WO2014060184A1

WO2014060184A1 - Control circuit for at least two contactors and method for operating at least two contactors

Info

Publication number: WO2014060184A1
Application number: PCT/EP2013/069669
Authority: WO
Inventors: Chrysanthos Tzivanopoulos; Dirk Hasenkopf
Original assignee: Robert Bosch Gmbh; Samsung Sdi Co., Ltd.
Priority date: 2012-10-18
Filing date: 2013-09-23
Publication date: 2014-04-24
Also published as: KR101771625B1; DE102012218983A1; CN104737262B; KR20150058434A; JP2015535129A; JP6023341B2; CN104737262A

Abstract

The invention relates to a control circuit (30) for at least two contactors, which comprises at least one first outlet (15) and at least two second outlets (16) which enable said control circuit (30) to be connected to the connections of at least two control bobbins for at least two contactors. Said control circuit (30) also comprises a holding voltage unit (10) which is connected to the at least one first outlet (15) via the outlet (6) and is designed to provide on the outlet (6), a holding voltage for adjusting a holding current for the control bobbins. Said control circuit (30) further comprises a regulating circuit (20) which is connected to the electric connections (8) and to the inlet (9) of the holding voltage unit (10) and is designed to generate a control signal which is dependent on the currents circulating in the electric connections (8) and to transmit to the holding voltage unit (10). The invention relates to a method for operating at least two contractors.

Description

Description title

Control circuit for at least two contactors and a method for operating at least two contactors

The present invention relates to a drive circuit for at least two contactors, which has a control circuit with which the currents are controlled by the drive coils of the contactors.

State of the art

It is becoming apparent that in the future both in stationary applications as well as in vehicles such as hybrid and electric vehicles increased

Battery systems are used, to which very high

Reliability requirements are made. The background to this is that failure of the battery can lead to a safety-relevant problem. In order to provide the desired for a particular application services available, usually a high number of battery cells are connected in series, resulting in a high output voltage of the battery, which is applied without suitable measures permanently to the corresponding supply lines of the device powered by the battery and can endanger maintenance personnel or users. For this reason, contactors are usually provided in order to decouple the battery can electrically. In motor vehicles with electric

Drive motors are usually installed on both the plus pole and the negative pole of the battery contactors, which are designed for the high voltage of the battery and must be able to reliably disconnect the battery even with short-circuit currents of over 1000 A. The switching on and off of the contactors usually takes place via an electronic output stage or via a drive circuit, which the drive coils of the contactors are supplied with power. The drive power is not negligible. When switching on, however, far higher driving currents are required for reliably tightening the contactors than for subsequently holding the contacts in the closed position

Status. For this reason, it is customary to control the contactors in two

Subdivide modes, the suit mode and the hold mode (or suit or hold phase). Significant for the particular mode is the magnitude of the drive current that is higher during the pull-up mode than during the hold mode. This is spoken of the suit and the hold level. The tightening mode is only needed for switching on (closing) the contactors and is of relatively short duration. For the majority of the operating time, the contactors are operated in the more power-saving holding mode. A drive circuit for activating contactors should therefore be able to represent both operating modes.

From DE 10 2010 041 018 A1 a device for driving a contactor is known, which comprises a holding current unit which is designed to output a holding current for the drive coil of a contactor to one of its output side outputs. With the device disclosed in DE 10 2010 041 018 A1, the actuation of at least one contactor during the tightening phase and the holding phase with different

Voltage levels of constant voltages can be made in an advantageous manner. However, the components used, for example, within the apparatus disclosed in DE 10 2010 041 018 A1, have in particular the

Winding resistors of the drive coils of the contactors, a

Temperature dependence and each a production-related dispersion of their component parameters. Further, the holding voltage generated by the holding current unit is set to a value set at the time of production. The related components must therefore be designed so that the necessary holding current can be provided even in the presence of extreme temperatures of the holding current unit. However, since the conductivity of the components and thus the current flow through the same, such as by the drive coil of the contactor, fluctuates due to temperature, it is necessary to dimension the components larger than would be necessary for the actual desired current. For example, the components used in the holding circuit of the device disclosed in DE 10 2010 041 018 A1 must be dimensioned larger by up to 66% for this reason, which greatly increases the necessary installation space and the costs for the components.

