DE102018122269A1 - Relay module - Google Patents

Abstract

The invention relates to an electromagnetic relay module 100 having a first circuit branch 119 which has a first capacitor 115 and a first relay 103 which is connected in series with the first capacitor 115, a second circuit branch 121 which has a second capacitor 117 and one in series with the second capacitor 117 has interconnected second relay 105, a switching element 125, which is arranged between the first circuit branch 119 and the second circuit branch 121 and has a first switching state and a second switching state. In the first switching state of the switching element 125, the first circuit branch 119 and the second circuit branch 121 are arranged in a parallel connection. In the second switching state of the switching element 125, the first relay 103 and the second relay 105 are arranged in a series connection. The switching element 125 is designed to switch from the first switching state to the second switching state when the relay module 100 is switched on in order to increase the overall resistance of the relay module 100.

Description

The present invention relates to a relay module, in particular an electromagnetic relay module, and an arrangement with an electromagnetic relay module.

With electromagnetic relays, there is the problem of heating due to high coil currents, which are required to pull the armature from an open position into a holding position and to close the relay. A minimal response flow is necessary to tighten the anchors. To hold the armature in the closed state, a lower holding flow is necessary in comparison to this. Since a stronger magnetic field and thus a greater magnetic flux through the excitation coil than for holding the armature in the holding position is required for tightening, solutions are desirable for the magnetic flux through the excitation coil after the armature has been tightened into the holding position and for the period in which the armature is held in the holding position, and thus reduce the power and consequently the heating of the relay for the period in which the relay is kept closed. A known solution consists in assigning pulse width modulation (PWM) to the supply voltage and in this way reducing the coil current to an advantageous value for the desired period of time. However, complex microelectronic components and correspondingly complex switching architectures are required for PWM control. The PWM can also cause electromagnetic effects on the environment, which can be undesirable.

It is an object of the present invention to provide an improved concept for a relay module.

This object is solved by the subject matter of the independent claims. Advantageous embodiments of the invention are the subject of the dependent claims, the description and the accompanying figures.

The disclosure is based on the knowledge that the above object is achieved by a relay module, which makes it possible to increase the total resistance of the relay module after the relays, in particular the relay coils of both relays of the relay module, with an unchanged supply voltage, in particular more constant and stable applied voltage to reduce the coil current and thus reduce the relay power or the electrical power and thus the heat development or the heat dissipation.

According to a first aspect, the object is achieved by an electromagnetic relay module, with a first circuit branch which has a first capacitor and a first relay connected in series with the first capacitor, a second circuit branch which has a second capacitor and a series connection with the second capacitor has a second relay, a switching element which is arranged between the first circuit branch and the second circuit branch and has a first switching state and a second switching state. In the first switching state of the switching element, the first circuit branch and the second circuit branch are arranged in a parallel connection. In the second switching state of the switching element, the first relay and the second relay are arranged in a series circuit. The switching element is designed to change from the first switching state to the second switching state when the relay module is switched on in order to increase the overall resistance of the relay module.

This has the technical advantage that a relay module can be provided, the coil power of the first relay or second relay automatically from a pull-in power, which must be provided to pull the armature from an open position to the holding position, to a lower holding power , which has to be applied in order to hold the anchor in the holding position, is reduced as soon as the first anchor and the second anchor are fully drawn into the holding position. The stop position of the relay module can be defined in such a way that the first armature of the first relay and the second armature of the second relay are closed, that is to say both relays have pulled through completely.

The design of the present relay module with two interconnected relays enables the overall resistance of the relay module to be changed, in particular increased, by converting the circuit arrangement of the two relays from a parallel connection into a series connection of the relays.

By switching the parallel connection of the first circuit branch and the second circuit branch into the series connection of the first relay and the second relay, the total resistance of the relay module, in particular a combination of the first relay and the second relay, is increased.

If the supply voltage remains unchanged, the increase in the total resistance of the series-connected first relays and second relays in turn leads to a reduction in those flowing through the first relay and the second relay Coil currents. A reduced coil current in turn leads to a reduction in the magnetic flux through the respective relays and, in turn, to a reduction in the magnetic field in the respective relay.

Due to the low resistance of the first capacitor and the second capacitor for the period in which the switching element is in the first switching state, the first and the second circuit branch are arranged in parallel and the first capacitor and the second capacitor are charged, resistances of the first capacitor and of the second capacitor for determining the total resistance for this period is negligible.

The first capacitor and the second capacitor are in turn dimensioned such that a complete charging of the first capacitor and the second capacitor corresponds to a complete tightening of the armature into the holding position. The dimensioning can depend on the operating voltage, the coil resistance, ie the internal resistance, and the inductance. In this way, it is possible to ensure that the necessary flooding is reached in order to achieve the working state of the relay module. The capacitors and components of the switching element can be designed in such a way that the switchover occurs without an additional switching pulse. The holding value is typically 50%, conservative at 60% nominal voltage.
If the coil voltage becomes zero again, the switching element switches again from the second switching state to the first switching state.

