DEVICE FOR DETECTING AN ELECTRIC ARC IN AN ELECTRONIC ASSEMBLY USING A MODIFIED PIERCE OSCILLATOR

Abstract

The invention relates to a device for detecting an electric arc in an electronic assembly, having: a transmission unit for generating an output signal, and an evaluation unit for receiving the output signal, where the transmission unit and the evaluation unit are connected to one another, where the transmission unit comprises an oscillator unit that generates an output signal having a frequency and/or an amplitude, and where the evaluation unit is configured to detect deviations, caused by an arc, in the output signal from the transmission unit. There is in particular a provision to implement the oscillator unit by way of a modified Pierce oscillator having an inverter, where the quartz is replaced by a detector coil. The invention furthermore relates to an electronic assembly of a motor vehicle having an apparatus to be controlled, in particular having a heating apparatus and having said device, and to a method for detecting an electric arc in an electronic assembly.

Claims

1. A device for detecting an electric arc in an electronic assembly, comprising: a transmission unit configured to generate an output signal, and an evaluation unit configured to receive the output signal, wherein the transmission unit and the evaluation unit are connected to one another, wherein the transmission unit comprises an oscillator unit, which is configured to generate an output signal having at least one of: a frequency and an amplitude, and wherein the evaluation unit is configured to detect deviations, caused by an arc, in the output signal of the transmission unit.

2. The device as claimed in claim 1, wherein the evaluation unit is further configured to transfer at least one of: the transmission unit and an apparatus to be controlled, to a safe state, wherein the evaluation unit is configured to detect an arc, which leads to a change in at least one of: the frequency and the amplitude of the output signal, within or outside the at least one of: the transmission unit and the apparatus to be controlled and to trigger a safe switch-off of at least one of: the transmission unit and the apparatus to be controlled, wherein the evaluation unit is configured to generate a control signal for switching off at least one of: the transmission unit and the apparatus to be controlled, wherein the control signal is configured to be received by at least one of: the transmission unit and a switching element for switching off at least one of: the transmission unit and the apparatus to be controlled.

3. The device as claimed in claim 2, wherein the device comprises a switching element for switching off at least one of: the transmission unit and the apparatus to be controlled, wherein the switching element is arranged at least one of: within and outside the at least one of: the transmission unit and the apparatus to be controlled, wherein the switching element is configured to switch off at least one of: the transmission unit and the apparatus to be controlled after receiving a control signal from the evaluation unit, wherein the switching element is designed to at least one of: establish and to interrupt the power supply to at least one of: the transmission unit and the apparatus to be controlled.

4. The device as claimed in claim 3, wherein the evaluation unit is configured to compare the output signal of the transmission unit after reception with an output signal that is stored in the evaluation unit, wherein a negative comparison indicates an arc in at least one of: the transmission unit and the apparatus to be controlled, wherein, for such a case, the device is preferably to transfer at least one of: the transmission unit and the apparatus to be controlled to a safe state, wherein, for such a case, the evaluation unit is configured to generate a control signal for safely switching off at least one of: the transmission unit and the apparatus to be controlled, wherein the evaluation unit comprises a memory for at least one of: the stored output signal and/or a comparator for comparing the stored output signal with the received output signal of the transmission unit.

5. The device as claimed in claim 4, wherein the evaluation unit is configured to measure at least one of: a frequency and an amplitude of the output signal and, in the event of a deviation in at least one of: the frequency and the amplitude of the transmission unit, caused by an arc that has occurred at least partially within at least one of: the transmission unit and the apparatus to be controlled, to generate a control signal for safely switching off at least one of: the transmission unit and the apparatus to be controlled, wherein the evaluation unit is configured to transmit the control signal for safely switching off at least one of: the transmission unit and the apparatus to be controlled to at least one of: the transmission unit and a switching element for switching off at least one of: the transmission unit and the apparatus to be controlled.

6. The device as claimed in claim 5, wherein the transmission unit, in particular the oscillator unit generates the output signal having at least one of: a frequency and an amplitude, wherein the output signal is designed as a voltage having at least one of: a frequency and an amplitude, wherein the oscillator unit is designed as an LC oscillator, wherein the frequency-determining inductance of the transmission unit, in particular of the oscillator unit, is preferably constructed as a detector coil, wherein at least one of: the inductance and the detector coil is designed as at least one of: a PCB coil and in a spiral shape.

7. An electronic assembly of a motor vehicle having an apparatus to be controlled, and having a device for detecting an electric arc, wherein the device comprises: a transmission unit configured to generate an output signal, and an evaluation unit configured to receive the output signal, wherein the transmission unit and the evaluation unit are connected to one another, wherein the transmission unit comprises an oscillator unit, which is configured to generate an output signal having at least one of: a frequency and an amplitude, and wherein the evaluation unit is configured to detect deviations, caused by an arc, in the output signal of the transmission unit.

