WO2020127894A1

WO2020127894A1 - Circuit assembly for converting a differential input signal into a square output signal

Info

Publication number: WO2020127894A1
Application number: PCT/EP2019/086558
Authority: WO
Inventors: Wolfgang Fischer; Tobias Kirchner; Jonathan Mueller
Original assignee: Robert Bosch Gmbh
Priority date: 2018-12-21
Filing date: 2019-12-20
Publication date: 2020-06-25
Also published as: DE102018222835A1

Abstract

The invention relates to a circuit assembly (100) for converting a differential input signal into a square output signal comprising a first input terminal (In+) and a second input terminal (In-) for feeding the differential input signal into an input signal path, a first voltage terminal (V+) and a second voltage terminal (V-) for connecting to a supply voltage, an output terminal (Out) for outputting the square output signal, a signal evaluation unit (150) having a first input, a second input and an output, which unit is configured to represent at the output thereof whether an input signal between the first input and the second input has a positive or negative voltage difference, the first input of the signal evaluation unit (150) being connected to the first input terminal (In+) and the second input of the signal evaluation unit (150) being connected to the second input terminal (In-) via the input signal path, and the output of the signal evaluation unit (150) being connected to the output terminal (Out).

Description

description

title

Circuit arrangement for converting a differential input signal into a rectangular output signal

The present invention relates to a circuit arrangement for converting a differential input signal into a rectangular output signal.

State of the art

The angular position and the speed of the crankshaft one

Internal combustion engines are essential input variables for many functions of the electronic engine control. To determine them, a body rotating with the crankshaft of the internal combustion engine can be used in the same

Markings can be provided at angular distances. The passing of a mark as a result of the crankshaft rotation can be detected by a sensor and passed on to an electronic evaluation system as an electrical signal.

This electronics determines the respective stored signal for the marking or measures one for the respective angular position of the crankshaft

Time difference between two markings and, based on the known angular distance between two markings, can determine the angular velocity and the speed from this. In motor vehicles, especially ATV (All Terrain Vehicle), motorcycles, mopeds or motorcycles, the

Markings are provided, for example, by teeth of a metallic gear wheel, a so-called sensor wheel, which cause a change in the magnetic field due to their movement in the sensor. A gap of a few teeth can serve as a reference mark for the detection of the absolute position. While 60-2 teeth are mostly used in cars (even distribution of 60 teeth, two being left out), encoder wheels with 36-2, 24-2 or 12-3 teeth are also used for motorcycles or motorcycles. With this indirect principle of

Determining the rotational speed or determining the angular position of the crankshaft, the resolution of the rotational speed signal or the absolute detection of the angular position is determined by the number of teeth and by reliable detection of the reference mark.

In every modern vehicle with an internal combustion engine, a generator is installed, which is driven by the rotation of the crankshaft and supplies electrical signals which serve to supply the vehicle with electrical energy and to charge the vehicle battery. The intended operation of a vehicle without this generator is not possible or only possible for a short time.

A use of the electrical output variables of an electrical machine (generator) driven via the crankshaft is used, for example, in DE 10 2014 206 173 A1 for determining the speed. For this purpose, one or more signals of the electrical machine are evaluated, each of which has one or more values, each of which occurs at least once per revolution of the rotor of the electrical machine. The speed is calculated by calculating a time difference between two occurrences of values.

Furthermore, DE 10 2016 221 459 A1 discloses the use of such electrical output variables for determining an angular position of a crankshaft of an internal combustion engine. For this purpose, a

Occurrence of at least one value of a phase signal of the electrical machine, which occurs at least once per revolution of the rotor, used to determine an angular position of the rotor. The

The angular position of the crankshaft is calculated from the angular position and an angular offset.

Disclosure of the invention Against this background, a circuit arrangement for converting a differential input signal into a rectangular output signal with the features of claim 1 is proposed. Advantageous embodiments are the subject of the subclaims and the following description.

The circuit arrangement has a first input connection and a second input connection for feeding the differential input signal into an input signal path, a first potential connection and a second potential connection for connection to a supply voltage, and an output connection for outputting the rectangular output signal. For example, a source can be connected to the input connections that generates the differential input signal, for example a generator or a corresponding electrical machine. A differential input signal is understood to be a signal consisting of two antiphase signal parts, each of which is present at one of the inputs. In the case of a generator, a differential signal is present in particular at both ends of a stator phase winding.

