Electronic security device

Abstract

The present invention relates to an electronic safety device (100) comprising: a semiconductor switch (1a, 1b, 1c), a load current detection device (2a, 2b, 2c) configured to detect a load current flowing through the semiconductor switch (1a, 1b, 1c) and to provide a corresponding load current signal (ISa, ISb, ISc), and a load current monitoring unit (4) to which the load current signal (ISa, ISb, ISc) is provided and which is configured to evaluate the load current signal (ISa, ISb, ISc) by means of an evaluation procedure (4.1), wherein the load current monitoring unit (4) is configured to execute the evaluation procedure (4.1) only if at least one test parameter exceeds an associated threshold value.

Description

[0001] The present invention relates to an electronic safety device comprising: a semiconductor switch, a load current detection device configured to detect a load current flowing through the semiconductor switch and to provide a corresponding load current signal, and a load current monitoring unit to which the load current signal is provided and which is configured to evaluate the load current signal by means of an evaluation procedure.

[0002] Such an electronic security device is known, for example, from US 11,611,205 B2.

[0003] The present invention is based on the objective of realizing a resource-saving electronic security device.

[0004] This problem is solved according to the invention by an electronic security device with the features of claim 1.

[0005] The electronic safety device according to the invention comprises at least one semiconductor switch designed to be connected on the input side to an electrical power source, in particular a vehicle battery and / or a vehicle DC-DC converter, and on the output side to an electrical load to be protected. The semiconductor switch is preferably a so-called power semiconductor switch. Preferably, the semiconductor switch comprises at least one, preferably several, so-called MOSFETs (metal-oxide-semiconductor field-effect transistors) connected in parallel. However, it is also conceivable that the semiconductor switch comprises one or more so-called IGBTs (bipolar transistors with insulated gates), one or more JFETs (junction field-effect transistors), one or more BJTs (bipolar transistors), or one or more HEMTs (high electron mobility transistors).

[0006] The electronic safety device further comprises a load current sensing device, which is configured in a known manner to detect a load current flowing through the semiconductor switch, specifically through a so-called load current path of the semiconductor switch, and to provide a corresponding load current signal. The load current sensing device can, for example, include a measuring resistor and a differential amplifier connected to the input and output of the measuring resistor. Preferably, the load current sensing device is configured to output an analog load current signal. However, it is also conceivable that the load current sensing device includes an analog-to-digital converter for generating a digital load current signal.

[0007] The electronic safety device further comprises a load current monitoring unit, to which the load current signal is supplied and which is configured to evaluate the load current signal by means of an evaluation procedure. The load current monitoring unit includes a computer system in which the evaluation procedure is stored as a computer program. The evaluation procedure is designed in a known manner to determine, by evaluating the load current signal, whether or not specified conditions for tripping the electronic safety device are present, i.e., for interrupting the power supply by appropriately controlling the semiconductor switch.

[0008] Since executing the evaluation procedure is relatively computationally intensive and memory-intensive, the load current monitoring unit according to the invention is configured to compare at least one test parameter with an associated threshold value and to execute the evaluation procedure only if at least one test parameter exceeds the associated threshold value. It is conceivable, in principle, that one or more test parameters are determined by the load current monitoring unit, for example, based on the load current signal or another provided measurement signal, or that one or more test parameters are provided to the load current monitoring unit, for example, by a higher-level control unit.

[0009] The load current monitoring unit set up according to the invention therefore avoids unnecessary execution of the evaluation procedure, thus enabling the realization of a resource-saving electronic safety device.

[0010] In principle, the load current monitoring unit can comprise any type of computer system. However, in a preferred embodiment, the load current monitoring unit includes a microcontroller, or is formed by a microcontroller. Microcontrollers are inexpensive, standard components that can be programmed easily and in a variety of ways. Furthermore, microcontrollers typically include at least one analog-to-digital converter and are therefore suitable for receiving and processing an analog load current signal or other analog measurement signals.

[0011] Preferably, the load current monitoring unit is configured to determine a test parameter based on the load current signal. Preferably, the test parameter determined based on the load current signal indicates or estimates the current load current flowing through the semiconductor switch. The test parameter can, for example, indicate the current amplitude or magnitude of the load current signal. However, it is also conceivable that the test parameter indicates a rate of change or another parameter that indicates or estimates the extent of a change in the load current signal.

[0012] In a preferred embodiment, a temperature signal is additionally provided to the load current monitoring unit, and the load current monitoring unit is configured to determine a test parameter based on the temperature signal. The temperature signal can be an analog signal or a digital signal, with a digital temperature signal preferably providing the test parameter directly to the load current monitoring unit. The temperature signal can be provided to the load current monitoring unit directly by a temperature sensing device, or it can be provided to the load current monitoring unit by a data processing unit or control unit. The temperature signal can, for example, indicate or estimate the temperature of an electrical load to be protected by the electronic safety device.However, the temperature signal can also indicate or estimate the temperature of a component of the electronic safety device itself, for example the semiconductor switch.