A reduction in the heat development of the relays is achieved by reducing the flow and thus reducing the respective coil power of each relay. In the case of components of small size in particular, a reduction in the development of heat is advantageous due to the low thermal capacity of the components.

In one embodiment, the relay module has a stop position in which a first armature is attracted by the first relay and in which a second armature is attracted by the second relay, and the switching element is designed to move from the first switching state to the second switching state change as soon as the relay module has taken the stop position

Tightening the anchors requires a higher flow, in particular an initial flow, than holding the anchors by the respective relay. To tighten the anchors a higher power is necessary than to hold the anchors. After the armature has been tightened, the flow through the coils of the relays can be reduced. The switching time of the switching element can therefore be selected so that switching to the series connection of the relays takes place as soon as both anchors are attracted. The current is reduced at the same voltage due to the increased total resistance and the power used is therefore also reduced.

In one embodiment, the first capacitor is designed to provide the first relay with a first charging current in the first switching state of the switching element. The second capacitor is designed to provide the second relay with a second charging current in the first switching state of the switching element. The first charging current is suitable for causing the first armature to be pulled and held, and the second charging current is suitable for causing the second armature to be drawn and held.

The charging current of the capacitors can be sufficient to switch the relays. This means that the charging current of the capacitors is sufficient to provide the initial flow for the respective relay. The capacitors can be used to set a switching time for the switching element, which switches when both armatures are attracted.

In one embodiment, the relay module can be electrically connected to a voltage source which is set up to provide a constant voltage, the first circuit branch and the second circuit branch being connectable to the voltage source.

The voltage source can be a DC voltage source that provides a constant voltage. The voltage can be, for example, 12V or 24V and thus operate both relays with a corresponding voltage value. The voltage can also have other values. The level of the voltage may depend on an application of the relay module. The voltage source can be used to reduce the current when switching over to the series circuit due to the then increased total resistance.

In one embodiment, the first capacitor provides the first charging current and the second capacitor provides the second charging current when the constant voltage is applied to the first circuit branch and to the second circuit branch.

The first capacitor and the second capacitor are charged when the constant voltage is applied. The voltage across the capacitors increases. The charging current decreases over time. However, the charging current is sufficient to switch the relays.

In one embodiment, the first switching state of the switching element comprises a high resistance of the switching element in comparison to the resistance of the switching element in the second switching state and the second switching state of the switching element comprises a low resistance of the switching element in comparison to the resistance of the switching element in the first switching state.

A high resistance can limit a current flow through the switching element to such an extent that it can be neglected. If the resistance is reduced, a current flow through the switching element is allowed. This can be seen as a switching operation.

In one embodiment, the switching element comprises a diode, the diode being set up to transition from the first switching state to the second switching state when a forward voltage of the diode is reached.

The switching element is designed here as a diode, which is operated when the two coils are connected in series in the flow direction or forward direction. The switchover from parallel to series connection can take place through the voltage difference between the first circuit branch and the second circuit branch. This is at least equal to the forward voltage of the diode. This means that a voltage below the forward voltage corresponds to a first switching state and a voltage at the forward voltage or higher corresponds to the second switching state. The forward voltage corresponds to the threshold voltage. In particular, the term forward voltage means the voltage that can be read in the diode characteristic diagram when the apparently straight-line part is extended to the x-axis.

This has the technical advantage that the switching element is easy to manufacture and the switching process runs automatically. The switching process of the switching element, which converts the parallel connection of the first circuit branch and the second circuit branch into the series connection of the first relay and the second relay, begins as soon as the voltage difference between the first circuit branch and the second circuit branch corresponds at least to the forward voltage of the diode. In addition, the current in the series circuit of the first relay and the second relay can be further reduced by the additional voltage drop across the diode and the series resistor of the switching element in the circuit branch between the first circuit branch and the second circuit branch, so that the heat losses through the first and second excitation coils can also be reduced.

If a diode is used as the switching element, the switching time is determined by the capacitance of the capacitors, i.e. the relay, with a fixed internal resistance and coil dimensions. of the first capacitor and the second capacitor. The switching time results from the voltage difference in the central branch of the circuit. At the beginning, this is equal to the total voltage applied, with zero reactance of the capacitors. By charging the capacitors, the initially negative voltage between the first circuit branch and the second circuit branch is reduced in magnitude, that is to say towards zero. If the voltage becomes positive and greater than the forward voltage of the diode, the diode switches.

In one embodiment, the switching element comprises at least one further diode and / or a series resistor in order to influence the time of the transition from the first switching state to the second switching state.

The switching time can be varied by a plurality of diodes in series and / or in combination with a series resistor to the diode between the first circuit branch and the second circuit branch. That is, the relay module can be adapted so that the switching element switches at a desired time, relative to the switching state of the relays. Due to the additional voltage drop across the diode and the resistor, the current in series connection of the coils can be further reduced. The heat losses can be reduced. The series resistor can change the diode current when the relays are switched off and the holding current, i.e. limit the operating current of the relay module in the hold state.

In one embodiment, the switching element comprises a transistor, in particular a bipolar transistor or a field effect transistor, i.e. a MOSFET.

This achieves the technical advantage that the switching element is designed as a robust component with high switching accuracy and switching reliability.