8. The electronic assembly as claimed in claim 7, wherein at least one of: the assembly and the device is configured such that the transmission unit of at least one of: the device and the apparatus to be controlled of the assembly may be transferred to a safe state, wherein, a switching element of the device transfers at least one of: the transmission unit and the apparatus to be controlled to a safe state.

9. A method for detecting an electric arc in an electronic assembly comprising the following steps: transmitting an output signal from a transmission unit to an evaluation unit, receiving the output signal in the evaluation unit; comparing the received output signal with a stored output signal, in the event of a negative comparison, in which the received output signal does not correspond to the stored output signal, transmitting a control signal from the evaluation unit to at least one of: the transmission unit and a switching element for switching off at least one of: the transmission unit and the apparatus to be controlled of an electronic assembly.

10. The method as claimed in claim 9, wherein the method uses the device comprising: a transmission unit configured to generate an output signal, and an evaluation unit configured to receive the output signal, wherein the transmission unit and the evaluation unit are connected to one another, wherein the transmission unit comprises an oscillator unit, which is configured to generate an output signal having at least one of: a frequency and an amplitude, and wherein the evaluation unit is configured to detect deviations, caused by an arc, in the output signal of the transmission unit.

11. The device as claimed in claim 1, wherein the apparatus to be controlled is a heating apparatus.

12. The device as claimed in claim 11, wherein the heating apparatus is at least one of: an air heater and a water heater.

13. The electronic assembly as claimed in claim 7, wherein the apparatus to be controlled is a heating apparatus.

Description

[0070] The invention is explained in more detail below using an exemplary embodiment in conjunction with associated drawings, in which schematically:

[0071] FIG. 1 shows a schematic view of a device according to the invention for detecting an electric arc;

[0072] FIG. 2 shows a schematic view of an oscillator unit from FIG. 1; and

[0073] FIG. 3 shows a schematic view of a coil of the oscillator unit from FIG. 3.

[0074] In the following description, the same reference symbols are used for the same subjects.

[0075] FIG. 1 shows a schematic view of a device 1 according to the invention for detecting an electric arc.

[0076] FIG. 1 shows in more detail a device 1 having a transmission unit 2 for generating an output signal A and an evaluation unit 3 for receiving the output signal A, wherein the transmission unit 2 and the evaluation unit 3 are connected to one another.

[0077] The evaluation unit 3 is also preferably used to evaluate the output signal A and preferably to take into account and/or implement information contained therein.

[0078] In the present example, the transmission unit 2 and the evaluation unit 3 are connected to one another by cable. A radio connection is also conceivable.

[0079] As FIG. 1 also shows, the transmission unit 2 has an oscillator unit 4, which generates the output signal A having a frequency and an amplitude.

[0080] In this case, the evaluation unit 3 is configured to detect deviations, caused by an arc, in the output signal A of the transmission unit 2.

[0081] Illustrated more precisely, the evaluation unit 3 is configured to detect an arc, which leads to a change in the frequency and/or amplitude of the output signal A, within or outside the transmission unit 2 and to bring about a safe switch-off of the transmission unit 2 by virtue of the transmission unit 2 being transferred to a safe state. The transmission unit 2 can thus be transferred to a de-energized state.

[0082] Furthermore, the evaluation unit 3 is configured to generate a control signal S for switching off the transmission unit 2, which control signal can be received by a switching element 5 for switching off the transmission unit 2.

[0083] As shown by the arrangement of the switching element 5 in FIG. 1, the switching element 5 can be effected within or outside the transmission unit 2.

[0084] As already mentioned, the switching element 5 is configured to switch off the transmission unit 2 after receiving a control signal S from the evaluation unit 3. The transmission unit 2 can thus be transferred to a de-energized state.

[0085] In other words, the switching element 5 is able to guarantee or to establish or interrupt the power supply to the transmission unit 2.

[0086] In order that the evaluation unit 3 can detect different output signals A in terms of frequency and/or amplitude, the evaluation unit 3 is configured to compare the output signal A of the transmission unit 2 after reception with an output signal that is stored in the evaluation unit 3.

[0087] Here, a negative comparison indicates an arc in the transmission unit 2, wherein, for such a case, the device 1—as already described—is configured to transfer the transmission unit 2 to a safe state by virtue of a control signal S for safely switching off the transmission unit 2 being generated.

[0088] Of course, the evaluation unit 3 has a memory for the stored output signal and a comparator for comparing the stored output signal with the received output signal A of the transmission unit 2.