A computing unit, for example, can be connected to the output connection

be connected, for example a control unit, for further, in particular digital evaluation of the output signal. In particular, a DC voltage source, e.g. a battery, are connected to supply the circuit arrangement or its components with electrical energy.

Furthermore, the circuit arrangement has a signal evaluation unit with a first input, a second input and an output, which is designed to show at its output whether an input signal has a positive or negative potential difference between the first input and the second input. In particular, this can be done by means of a positive and negative output signal level, in particular zero crossings of the input signal being output at the output as signal edges. Such a signal evaluation unit can in particular be a Amplifier circuit with a first input (in particular non-inverting input), a second input (in particular inverting input) and an output. The inputs and outputs of the amplifier circuit are each connected in a signal path to the corresponding inputs and outputs of the signal evaluation unit. The amplifier circuit can in particular have an operational amplifier, a comparator, a differential amplifier or also corresponding discrete circuits with comparable functionality.

Furthermore, the first input is via the input signal path

Signal evaluation unit connected to the first input connection, the second input of the signal evaluation unit to the second

Input connection and the output of the signal evaluation unit via an output signal path with the output connection. Thus the

The signal evaluation unit expediently supplies the differential input signal and converts it into the rectangular output signal, which is forwarded or made available to the output connection.

The circuit arrangement is set up to convert a differential, analog input signal, in particular a symmetrical, periodic signal, into a rectangular, digital output signal, in particular with two discrete levels. The circuit arrangement represents the zero crossings of the input signal as edges of the output signal, in particular as rising or falling edges in the output signal. The current level of the output signal expediently indicates whether there is currently a positive or a negative potential difference between the input connections. In particular, based on the first input connection, a positive input signal or a positive input voltage (ie potential at the first input connection higher than at the second) can be output as a high level and a negative sign of the input signal or a negative input voltage correspondingly as a low -Level. The output is switched in particular when the sign of the difference in the inputs changes, that is to say there is a zero crossing in the differential input signal. In particular, an electrical signal from a generator or a corresponding electrical machine can be used as the input signal, in particular a voltage or current signal from such an electrical machine, advantageously a phase voltage or a phase current of a phase of the electrical machine. Thus, through the

Circuit arrangement an analog electrical signal of the electrical

Machine are digitized, for example for evaluating or monitoring the electrical machine or components connected to it.

A phase of an electrical machine or its two ends is therefore advantageously connected to the first input connection and the second input connection.

The circuit arrangement is particularly suitable for use in a vehicle, in particular for an electrical machine coupled to a crankshaft of an internal combustion engine of the vehicle, which is e.g. as

Alternator can be formed. Electrical signals of the electrical machine, in particular phase currents or phase voltages, have zero crossings, which occur at least once per revolution of the rotor and thus per revolution of the coupled internal combustion engine. An evaluation of these zero crossings, in particular the time intervals between these zero crossings, expediently enables conclusions to be drawn about the speed of the internal combustion engine.

The circuit arrangement can thus advantageously be supplied with a phase current or a phase voltage of such an electrical machine as a differential input signal, so that zero crossings of this input signal in flanks of the rectangular output signal

being transformed. An evaluation of these edges or their time intervals from one another advantageously makes it possible to draw conclusions about the speed of the internal combustion engine. A phase of an electrical machine of a vehicle is therefore advantageously connected to the first and second input connection. Is at the first and second potential connection advantageously a battery connected, preferably one

Vehicle battery.

The circuit arrangement thus provides in particular a circuit

Obtaining speed information of an internal combustion engine from electrical signals of an electrical machine coupled to this circuit arrangement. For this purpose, the

Circuit arrangement, in particular extracting information from the electrical signals of such an electrical machine and providing them in a suitable form for digital evaluation in a computing unit, for example in the form of a control unit or

Engine control unit. The circuit arrangement is thus particularly suitable for methods for determining a rotational speed of a crankshaft

Internal combustion engine as described in DE 10 2014 206 173 A1 or

DE 10 2016 221 459 A1 are shown.

