, wherein, The resistive element is connected in parallel with the first capacitance of the first electrical regulating element.

11. A control device for monitoring the turn-off capability of an electrical load connected via a first current path having a current supply mechanism to an electrical load in the device according to claim 1, the control device comprising: A processor unit, the processor unit being designed to provide control signals to manipulate a second electrical regulating element at least at measurement intervals spaced apart from each other in time; as well as An interface designed to provide control signals and receive the value of a first electrical parameter of a first electrical regulating element; The processor unit is also designed to provide control signals to assess a failure in the shutdown of the first electrical regulating element, and The evaluation process includes comparing the obtained value of the first electrical parameter with at least one predetermined reference value.

12. A method for monitoring the turn-off capability of an electrical load connected to a first current path having a current supply mechanism, wherein a first electrical regulating element is provided in the first current path, the method comprising: The current-carrying capacity of the first electrical regulating element can be changed by means of a first regulating signal. The operating state of the first electrical regulating element is characterized by a first electrical parameter, which is the gate-source capacitance of the first electrical regulating element, and generates a first voltage. The first voltage is known by a voltage measuring device, and a second electrical regulating element for providing the first regulating signal is provided in a second current path having a separate current supply mechanism. The current-carrying capacity of the second electrical regulating element can be changed by means of the second regulating signal. The operating state of the second electrical regulating element is characterized by a second electrical parameter, which is the drain-source capacitance of the second electrical regulating element and generates the second voltage. The gate-source capacitance of the first electrical regulating element and the drain-source capacitance of the second electrical regulating element are connected in series. The second electrical regulating element is operated by a control device using the second regulating signal at least according to a measurement interval that is time-separated from each other, and The value of the first electrical parameter obtained herein is evaluated to identify a fault in the shutdown of the first electrical regulating element, wherein the evaluation of the value of the first electrical parameter includes comparing the obtained value of the first electrical parameter with a reference predetermined value, wherein the reference predetermined value is provided by a resistive voltage divider.

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