[0013] In a further preferred embodiment, a voltage signal is additionally provided to the load current monitoring unit, and the load current monitoring unit is configured to determine a test parameter based on the voltage signal. The voltage signal can be an analog signal or a digital signal, with a digital voltage signal preferably providing the test parameter directly to the load current monitoring unit. The voltage signal can be provided to the load current monitoring unit directly by a voltage sensing device, or it can be provided to the load current monitoring unit by a data processing unit or control unit. The voltage signal can, for example, indicate or estimate the electrical voltage across an electrical load to be protected by the electronic safety device.The voltage signal can also indicate or estimate the electrical voltage at a component of the electronic safety device itself, for example, at a terminal of the semiconductor switch. The test parameter determined based on the voltage signal can, for example, specify the current amplitude or magnitude of the voltage signal. However, it is also conceivable that the test parameter determined based on the voltage signal indicates a rate of change or another parameter that specifies or estimates the extent of a change in the voltage signal.

[0014] In a further preferred embodiment, the load current monitoring unit is additionally provided with a trigger signal and is configured to determine a test parameter based on this trigger signal. Preferably, the trigger signal is designed to transmit trigger information that can have only two states: a trigger state or a non-trigger state. The trigger state signals that the evaluation procedure should be initiated, and the non-trigger state signals that the evaluation procedure should not be initiated. Consequently, the trigger state corresponds to a test parameter determined based on the trigger signal that is greater than the associated threshold, and the non-trigger state corresponds to a test parameter determined based on the trigger signal that is less than the associated threshold.The test parameter determined based on the trigger signal preferably indicates directly whether or not the evaluation procedure should be initiated. The trigger signal can be provided, for example, by a higher-level data processing unit or control unit. The trigger signal can be an analog signal, which can, for example, assume a high and a low voltage level, or it can be a digital signal that preferably provides the test parameter directly to the load current monitoring unit.

[0015] An embodiment of the present invention is described below with reference to the attached Fig. 1 described, which shows a schematic diagram of an electronic safety device according to the invention.

[0016] Fig.Figure 1 shows an electronic safety device 100 according to the invention, which in the present embodiment comprises three semiconductor switches 1a, 1b, 1c and is thus designed in the present embodiment to protect three electrical loads 101a, 101b, 101c, wherein the electronic safety device 100 could in principle also have any other number of semiconductor switches to protect a corresponding number of electrical loads.

[0017] All three semiconductor switches 1a, 1b, 1c are each electrically connected on the input side to an electrical energy source 102.

[0018] The first semiconductor switch 1a is electrically connected to the first load 101a on the output side, the second semiconductor switch 1b is electrically connected to the second load 101b on the output side, and the third semiconductor switch 1c is electrically connected to the third load 101c on the output side.

[0019] Each load 101a, 101b, 101c has a detection device 103a, 103b, 103c arranged which is configured to detect an electrical voltage and temperature applied to the respective load 101a, 101b, 101c and to provide a corresponding voltage signal USa, USb, USc and a corresponding temperature signal TSa, TSb, TSc.

[0020] The electronic safety device 100 comprises three load current detection devices 2a, 2b, 2c, each of which is configured to detect a load current flowing through the respective semiconductor switch 1a, 1b, 1c during operation and to provide a corresponding load current signal ISa, ISb, ISc.

[0021] The electronic safety device 100 comprises an input voltage detection device 3, which is configured to detect an input voltage applied to the inputs of the three semiconductor switches 1a, 1b, 1c and to provide a corresponding voltage signal USe.

[0022] The electronic safety device 100 comprises a current monitoring unit 4, which in the present embodiment is formed by a microcontroller 5.

[0023] The current monitoring unit 4 is provided with the load current signals ISa, ISb, ISc of all load current detection devices 2a, 2b, 2c, the voltage signals USa, USb, USc as well as the temperature signals TSa, TSb, TSc of all detection devices 103a, 103b, 103c, and the voltage signal USe of the input voltage detection device 3.

[0024] The current monitoring unit 4 is also provided with a trigger signal AS from one of the control units 104 that is superior to the electronic safety device 100.

[0025] The current monitoring unit 4 is configured to determine a test parameter based on the load current signals ISa, ISb, ISc, the voltage signals USa, USb, USc, USe, the temperature signals TSa, TSb, TSc, and the trigger signal AS, and to compare the determined test parameters with an individual associated threshold value programmed into the microcontroller 5 in the present embodiment.

[0026] The current monitoring unit 4 is further equipped to evaluate the load current signals ISa, ISb, ISc by means of an evaluation procedure 4.1 programmed into the microcontroller 5 in the present embodiment in order to determine whether the respective semiconductor switch 1a, 1b, 1c should be controlled to interrupt the power supply to the respective load 101a, 101b, 101c.

[0027] The current monitoring unit 4 is configured to execute the evaluation procedure 4.1 only if one of the test parameters determined by the current monitoring unit 4 exceeds the respective threshold value. Reference symbol list 100 electronic safety devices 1a, 1b, 1c Semiconductor switches 2a, 2b, 2c load current detection devices 3 Input voltage detection device 4 Power monitoring unit 4.1 Evaluation procedure 5 microcontrollers 101a, 101b, 101c Loads 102 Energy source 103a, 103b, 103c Recording devices 104 Control unit AS trigger signal ISa, ISb, ISc load current signals TSa, TSb, TSc temperature signals USa, USb, USc, USe voltage signals QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 11,611,205 B2

[0002]

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