Disclosure of the invention

According to the invention, a drive circuit is provided for at least two contactors, which comprises a first and a second terminal, via which the drive circuit can be connected to the poles of an energy store. Furthermore, the drive circuit comprises at least one first output and at least two second outputs, via which the

Control circuit with the terminals of at least two Ansteuerspulen for at least two contactors is connectable. The at least two second outputs are connected via an electrical connection to the second terminal. Furthermore, the drive circuit comprises a

Holding voltage unit having an output and an input for receiving a control signal and which has its output with the

connected to at least one first output and is adapted to provide a holding voltage for setting a holding current for the Ansteuerspulen at its output. According to the invention, the drive circuit has a control circuit which is connected to the electrical connections and the input of the holding voltage unit and is adapted to generate a control signal dependent on the currents flowing in the electrical connections and to transmit them to the holding voltage unit.

An advantage of such a drive circuit is that on the control circuit, a readjustment of the holding voltage unit in response to the current flowing through the drive coils of the contactors currents is possible. Thus, the holding voltage provided by the holding voltage unit

or caused by the provided holding voltage

Holding current can be set by connected to the drive circuit drive coils in response to the current flow through the drive coils themselves. So it can be guaranteed that the current through the

Control coils is precisely adjustable at any time. The components used for the realization of the drive circuit then no longer have to be over-dimensioned provisionally, whereby the cost and the necessary space for the realization of the drive circuit can be greatly reduced.

In a preferred embodiment, the holding voltage unit is designed to change the amount of the holding voltage provided at its output upon receipt of a control signal corresponding to this control signal. As a result, for example, a linear control of

Holding voltage unit or the provided holding voltage and thus the output in the first output holding current possible. The type of control signal determines the type of change of the

Holding current.

The control circuit preferably comprises a minimum current selection circuit which has an output and is designed to measure the actual values of the currents flowing through the electrical connections and to output the minimum of the measured actual values of the currents I _min via its output.

Preferably, the minimum current selection circuit has a resistor and each electrical connection to a respective diode, wherein in each case an electrical connection to the cathode of a respective diode is connected and wherein the anodes of the diodes are connected to a terminal of the resistor. By such a diode circuit, a minimum current selection can be realized because at the output of the diode circuit always the smallest of the input values applied to the input is output.

Particularly preferably, the minimum current selection circuit has a

Resistor and each electrical connection to a precision rectifier with two inputs and an output, wherein in each case an electrical connection is connected to one input of a precision rectifier, while the respective other input of the respective precision rectifier is fed back to the output of the respective precision rectifier, the outputs all precision rectifiers with a connection of the

Resistance are connected. The precision rectifiers are preferably designed as feedback operational amplifiers, the feedback branches of the

Operational amplifier each having a diode, wherein the cathodes of the diodes are respectively connected to the output of their respective operational amplifier, while the anodes of the diodes with the inverting

Input of their respective operational amplifier are connected. By such a precision rectifier circuit can also be a

Realize minimal current selection and also compensate for the forward voltage of the built-in diodes at room temperature, that is, the offset of the diodes. As a result, a miniature current selection circuit realized by precision rectifiers with diodes can be provided, with which a very accurate measurement of the actual values of the currents through the electrical connections is possible. Furthermore, the ones related here

Short-circuit proof operational amplifiers, do not require frequency compensation, have large input voltage ranges, and consume little power.

In a preferred development of one of the preceding

Embodiments, the control circuit comprises a first control circuit whose input is connected to the output of the minimum current selection circuit and whose output is connected to the input of the holding voltage unit.