The circuit arrangement advantageously also has a

Signal processing unit for filtering the input signal. In particular, this signal processing unit of the signal evaluation unit is in the

Input signal path upstream. The signal processing unit functions in particular as a filter, for example as a low-pass filter. With the aid of the signal processing unit, interference in particular can thus be removed from the input signal in order to evaluate the

Allow input signal. The signal processing unit has, for example, two resistance elements and a capacitor.

The circuit arrangement preferably also has one

Signal conditioning unit for conditioning the input signal. This signal processing unit is preferably the signal processing unit in the

Input signal path upstream. The signal processing unit can in particular process the input signal to enable processing in the subsequent circuit parts. In particular, the input signal can be provided with a voltage offset by the signal processing unit in order to follow it into an optimal operating point Shift circuit parts. The signal processing unit has, for example, four resistance elements and three capacitors.

The circuit arrangement preferably also has a limiting unit for limiting the voltage and the current of the input signal.

This limiting unit is preferably connected upstream of the signal processing unit in the input signal path. Depending on the voltage amplitude or power of the input signal, its voltage and current can be adjusted using the

Limiting unit are limited at the beginning, so as not to overload or damage the subsequent circuit parts. The

Limiting unit has, for example, two resistance elements and two diodes.

The circuit arrangement advantageously has both the

Limiting unit as well as the signal processing unit and

Signal processing unit on. The signal processing unit is

advantageously downstream of the limiting unit and the

The signal processing unit is advantageously connected downstream of the signal processing unit.

Further advantages and refinements of the invention result from the description and the attached drawing.

The invention is illustrated schematically in the drawing using exemplary embodiments and is described below with reference to the drawing.

Brief description of the drawings

Figure 1 shows schematically a preferred embodiment of a

Circuit arrangement according to the invention as a blockidagram.

Figure 2 shows schematically a preferred embodiment of a

Circuit arrangement according to the invention as a circuit diagram. Figure 3 shows schematically a preferred embodiment of a

Rectifier circuit as a circuit diagram.

Figure 4 shows schematically a preferred embodiment of a

Circuit arrangement according to the invention as a circuit diagram.

Embodiment (s) of the invention

Identical reference symbols in the figures denote identical or identical elements.

In Figure 1 is a preferred embodiment of an inventive

Circuit arrangement 100 is shown schematically as a block diagram. The individual function blocks shown in FIG. 1 represent different circuit parts of the circuit arrangement 100.

The circuit arrangement 100 has a first potential connection V + and a second potential connection V- for connection to a

Supply voltage on.

A first function block 110 is for supply to the subsequent ones

Function blocks provided. Depending on the supply voltage source connected to the V + and V- potential connections, this can

Supply voltage are stabilized accordingly and their

Voltage level are adjusted to enable stable operation of the subsequent circuit parts. For this purpose, function block 110 can include, for example, support capacitances, voltage regulators, voltage or current limiters (in particular resistance).

Furthermore, the circuit arrangement 100 comprises a first input connection In + and a second input connection In- for feeding a differential input signal into an input signal path, which is one of the function blocks 120, 130, 140, 150 and 160 rectangular output signal is converted, which at a

Output connector Out is output.

Function block 120 is provided as a limiting unit for voltage and / or current limitation. Depending on the voltage amplitude or power of the input signal, it may be necessary to limit its voltage and current on the input side with the aid of function block 120 in order not to overload or damage the subsequent circuit parts.

Function block 130 is provided as a signal processing unit. It may be necessary to process a limited input signal to enable processing in the subsequent steps. For example, the function block 130 can provide the input signal with a voltage offset for this purpose in order to shift it into an optimal operating point of subsequent blocks.

Function block 140 is provided as a signal processing unit. To enable usable evaluation of the signal, interference can be removed from the input signal in function block 140 using a filter, e.g. using a low pass filter.

Function block 150 is designed as a signal evaluation unit. The circuit arrangement 100 is provided to show at its output whether the input signal has a positive or negative potential difference. For this purpose, the input signal is evaluated or converted in the function block 150 in such a way that zero crossings of the input voltage are output at the output as (steepest possible) signal edges, so that a rectangular output signal arises from any input signal, which is the sign of the input voltage by its Level and the zero crossings of the input voltage as rising or falling edges. A positive sign of the input voltage is shown in particular as a high level and a negative sign in particular as a low level. For this purpose, 150 in particular evaluated which sign the input voltage has and generates a corresponding signal for the output stage.