[0089] Described again in other words, the evaluation unit 3 is configured to measure a frequency and/or an amplitude of the output signal A and, in the event of a deviation in the frequency and/or the amplitude of the transmission unit 2, caused by an arc that has occurred at least partially within the transmission unit 2, to generate a control signal S for safely switching off the transmission unit 2.

[0090] In this case, the evaluation unit 3 is configured to transmit the control signal S for safely switching off the transmission unit 2 to the switching element 5 for switching off the transmission unit 2.

[0091] FIG. 2 shows a schematic view of the oscillator unit 4 from FIG. 1, wherein FIG. 3 illustrates a schematic view of a coil of the oscillator unit 4 from FIG. 3.

[0092] As already mentioned several times, the transmission unit 2 or the oscillator unit 4 generates the output signal A having a frequency and/or an amplitude, wherein the output signal A is designed as a voltage or as a voltage signal.

[0093] In this case, according to FIG. 2, the oscillator unit 4 is constructed in the form of a Pierce circuit, wherein the quartz oscillator normally used in the Pierce circuit is replaced by a coil L.

[0094] With regard to a configuration of the oscillator unit 4 in the form of a Pierce circuit, the so-called Schmitt trigger, which is used as an amplifier stage, is also omitted.

[0095] As FIG. 2 shows, the oscillator unit 4 in the form of a Pierce circuit has a resistor R1, which ensures the linear operation of an inverter I (for example component 74HC04).

[0096] A resistor R2 limits the peak current. The coil L or the inductance L is located in the feedback branch.

[0097] The two capacitors C1, C2 are used for phase shifting in order to reliably meet the phase condition of 180°.

[0098] As shown in FIG. 2, the oscillator unit 4 is designed—in other words—as an LC oscillator, wherein the frequency-determining inductance L of the oscillator unit 4 is constructed as a detector coil.

[0099] In the present case, the inductance L or the detector coil is designed as a PCB coil and in a spiral shape, wherein the inductance L is the size of one square centimeter (see FIG. 3).

[0100] For the sake of completeness, it should be mentioned that the described device 1 for detecting an electric arc can be arranged in an electronic assembly 10 of a motor vehicle.

[0101] According to FIG. 1, the electronic assembly 10 of a motor vehicle comprises, in addition to the device 1, an apparatus 11 to be controlled, in particular a heating apparatus 11.

[0102] The assembly 10 is configured here in such a way that the apparatus 11 to be controlled or the heating apparatus 11 of the assembly 10 can be transferred to a safe state, wherein the switching element 5 of the device 1 transfers the apparatus 11 to be controlled to a safe state.

[0103] Illustrated more precisely, the evaluation unit 3 is configured to detect an arc, which leads to a change in the frequency and/or amplitude of the output signal A, within or outside the heating apparatus 11 and to bring about a safe switch-off of the apparatus 11 to be controlled, which can be configured as a heating apparatus, in particular as an air and/or water heater, by virtue of the heating apparatus 11 to be controlled being transferred to a safe state.

[0104] In this context, it should also be mentioned that the evaluation unit 3 can detect different output signals A with regard to frequency and/or amplitude. In this case, the evaluation unit 3 is configured to compare the output signal A of the transmission unit 2 after reception with an output signal that is stored in the evaluation unit 3.

[0105] A negative comparison indicates an arc in the transmission unit 2 and/or the heating apparatus 11 to be controlled, wherein, for such a case, the device 1 or the electronic assembly 10—as already described—is configured to transfer the heating apparatus 11 to a safe state by means of the switching element 5.

[0106] In this case, the assembly can include a system voltage in the high-voltage range, of over 12 volts, in particular of 42 or 48 volts or up to 800 V.

[0107] Finally, a method for detecting an electric arc in an electronic assembly is briefly described.

[0108] This method uses the device 1 presented and comprises the steps of: [0109] a) transmitting an output signal A from a transmission unit 2 to an evaluation unit 3, [0110] b) receiving the output signal A in the evaluation unit 3, [0111] c) comparing the received output signal A with a stored output signal, [0112] d) in the event of a negative comparison, in which the received output signal A does not correspond to the stored output signal, transmitting a control signal S from the evaluation unit 3 to a switching element 5 for switching off the transmission unit 2 and/or the apparatus 11 to be controlled of the electronic assembly 10.

LIST OF REFERENCE SIGNS

[0113] 1 Device for detecting an electric arc [0114] 2 Transmission unit [0115] 3 Evaluation unit [0116] 4 Oscillator unit [0117] 5 Switching element [0118] 10 Assembly [0119] 11 Heating apparatus [0120] A Output signal [0121] S Control signal [0122] L Inductance/coil [0123] R1 Resistor [0124] R2 Resistor [0125] C1 Capacitance/capacitor [0126] C2 Capacitance/capacitor [0127] I Inverter