Preferably, this first actuating circuit is adapted to compare a current flowing in its input with a reference value and to generate depending on the result of this comparison, a first control signal for setting a holding voltage for the holding voltage unit and to the

To transmit holding voltage unit. As a result, an external control loop is realized within the drive circuit, which operates with the recirculated holding current through the drive coils and can be understood as an external, superimposed current regulator. In a preferred further development of this embodiment corresponds to

Reference value to the minimum necessary holding current l _Hm in the contactor to be controlled. This makes it possible to regulate the holding voltage unit so that the holding voltage provided by them or the holding currents generated by them by the drive coils of the contactors connected to the drive circuit always have an amount which is equal to or greater than the minimum necessary holding current l _Hm in , l _Hm in is the one stream, which at least must flow through the Ansteuerspulen to keep the respective contactors during the holding phase in the attracted state.

In a preferred further development of this embodiment, the first control signal always corresponds to that necessary for setting a minimum necessary holding voltage at the output of the holding voltage unit

Control signal for the holding voltage unit. In this way it can be further ensured via the second control circuit that always flows through the Ansteuerspulen the minimum necessary holding current iHmin. By such

Embodiment, disturbances that interfere with the inner control loop, for example, fluctuations in the input voltage of the holding voltage unit, also be corrected directly on this route. The inner control loop reacts directly to deviations of the holding voltage provided by the holding voltage from the setpoint, without this having to lead to a deviation of the holding current through the Ansteuerspulen and thus to an interfering in the outer control loop disturbance. The minimum necessary holding voltage corresponds to that voltage at the output of the holding voltage unit, which is needed in each with the

Control circuit connected to the drive coil of a contactor to cause the flow of a current whose amount is at least the minimum

necessary holding current l _Hm in corresponds.

Preferably, the control circuit comprises a second control circuit which is designed to provide the first control signal generated by the first control circuit with the one provided at the output of the holding voltage unit

To compare holding voltage and depending on the result of this comparison, the first control signal to superimpose a further control signal. As a result, an inner control loop is implemented within the drive circuit, which is provided with the one provided at the output of the holding voltage unit

Holding voltage works and can be considered as an internal, subordinate voltage regulator. In this case, the control or input variable of the second actuating circuit is the first control signal generated by the first actuating circuit. The inner control loop thus derives its input values from the outer control loop. Preferably, the average duration T ₂ , which between the generation of two successive further control signals by the second

Actuator is a factor X less than the average duration ΤΊ, which between the generation of two consecutive first

Control signals through the first control circuit, where 0 <X <1 applies. As a result, the time behavior of the first and the second control circuit can be defined with respect to each other via X, the first control circuit always operating slower than the second control circuit. In other words, in such an embodiment, the inner control loop is faster than the outer control loop. Thus, a first control signal generated and transmitted by the first control circuit can always be checked by the second control circuit and corrected if necessary.

Preferably, the holding voltage unit is designed as a switching converter.

Furthermore, a method is provided for operating at least two contactors, which comprises at least two drive coils for driving at least two contactors and a holding voltage unit which is connected to the at least two drive coils and designed to a current flow through the at least two by a holding voltage generated at its output

To cause drive coils. The method includes the following

Method steps: Provision of a pull-in current flowing through the at least two drive coils by the holding voltage unit. Providing a holding current flowing through the at least two drive coils through the holding voltage unit. Compare the by the at least two

Ansteuerspulen flowing holder currents with each other and / or selection of the minimum of the at least two Ansteuerspulen flowing

Holding currents. Compare the minimum of the holding currents with a

Reference current. Generating a first control signal for the

Holding voltage unit for controlling the holding voltage at the output of

Holding voltage unit depending on the result of the comparison between the minimum of the holding currents flowing through the at least two Ansteuerspulen with the reference current. Compare the first

Control signal with the present at the output of the holding voltage unit holding voltage. Generating a second control signal for the

Holding voltage unit for controlling the holding voltage at the output of Holding voltage unit depending on the result of the comparison between the first control signal and the output of the

Holding voltage unit present holding voltage.