In the function block 160, the output signal can be amplified accordingly depending on the required output voltage and output power and can be output at the output of the circuit arrangement 100.

Figure 2 shows schematically a preferred embodiment of a

Circuit arrangement 100 according to the invention as a circuit diagram.

An amplifier circuit here having an operational amplifier OPV and a resistance element R10 and a capacitor C6 represents the signal evaluation unit or the function block 150

Input signal path is a first input of the operational amplifier OPV connected to the first input connection ln + and a second input of the operational amplifier OPV is connected to the second input connection In-. A first supply voltage connection of the operational amplifier OPV is connected to the first potential connection V + and a second one

Supply voltage connection of the operational amplifier OPV with the second potential connection V-. An output of the operational amplifier OPV is connected to the output connection Out via an output signal path. Furthermore, the output of the operational amplifier OPV is via the

Resistor element R10 and the first capacitor C6 connected to the first input of the operational amplifier OPV or fed back.

A resistance element R1 is the first potential connection V +

downstream and serves together with a capacitor C5 as

Function block 110 for current limitation and voltage stabilization for the voltage supply. The capacitor C5 is in parallel with the

Supply connections of the operational amplifier OPV connected between the first potential connection V + and the second potential connection V-. If the power requirement of the circuit arrangement 100 is so low that a current limitation for the source connected to V +, V- is not necessary, the resistance element R1 can also be omitted. If the Voltage is sufficiently stable so that the buffer effect of the capacitor C5 is not required, it can also be omitted.

The delimitation unit or the function block 120 has two

Input connections and two output connections in the input signal path and is realized in the form of two resistance elements R2 and R3 and two diodes D1 and D2. The resistance element R2 is between a first input connection and a first output connection

Limiting unit switched, the resistance element R3 between a second input terminal and a second output terminal of the

Limitation unit. An anode of diode D1 is with the first

Resistor element R2 is connected and a cathode of this diode D1 to the second potential connection V-. Accordingly, an anode of the diode D2 is connected to the second resistance element R3 and the cathode of this diode D2 is connected to the second potential connection V-. Diodes D1 and D2 limit positive input voltages to theirs

Forward voltage (typically 0.3-0.7 volts). If additional limitation of negative voltages is desired, antiparallel diodes can be added to the diodes D1 and D2. Their cathodes would then be with the resistors R2 or R3 and their anodes with the

Potential connection V- connected.

The dimensioning of the resistance elements R2 and R3 can take place depending on the expected maximum input voltage and the associated power loss that may occur at the diodes D1 and D2.

In particular, the resistance elements R2 and R3 and the diodes D1 and D2 are each dimensioned identically.

The signal processing unit or the function block 130 has two

Input connections and two output connections in the input signal path and is realized in the form of with four resistance elements R4, R5, R6, R7 and three capacitors C1, C2, C3. The resistance elements R6 and R7 are connected as voltage dividers in parallel between the first potential connection V + and the second potential connection V-. The capacitor is C1 switched between a first input connection and a first output connection of the signal processing unit and on the input side with the

Resistor element R2 connected. Accordingly, the capacitor C2 is between a second input terminal and a second one

Output connection of the signal processing unit switched and

connected on the input side to the resistance element R3. Furthermore, the first capacitor C1 is connected to the resistance element R6 via the resistance element R4 and the capacitor C2 is connected to the resistance element R7 via the resistance element R5. The capacitor C3 is also connected to a point between the resistance elements R6 and R7 and to the second potential connection V-.

In particular, the capacitors C1, C2, C3 and the resistors R4, R5, R6, R7 are used to provide the input signal limited on the input side with an offset voltage. This offset voltage is selected in particular in this case via the voltage divider R6, R7 so that the differential input signal to be evaluated lies in a suitable range for the subsequent operational amplifier OPV.

The capacitor C3 serves to stabilize the offset voltage. The capacitors C1 and C2 pull the limited input voltages to the level of the offset voltage. The dimensioning of these two capacitors C1 and C2 is chosen so large that even for low ones

Input frequencies no saturation of the capacitors occurs and the

Voltage fluctuations at the input are also retained in the voltage provided with an offset before the subsequent resistance elements R8 or R9.

The resistance elements R4 and R5 serve the predetermined

Offset voltage between the resistor elements R6 and R7 by

Relieve the charging processes of capacities C1 and C2. They act as a current limit and thus stabilize the offset voltage. In particular, the resistance elements R4 and R5 and the capacitors C1 and C2 are each dimensioned identically. The signal processing unit or the function block 140 has two

Input connections and two output connections in the input signal path and is in the form of two resistance elements R8 and R9 and one

Capacitor C4 realized. The resistance element R8 is between a first input connection and a first output connection

Signal processing unit switched and connected to the capacitor C1. Accordingly, the resistance element R9 is between a second

Input port and a second output port of

Signal processing unit switched and connected to the capacitor C2. The capacitor C4 is between the two output terminals of the

Signal processing unit switched. In particular, this capacitor is thus connected upstream of the operational amplifier OPV and expediently connected in parallel to the input connections of the operational amplifier.

The differential, offset-shifted input signal is filtered via the resistors R8, R9 and the capacitor C4. This filter behaves in particular like a low-pass filter and is expediently used for high-frequency noise on the input signal, which is caused by

To suppress ambient noise etc. on the signal lines at the input. The dimensioning takes place in such a way that the highest expected frequency of the input signals is not yet in the

The filter's damping range falls. In particular, the resistance elements R8 and R9 are dimensioned identically.

The operational amplifier OPV indicates at its output by a voltage at the level of its positive supply voltage that the difference in its input signals is positive, and by a voltage at the level of its negative supply voltage that the difference in its input signals is negative. This means that the input is switched whenever the sign of the difference in the input signals changes, i.e. there is a zero crossing in the differential input signal. By the offset shift of the input signals in the optimal

Operating point of the operational amplifier OPV can be used in this circuit, an operational amplifier without negative

Supply voltage needs. The poles of a vehicle battery can thus be connected to V + and V- and no further adjustment of this voltage has to be carried out.

The output of the operational amplifier OPV is fed back via the resistor R10 and the capacitor C6 to the first input of the operational amplifier OPV. As a result, each time the output is switched, a short pulse is given to the first input, and thus its

Voltage level changed significantly compared to the other input. The deflection always takes place in the direction of the expected difference of the input signals after switching the output, so that a quick switching of the output due to signal noise in the area of very small voltage differences at the inputs is avoided. The

Feedback thus suppresses noise influences in the area of the zero crossings of the differential input signal and serves as a further security in addition to the low-pass filter.

The dimension of the resistance element R10 and the capacitor C6 in particular selects the pulse length in such a way that the pulse is safely over before a new zero crossing of the differential voltage is also present at the inputs for the maximum frequency to be expected.

The capacitor C5 serves to stabilize the supply voltage of the operational amplifier OPV and should be placed as close as possible. Suitable dimensions can be proposed, for example, in data sheets of the selected operational amplifier OPV.

The first supply voltage connection of the operational amplifier OPV can also be connected via a resistance element R11 to the output of the

Operational amplifier OPV connected. The output signal Out can be current limited via this resistance element R11 to subsequent ones To protect circuits. In addition, this resistance element R11 is used in particular to deliver a defined signal state at the output for high level when using an operational amplifier with an open collector output.

If the output voltage at the output Out should not exceed a certain value, for example a Zener diode with a corresponding Zener voltage can be connected to limit the voltage between the output Out and the potential connection V-, the anode being connected to the

Potential connection V- and the cathode is connected to the output Out, or the resistor R11 is not placed between the supply voltage and the output Out, but instead a corresponding voltage is applied instead of the supply voltage.

If a higher stability of the offset voltage is required, which can be achieved with the

Resistance elements R6 and R7 is generated, the resistance element R7 can be replaced by a Zener diode with the desired Zener voltage, the anode with the potential connection V- and the cathode with

Resistor element R4 or R6 is connected. In this case, the resistance element R6 acts as a current limiter to protect the Zener diode and as a setting parameter for its operating point and no longer as part of a voltage divider.