Preferably, the attraction current has a larger amount than the holding current. Advantageous developments of the invention are specified in the subclaims and described in the description.

drawings

Embodiments of the invention will be explained in more detail with reference to the drawings and the description below. Show it:

1 shows a drive circuit of the prior art,

Figure 2 shows an embodiment of a drive circuit according to the invention for two contactors, and

Figure 3 shows a specific embodiment of an inventive

Drive circuit.

Embodiments of the invention

1 shows a drive circuit 30 of the prior art is shown. The drive circuit 30 for driving two contactors, of which in each case only the drive coils 50 are shown, is connected via a first and a second terminal 11, 12 to a voltage source 60, which supplies the drive circuit 30, but also the current controlled by the drive circuit 30 provides for the activation of the contactors. The

Drive coils 50 of the contactors are connected to the drive circuit 30 via a first output 15 and two second outputs 16. The

Drive circuit 30 has a first switch 41 and two second switches 42, wherein the first switch 41 is connected between the first pole of the voltage source 60 and the first output 15 of the drive circuit 30, while the two second switches 42 each between the second pole

Voltage source 60 and one of the second outputs 16 of the Control circuit 30 are connected, ie within each of an electrical connection 8, each lie between one of the outputs 16 and the second terminal 12. When the three switches 41, 42 are simultaneously closed, the drive coils 50 are directly connected to the voltage source 60 and a maximum current begins to flow which is large enough to attract the contactors of the drive coils 50, so that the contactors in the pass over the conductive state.

The drive circuit 30 also has a holding voltage unit 10, which is also supplied by the voltage source 60. The

Holding voltage unit 10 causes the flow of a holding current, which ensures during the holding phase following the tightening phase, that the contactors remain closed. Since in this case a mass inertia of the electromechanical contactors is not to be overcome during the starting phase, a lower current through the drive coils 50 is already sufficient to keep the contactors in the closed state, so that advantageous power can be saved. During the hold phase, therefore, the first switch 41 is opened again (and, if necessary, the holding voltage unit 10 is activated), so that the drive coils 50 are only flowed through by the holding current. The holding current flows through a diode 45, which between the

Holding voltage unit 10 and the drive coils 50 is connected and has the task to prevent current flow in the output of the holding voltage unit 10. In addition, a freewheeling diode 46 is provided in Figure 1, which has a

To provide freewheeling current path for the current flowing in the drive coils 50 in the event of turning off the holding current available. The Ausphase is initiated by the fact that the second switch 42 is opened and

optionally additionally the holding voltage unit 10 are deactivated. Since the Ansteuerspulen 50 counteract due to their inductance of a change in the currents flowing through them, they also effect their

Separation of the supply voltage, a current flow, which now turns on the freewheeling diode 46 and, due to the series connection, the diode 45. Because the second terminals of the Ansteuerspulen 50 must conduct the current, here each creates a high negative voltage, which is used to break through the serving as a clamping voltage elements 47 Zener diodes leads. The current flow in the drive coils 50 decreases rapidly, so that the magnetic field of the drive coils 50 decreases and the respective contactors fall, whereby the contactors are opened. The first switch 41, the second switch 42 and optionally the

Holding voltage unit 10 are controlled by a control unit 35.

FIG. 2 shows an embodiment of a device according to the invention

Drive circuit 30 shown for two contactors. The drive circuit 30 according to the invention has a first and a second terminal 11, 12, via which the drive circuit 30 with the poles of a

Energy storage, for example, with the connections of a

Low-voltage battery, is connectable. Furthermore, the drive circuit 30 according to the invention has a first output 15 and two second outputs 16, via which the drive circuit 30 to the terminals of two

Actuator coils for two contactors is connectable. In this case, the first output 15 is connectable to the respective first ends or the first terminals of two drive coils, while a second end of a first

Drive coil with the first of the second outputs 16 is connectable, while the second end of a second drive coil with the second of the second

Outputs 16 is connectable. The two second outputs 16 are in each case via an electrical connection 8 to the second terminal 12 of the

Drive circuit 30 connected. Furthermore, the inventive

Drive circuit 30, a holding voltage unit 10, which comprises an output 6 and an input 9 for receiving a control signal. On the

Output 6, the holding voltage unit 10 is connected to the first output 15. The holding voltage unit 10 is adapted to a

Hold voltage for setting a holding current for the drive coils to provide at its output 6. In other words, the holding voltage unit 10 is configured to have a via its output 6

To output holding voltage, which in to the drive circuit 30th

Connected drive coils causes a current flow through them.