In a particularly advantageous manner, the circuit arrangement 100 is suitable for use in a vehicle in order to convert an electrical signal from an electrical machine or a generator of the vehicle as a differential, analog input signal into a digital output signal. In particular, a phase current or a phase voltage of a phase of such an electrical machine can be used as an input signal. Since such an electrical machine is particularly coupled to an internal combustion engine of the vehicle, the speed of the internal combustion engine can be inferred from characteristic features of this input signal, in particular from the zero crossings or from their time intervals. The rectangular output signal of the circuit arrangement 100 can therefore, for example, be one Control unit of the vehicle can be fed to a determination of the speed.

FIG. 3 shows a preferred embodiment of a rectifier circuit 200, which can preferably be used as part of a circuit arrangement 100 according to the invention, in particular when used in a vehicle. Figure 4 shows such a preferred embodiment of an inventive

Circuit arrangement 100 in such use in a vehicle. An electrical machine of the vehicle is designated 210 and exemplified as a single-phase electrical machine, but can be seen in FIG

correspondingly, for example, also be designed as a three-phase electrical machine. In particular, the electrical machine 210 is as one

Three-phase alternator designed and with a crankshaft

Internal combustion engine of the vehicle coupled, for the sake of

Clarity is not explicitly shown in Figure 3. In particular, the electric machine 210 is provided for charging a battery that

in particular designed as a motor vehicle battery and can be part of an electrical system. Connections of this battery are labeled B + and B- in FIG.

This vehicle battery B +, B- is also connected to the potential connections V + and V- of the circuit arrangement 100 (FIG. 4) as a supply voltage

connected. One is at the first input connection In + and the second input connection In- in the circuit arrangement 100

Phase winding of the electrical machine 210 connected, the phase voltage of this phase winding is supplied to the circuit arrangement 100 as a differential input signal.

The circuit arrangement 100 according to the present invention is particularly advantageously suitable for being used in combination with a

Rectifier circuit to be used, as shown schematically in Figure 3 and designated 200.

Such a rectifier circuit 200 is in the patent application filed on the same day "Circuit arrangement and rectifier circuit for one electrical machine "of the applicant, to which reference is made with regard to details of such a rectifier circuit and the content of which is hereby fully made the content of this application.

The rectifier circuit 200 is provided to rectify an AC voltage generated by the electrical machine 210 and provided at outputs Vgen + and Vgen- into a DC voltage which can be used to charge the vehicle battery.

For this purpose, the rectifier circuit 200 has one

Bridge rectifier 220 consisting of highside switches 200a, 200b and low-side switches 200c, 200d.

These switches 200a, 200b, 200c, 200d are each designed according to a particularly advantageous embodiment as a circuit arrangement in which a switching transistor M201 is controlled with the aid of a control circuit such that this switching transistor M201 in a first direction from a first to a second of its connections conducts, in particular from a source connection to a drain connection in the case of a MOSFET, and blocks in an opposite direction from the second to the first connection.

The switches 200a, 200b, 200c, 200d expediently make it possible to operate the respective switching transistor analogously to a diode and to emulate the behavior of a diode with the respective switching transistor, which, however, has significantly lower power losses than a diode. In particular, the switches 200a, 200b, 200c, 200d can be used in the rectifier circuit 200 instead of diodes, as a result of which power losses and a need for cooling elements can be reduced.

In the individual switches 200a, 200b, 200c, 200d, the respective control circuit for controlling the corresponding switching transistor M201 each comprise a large number of components, in particular a diode D201,

Resistor elements R201, R202, R203, R204, R205, capacitors C201, C202 and other transistors, for example in the form of bipolar transistors Q201, Q202, Q203, Q204. With regard to the purpose of these various components and further details of such switches 200a, 200b, 200c, 200d, reference is made to the applicant's parallel patent application mentioned here.

Furthermore, the rectifier circuit 200 has a short-circuit unit 230, which can control the switches 200a, 200b, 200c and 200d in such a way that a short-circuit of the phases of the electrical machine 210 is generated. Such a short circuit can e.g. triggered by an external control device, which can send a control signal or short circuit signal KS to the rectifier circuit 200, for example at a signal input. It is also conceivable that such a short circuit signal by an internal

Monitoring unit is triggered. Such a short circuit can be used so that in the case of a fully charged battery, it cannot be charged further and thus not overcharged.

The decision about a short circuit is not made by an external

Control unit hit, for example because the communication line between the short-circuit unit and the control unit is defective, is also used

Failure Protection Unit 240 to make this decision. For this purpose, the fault protection unit 240 monitors the output voltage of the

Rectifier circuit 200 and thus in particular the battery voltage. When a predeterminable threshold value is reached, the error protection unit expediently triggers a short circuit in the electrical machine. The fault protection unit can also end the short circuit again if safe operation is ensured again.

For example, a control signal Off1 can be transmitted from the short-circuit unit 230 to the switch 200a in order to generate such a short circuit and a control signal Off2 to the switch 200b in order to permanently block these highside switches. Furthermore, a control signal On3 can be transmitted from the short-circuit unit 230 to generate a short-circuit to the switch 200c and a control signal On4 to the switch 200d in order to switch these low-side switches permanently on. Thanks to the fully conductive lowside Switches 200c, 200d expediently short-circuit the phase connections of the electrical machine 210 and the blocking highside switches 200a, 200b expediently decouple the electrical machine 210 from the battery. Thus, this is not short-circuited and at the same time further current flow from the electrical machine into the battery is prevented and overcharging is avoided. In this case, the battery can discharge itself, for example, via an electrical system. The short-circuit condition is expediently ended as soon as there is no further danger of overloading.

The short-circuit unit 230 and the error protection unit 240 expediently comprise a large number of components, in particular transistors, e.g. MOSFETs, M205, M206, M207, M208, resistance elements R225, R226, R227, R228, R229, a diode R205 and a capacitor C229. Also with regard to the purpose of these different components and other details of the

Short-circuit unit 230 and error protection unit 240 are referred to the applicant's parallel patent application mentioned here.

In a particularly advantageous manner, a preferred embodiment of a circuit arrangement according to the present invention in combination with an embodiment of a rectifier circuit, as disclosed in the applicant's parallel patent application mentioned, can be used to implement an overall circuit by which an electrical machine in a vehicle rectify the generated phase voltage and use it to supply a battery or an electrical system, and also to use the phase voltage or the phase current of the electrical machine simultaneously to determine the speed of a crankshaft of an internal combustion engine coupled to the electrical machine. In particular, regulation of the output voltage of the electrical machine and extraction of

Speed information from the phase signals of the electrical machine are made possible with a single circuit arrangement. In particular, the circuit arrangement and the rectifier circuit can be implemented as a common structural unit, e.g. as a common integrated circuit (IC, ASIC), which in particular saves component costs and board space.

Claims

Expectations

1. Circuit arrangement (100) for converting a differential

Having input signal in a rectangular output signal

a first input port (ln +) and a second

Input connection (In-) for feeding the differential input signal into an input signal path,

a first potential connection (V +) and a second

Potential connection (V-) for connection to a supply voltage, an output connection (Out) for outputting the rectangular output signal,

a signal evaluation unit (150) with a first input, a second input and an output, which is set up to show at its output whether an input signal has a positive or negative potential difference between the first input and the second input,

where the first input of the

Signal evaluation unit (150) with the first input connection (ln +) and the second input of the signal evaluation unit (150) with the second input connection (In-) are connected, and

the output of the signal evaluation unit (150) with the

Output connector (Out) is connected.

2. Circuit arrangement (100) according to claim 1, wherein the

Signal evaluation unit (150) has an amplifier circuit (OPV) with a first input, a second input and an output, the output of the amplifier circuit (OPV) via a resistance element (R10) and a capacitor (C6) with the first input of the

Amplifier circuit (OPV) is connected.

3. The circuit arrangement (100) according to claim 1 or 2, further comprising a signal processing unit (140) with two in the input signal path

Input ports and two output ports, with two

Resistance elements (R8, R9) and a capacitor (C4),

a first resistance element (R8) of these two

Resistance elements (R8, R9) is connected between a first input connection and a first output connection of the signal processing unit,

a second resistance element (R9) of these two

Resistor elements (R8, R9) is connected between a second input connection and a second output connection of the signal processing unit and

the capacitor (C4) being connected between the two output connections of the signal processing unit.