According to the invention, the drive circuit 30 further comprises a control circuit 20, which on the input side with the electrical connections 8 and

the output side is connected to the input 9 of the holding voltage unit 10.

In other words, the rule formwork 20 is one over each their inputs with one of the electrical connections 8 of the

Drive circuit 30 is connected and connected at its output to the input 9 of the holding voltage unit 10. The control circuit 20 is designed to be one of those in the electrical connections 8 and thus, if connected to the drive circuit 30, flowing in the drive coils

Stream dependent control signal to generate and the holding voltage unit 10 to transmit. In other words, the control circuit 20 is thus designed to generate a control signal dependent on the currents through the electrical connections 8 and to supply them to the holding voltage unit 10 via the input 9. The properties, that is, for example, the

Amplitude of a control signal generated by the control circuit 20, so are dependent on the currents through the electrical connections 8.

The drive circuit 30 according to the invention is not limited to the activation of only two contactors. It can also according to the invention

Control circuits 30 for the control of further, for example 4, 8 or n contactors can be realized, which are thus connectable to more than two drive coils. Figure 3 shows a specific embodiment of an inventive

Drive circuit 30. This essentially shows a drive circuit 30 according to FIG. 1, which is supplemented by a control circuit 20 as shown in FIG. The descriptions of the components apart from this control circuit 20 or the facts and contexts relating to them can be found in the descriptions relating to FIGS. 1 and 2 and FIGS. 1 and 2 themselves. The components identified in the same way in FIG. 3 thus correspond to those of the first exemplary embodiment of FIG. 2 as well as those of the example of FIG

Control circuit 30 of the prior art in the figure 1, so that the statements made there with respect to these components on the second

Embodiment of Figure 3 is to be transmitted. In this embodiment, the drive circuit 30 is connected to two drive coils 50 via its first and second outputs 15, 16, while having its first and second terminals 11, 12 connected to a voltage source

Energy storage 60 is connected. Both the drive coils 50 and the Energy storage 60 are not considered as part of the drive circuit 30, respectively.

In the exemplary embodiment of a drive circuit 30 according to the invention shown in FIG. 3, the same has a control circuit 20, which in turn has a minimum current selection circuit 5 and a first and second control circuit 1, 2. The minimum current selection circuit 5 has in this embodiment, each electrical connection 8 a

Shunt resistance, wherein in each case a shunt resistor within each one of the electrical connections 8, in each case between the

Switching means 42 of the respective electrical connection 8 and the terminal 12 of the drive circuit 30 is located. The minimum current selection circuit 5 is connected with its inputs respectively to the measuring terminals of the shunt resistors, wherein the inputs of the minimum current selection circuit 5 are identical to the inputs of a precision rectifier 7 per electrical connection 8. In other words, the minimum current selection circuit 5 has one for each electrical connection 8

Precision rectifier 7 on, each having an input of a

Precision rectifier 7 via a respective measuring terminal of a

Shunt resistance is connected to one electrical connection 8. Furthermore, the precision rectifier 7 each have a second input and an output, wherein the respective second input is fed back respectively to the output of the respective precision rectifier 7. The minimum current selection circuit 5 also has a Wderstand 4, wherein the outputs of all precision rectifier 7 with the first terminal of this

Resistor 4 are connected. That is, each precision rectifier 7 is connected within the minimum current selection circuit 5 via its respective output to the same terminal of the Wderstandes 4. In this embodiment, the precision rectifier 7 as

executed feedback amplifier, wherein the inverting input of the operational amplifier is fed back respectively to the output of the respective operational amplifier. Within the feedback branches or the feedback of the operational amplifiers, in each case a diode 3 is arranged, whose anode is connected to the respective inverting input of the respective operational amplifier or to the connection of the operational amplifier Resistor 4 is connected, while the cathodes of the diodes 3 are respectively connected to the output of their respective operational amplifier. The other terminal of the resistor 4, with which the precision rectifier 7 are not connected, is connected to the output of the minimum current selection circuit 5, via which the minimum current selection circuit 5 with the

Input of the first control circuit 1 is connected. The

Minimum current selection circuit 5 is adapted to the actual values of the currents flowing through the electrical connections 8, in this

Embodiment, via the shunt resistors to measure and the minimum of the measured actual values of the currents l _min via the output of the

Minimal current selection circuit 5 output. The minimum current selection is in this embodiment via the diodes 3 within the

Precision rectifier 7 realized. At any instant, the lowest of the input values at the precision rectifiers 7 is output via the output of the minimum current selection circuit 5. Both the

Use of shunt resistors for measuring the actual values of the currents and the use of precision rectifiers 7 is optional for the realization of a minimum current selection circuit 5 of a drive circuit 30 according to the invention. The embodiment of the precision rectifier 7 as an operational amplifier with diodes 3 is selected purely by way of example in this embodiment. Control circuits 30 according to the invention may also be implemented with differently designed minimum current selection circuits 5, for example with the exclusive use of diodes 3, whereby the actual values of the currents through the electrical connections 8 can also be measured in a different way than via shunt resistances.

About the output of the minimum current selection circuit 5 selbige transmits the minimum of the measured actual values of the currents l _min to the first control circuit 1, whose output is connected to the input 9 of the holding voltage unit 10. In this exemplary embodiment, the first actuating circuit 1 is designed to compare the minimum of the measured actual values of the currents I _min transmitted via its input with a reference value which, in this exemplary embodiment, is provided purely by way of example by a reference generator 13. In other words, the first control circuit 1 is designed in this embodiment, a fed back into its input

Compare current with a reference value. The reference value is in this embodiment, the minimum necessary holding current l _Hm in the driver to be controlled, that is, the current that must flow at least through the Ansteuerspulen 50 of the contactors, so that they are the contactor in the

Holding state, that is, can hold during the holding phase in the closed state. Furthermore, the first control circuit 1 is designed to be a first control signal for setting a holding voltage for the one, which depends on the result of the comparison between the minimum of the measured actual values of the currents I _min and the minimum necessary holding current I _Hm

Hold voltage unit 10 to generate and to the holding voltage unit 10, via its input 9, to transmit. This corresponds to the first

Actuator 1 generated first control signal in its properties to the result of the comparison. For example, in this exemplary embodiment, the magnitude of the first control signal is greater the more the minimum of the measured actual values of the currents L _n deviates from the minimum holding current l _Hm in. The first control circuit 1 is thus designed in this embodiment, inter alia, in magnitude and duration of the result of the comparison between the minimum of the measured actual values of the currents l _min and a reference value, in this embodiment, the minimum necessary holding current l _Hm in the Sagittarius corresponds, dependent first

To generate control signal and supply the holding voltage unit 10. The

Holding voltage unit 10 is designed in this embodiment, the amount of the holding voltage provided by it at its output 6 and thus the amount of the current flowing in the first output 15 holding current upon receipt of a first control signal, corresponding to this first

Control signal to change. In this embodiment, the

Holding voltage unit 10 purely as an example designed as a switching converter and the first control signal corresponds to a duty cycle, which the

Control level of the switching converter determined. The control of the holding current is done in this embodiment so purely by way of example

Change of the holding voltage at the output of the holding voltage unit 10, corresponding to the obtained first control signal. Furthermore, the drive circuit 30 has a second control circuit 2, which is designed to compare the first control signal generated by the first control circuit 1 with the holding voltage provided at the output 6 of the holding voltage unit 10 and depending on the result of this