4. Circuit arrangement (100) according to one of the preceding claims, further comprising in the input signal path a signal conditioning unit (130) with two input connections and two output connections, with four resistance elements (R4, R5, R6, R7) and three capacitors (C1, C2, C3) ,

a first resistance element (R6) and a second

Resistance element (R7) of these four resistance elements (R4, R5, R6, R7) are connected in parallel as voltage dividers between the first potential connection (V +) and the second potential connection (V-),

a first capacitor (C1) of these three capacitors (C1, C2, C3) between a first input terminal and a first

Output connection of the signal processing unit is switched,

a second capacitor (C2) of these three capacitors (C1, C2, C3) between a second input terminal and a second

Output connection of the signal processing unit is switched,

the first capacitor (C1) of these three capacitors (C1, C2,

C3) via a third resistance element (R4) of these four

Resistance elements (R4, R5, R6, R7) with the first and second Resistance element (R6, R7) of these four resistance elements (R4, R5, R6, R7) is connected,

the second capacitor (C2) of these three capacitors (C1, C2, C3) via a fourth resistance element (R5) of these four

Resistance elements (R4, R5, R6, R7) with the first and second

Resistance element (R6, R7) of these four resistance elements (R4, R5, R6, R7) is connected and

a third capacitor (C3) of these three capacitors (C1, C2, C3) with a point between the first resistance element (R6) and the second resistance element (R7) and with the second

Potential connection (V-) is connected.

5. Circuit arrangement (100) according to one of the preceding claims, further comprising in the input signal path a limiting unit (120) with two input connections and two output connections, with two

Resistance elements (R2, R3) and two diodes (D1, D2),

a first resistance element (R2) of these two

Resistor elements (R2, R3) is connected between a first input connection and a first output connection of the limiting unit, a second resistance element (R3) of these two

Resistance elements (R2, R3) is connected between a second input connection and a second output connection of the limiting unit,

wherein an anode of a first diode (D1) of these two diodes (D1, D2) is connected to the first resistance element (R2) of these two resistance elements (R2, R3), and wherein a cathode of this first diode (D1) is connected to the second potential connection ( V-) is connected,

wherein an anode of a second diode (D2) of these two diodes (D1, D2) is connected to the second resistance element (R3) of these two resistance elements (R2, R3), and wherein a cathode of this second diode (D2) is connected to the second potential connection ( V-) is connected.

6. Circuit arrangement (100) according to claim 3, 4 and 5, wherein the

Signal processing unit (130) of the limiting unit (120) in Input signal path is downstream and the

Signal processing unit (140) is connected downstream of the signal processing unit (130) in the input signal path,

the first resistance element (R2) of the two

Resistance elements (R2, R3) of the limiting unit (120) with the first capacitor (C1) of the three capacitors (C1, C2, C3)

Signal processing unit (130) is connected,

wherein the first capacitor (C1) of the three capacitors (C1, C2, C3) of the signal processing unit (130) is connected to the first resistance element (R8) of the two resistance elements (R8, R9) of the signal processing unit (140),

the second resistance element (R3) of the two

Resistance elements (R2, R3) of the limiting unit (120) with the second capacitor (C2) of the three capacitors (C1, C2, C3)

Signal conditioning unit (130) is connected, and

wherein the second capacitor (C2) of the three capacitors (C1, C2, C3) of the signal processing unit (130) is connected to the second resistance element (R9) of the two resistance elements (R8, R9) of the signal processing unit (140).

7. Circuit arrangement (100) according to one of the preceding claims, wherein the first supply voltage connection of the signal processing unit (150) is further connected via a resistance element (R11) to the output of the signal processing unit (150).

8. Circuit arrangement (100) according to one of the preceding claims, wherein the first potential connection (V +) is followed by a resistance element (R1) and / or wherein a capacitor (C5) between the first potential connection (V +) and the second potential connection (V-) is switched.

9. Circuit arrangement (100) according to one of the preceding claims, wherein at the first input terminal (ln +) and the second

Input connection (In-) a phase of an electrical machine (210) is connected, in particular an electrical machine

Vehicle.

10. The circuit arrangement (100) according to claim 9, wherein the phase of

electrical machine (210) a rectifier circuit (200)

is connected downstream.

11. Circuit arrangement (100) according to one of the preceding claims, wherein a battery (B + - B-) is connected to the first potential connection (V +) and the second potential connection (V-), in particular a

Vehicle battery.