Comparison, the first control signal to superimpose a further control signal. With In other words, via the second control circuit 2, the first control signal generated by the first control circuit 1 can be corrected by means of superposition with a correction signal. In this case, the first control signal, which in this embodiment is compared with the holding voltage provided by the holding voltage unit 10, corresponds purely to the example of FIG

Setting a minimum necessary holding voltage at the output 6 of the holding voltage unit 10 necessary control signal for

Holding voltage unit 10. In other words, the first control signal always corresponds to that signal which is connected to the input 9 of the

Holding voltage unit 10 must be applied so that they are at their output

6 provides the minimum necessary holding voltage. The minimum necessary holding voltage is that voltage which must be present at least at the output 6 of the holding voltage unit 10, so that a current flow through the Ansteuerspulen 50 of all contactors results, which is sufficient to keep each contactor during the holding phase in the attracted state in this embodiment, the average duration T ₂ , which between the

Generation of two consecutive further control signals by the second control circuit 2 is by a factor X is smaller than the average duration ΤΊ, which is between the generation of two successive first control signals through the first control circuit 1, where 0 <X <1 applies. In other words, the first control circuit 1 operates slower than the second control circuit 2, whereby the second control circuit 2 is always capable of correcting the control signal generated by the first control circuit 1 capable.

About the interaction of minimum current selection circuit 5, the first

Actuator 1 and second control circuit 2 is thus a two-loop or cascaded control system realized within the drive circuit 30, through which the currents through the electrical connections 8 and thus by the Ansteuerspulen 50, in particular during the holding phase of the contactors, can be set to an optimum value , The first control circuit 1 closes an outer control loop, which the

Holding current through the drive coils 50 connected to the control circuit 30 used as a controlled variable, while the second control circuit 2 includes an inner control loop, which uses the holding voltage provided by the holding voltage unit 10 as a control variable. Both the first and the second control circuit 1, 2 are for a

Driving circuit 30 according to the invention, however, optional. It is also possible to realize control circuits 30 according to the invention with control circuits 20 without these components, with which, for example, a

Minimal current can be adjusted or regulated by the electrical connections 8. In this embodiment, both the first and the second control circuit 1, 2 operate continuously, so continuously perform a comparison of their input variables with their respective reference values and continuously generate and transmit control signals in response to the result of this comparison.

Claims

R. 343006 2014/060184 PCT / EP2013 / 069669 - 17 - Claims

A drive circuit (30) for at least two contactors, comprising

a first and a second terminal (11, 12) via which the

Drive circuit (30) is connectable to the poles of an energy store,

- At least a first output (15) and at least two second

Outputs (16) via which the drive circuit (30) with the

Connections of at least two drive coils for at least two

Contactors can be connected, wherein the at least two second outputs (16) via an electrical connection (8) are connected to the second terminal (12),

- A holding voltage unit (10) having an output (6) and an input (9) for receiving a control signal and which via its output (6) to the at least one first output (15)

connected and adapted to a holding voltage for setting a holding current for the drive coils at its output (6)

provide,

characterized in that

the drive circuit (30) has a control circuit (20) connected to the electrical connections (8) and the input (9) of the

Holding voltage unit (10) connected and adapted to generate one of the in the electrical connections (8) flowing currents dependent control signal and the holding voltage unit (10)

to transfer.

Second drive circuit (30) according to claim 1, wherein the holding voltage unit (10) is adapted to the amount of at its output (6).

provided holding voltage upon receipt of a control signal,

corresponding to this control signal to change. R. 343006

2014/060184 PCT / EP2013 / 069669

- 18 -

A drive circuit (30) according to any one of the preceding claims, wherein the control circuit (20) comprises a minimum current selection circuit (5) having an output and arranged to measure the actual values of the currents flowing through the electrical connections (8) and output the minimum of the measured actual values of the currents I _min across their output.

4. A drive circuit (30) according to claim 3, wherein the

Minimal current selection circuit (5) has a resistor (4) and each electrical connection (8) each have a diode (3), wherein in each case an electrical connection (8) to the cathode of a respective diode (3) is connected and wherein the anodes of the Diodes (3) with a connection of Wderstandes (4) are connected.

5. A drive circuit (30) according to claim 3, wherein the

Minimal current selection circuit (5) has a Wderstand (4) and each electrical connection (8) has a precision rectifier (7) each having two inputs and one output, wherein in each case one electrical connection (8) connected to one input of a precision rectifier (7) is while the respective other input of the respective

Precision rectifier (7) to the output of the respective

Precision rectifier (7) is traced, with the outputs of all

Precision rectifier (7) are connected to one terminal of the resistor (4).

6. A drive circuit (30) according to claim 5, wherein the precision rectifier (7) are designed as feedback operational amplifier, wherein the

Feedback branches of the operational amplifier each having a diode (3), wherein the cathodes of the diodes are respectively connected to the output of their respective operational amplifier, while the anodes of the diodes (3) to the inverting input of their respective

Operational amplifier are connected.

7. A drive circuit (30) according to any one of claims 3 to 6, wherein the

Control circuit (20) comprises a first control circuit (1) whose input is connected to the output of the minimum current selection circuit (5) and R. 343006

2014/060184 PCT / EP2013 / 069669

Whose output is connected to the input (9) of the holding voltage unit (10), wherein the first actuating circuit (1) is adapted to compare a current flowing in its input with a reference value and in dependence on the result of this comparison first

Control signal for setting a holding voltage for the

To generate holding voltage unit (10) and to transmit to the holding voltage unit (10).

Drive circuit (30) according to claim 7, wherein the reference value to the minimum necessary holding current l _Hm in the contactor to be controlled

equivalent.

A drive circuit (30) according to claim 7 or 8, wherein the first

Control signal always to the setting of a minimum necessary

Holding voltage at the output (6) of the holding clamping unit (10)

necessary control signal for the holding voltage unit (10).

A drive circuit (30) according to any one of claims 7 to 9, wherein the

Control circuit (20) comprises a second control circuit (2) which is adapted to the first of the first control circuit (1) generated

Control signal to compare with the holding voltage provided at the output (6) of the holding voltage unit (10) and another depending on the result of this comparison the first control signal

Overlay control signal.

Control circuit (30) according to claim 10, wherein the average duration T ₂ , which lies between the generation of two successive further control signals by the second control circuit (2), by a factor X is smaller than the average duration ΤΊ, which between the

Generation of two consecutive first control signals by the first control circuit (1), where 0 <X <1 applies.

Method for operating at least two contactors, comprising

- At least two drive coils for controlling at least two

Sagittarius,

- A holding voltage unit (10), which with the at least two R. 343006

2014/060184 PCT / EP2013 / 069669

- 20 -

Connected drive coils and is adapted to cause a current flow through the at least two drive coils by a holding voltage generated at its output, the method being the following

Process steps include:

Providing a pull-in current (S1) flowing through the at least two drive coils through the holding voltage unit (10);

Providing a holding current (S2) flowing through the at least two drive coils through the holding voltage unit (10);

Comparing the holder currents (S3) flowing through the at least two drive coils with one another and / or selecting the minimum of the holding currents flowing through the at least two drive coils;

- comparing the minimum of the holding currents with a reference current (S4);

Generating a first control signal (S5) for the holding voltage unit (10) for controlling the holding voltage at the output of

Holding voltage unit (10) depending on the result of the

Comparison between the minimum of the minimum through the two

Ansteuerspulen flowing holding currents with the reference current;

Comparing the first control signal (S6) with that at the output of

Holding voltage unit (10) present holding voltage;

Generating a second control signal (S7) for the holding voltage unit (10) for controlling the holding voltage at the output of

Holding voltage unit (10) depending on the result of the

Comparison between the first control signal and the voltage present at the output of the holding voltage unit (10) holding voltage.