In one embodiment, the transistor is a PNP bipolar transistor, or an NPN bipolar transistor.

This achieves the technical advantage that after the switching process has been completed, a low excitation current flows in the series connection of the first and second excitation coils. A PNP transistor can reduce the current in the series connection by half compared to the parallel connection. This effect can be achieved with an NPN transistor amplified and thus the current can be further reduced.

In one embodiment, the transistor is a MOSFET transistor.

In addition, the transistor is de-energized during the switching process, so that the occurrence of power loss during the switching process on the switching element is avoided. High blocking currents can be avoided and voltage peaks can be assessed more precisely by using blocking diodes. The use of a MOSFET is more energy efficient than with another transistor, since no current flows to the control connection of the transistor. Voltage peaks on the coils when the transistor is switched off can also be avoided.

In one embodiment, the transistor is preceded by an RC element and a voltage divider, a time constant being defined via the RC element and the voltage divider.

This achieves the technical advantage that the switching time of the switching element can be matched to the point in time at which the armatures are fully pulled into the holding position by means of the time constant of the RC element. the relay module has entered the halt state. For this purpose, the RC element has a third resistor and a third capacitor. The dimensions of the third resistor and the third capacitor are matched to the first capacitor and the second capacitor. A point in time at which the stop position is reached can thus be determined over the duration of the charging of the first capacitor and the second capacitor. By coordinating the dimensioning of the RC element with regard to the ratio of the time constant of the RC element to the duration of the charging of the first capacitor and the second capacitor, it is consequently possible to coordinate the switching time of the switching element with the point in time of the complete tightening of the armature in the Stop position can be reached. This gives the technical advantage that voltage peaks at the second excitation coil are avoided.

In one embodiment, the transistor is preceded by a controller, in particular a microcontroller, which is set up to determine a switching instant of the transistor as a function of a measured current in the first circuit branch and / or the second circuit branch.

A switching point in time can also be adapted by a control, such as a microcontroller, for example in an operation by reprogramming or adjusting the control. An external voltage pulse can be given from the controller to the transistor, which leads to switching. The individual relay currents are measured, i.e. the currents through the relays.

In one embodiment, the controller is set up to provide a switching voltage for switching the switching element when the measured current falls below a predetermined limit value, in particular falls below a predetermined limit value in the first circuit branch or the second circuit branch.

The charging current of the capacitors is monitored here. If it drops to a predetermined limit after a maximum, it can be assumed that the relays have successfully pulled the respective armature. The charging current is also the current that flows through the respective coil in the first circuit branch or second circuit branch.

In one embodiment, a first blocking diode is arranged between the first relay and the switching element in order to block a current flow from the switching element to the first relay and a second blocking diode is arranged between the second relay and the switching element in order to block a current flow from the second relay to block the switching element in order to limit a switch-off current.

The blocking diodes can undesirably prevent current flow through the relays. In particular, a cut-off current can be limited here.

In one embodiment, the relay module is a safety relay module to perform a safety-relevant function and the first relay and the second relay are redundant relays.

A safety-relevant function can be a function that affects the safety of a user. For example, a user can be protected from an electric shock.

According to a second aspect, the object is achieved by an arrangement with an electromagnetic relay module of the type described above in an emergency stop switch or a protective door switch or a magnetic switch or with a light grid.

As a result, the safety of the respective component can be kept high and, in addition, the power of the relay module can be reduced as described above.

• 1 ein Ersatzschaltbild eines Relaismoduls gemäß einem Ausführungsbeispiel;
• 2 ein Ersatzschaltbild eines Relaismoduls gemäß einem weiteren Ausführungsbeispiel;
• 3 ein Ersatzschaltbild eines Relaismoduls gemäß einem weiteren Ausführungsbeispiel;
• 4 ein Ersatzschaltbild eines Relaismoduls gemäß einem weiteren Ausführungsbeispiel;
• 5 ein Ersatzschaltbild eines Relaismoduls gemäß einem weiteren Ausführungsbeispiel;
• 6 ein Ersatzschaltbild eines Relaismoduls gemäß einem weiteren Ausführungsbeispiel; und
• 7 eine schematische Darstellung einer Anordnung mit einem Relaismodul gemäß einem Ausführungsbeispiel.

Further exemplary embodiments are explained with reference to the attached figures. Show it:

• 1 an equivalent circuit diagram of a relay module according to an embodiment;
• 2nd an equivalent circuit diagram of a relay module according to another embodiment;
• 3rd an equivalent circuit diagram of a relay module according to another embodiment;
• 4th an equivalent circuit diagram of a relay module according to another embodiment;
• 5 an equivalent circuit diagram of a relay module according to another embodiment;
• 6 an equivalent circuit diagram of a relay module according to another embodiment; and
• 7 is a schematic representation of an arrangement with a relay module according to an embodiment.

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which specific embodiments are shown by way of illustration in which the invention may be carried out. It goes without saying that other embodiments can also be used and structural or logical changes can be made without departing from the concept of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. Furthermore, it goes without saying that the features of the various exemplary embodiments described here can be combined with one another, unless specifically stated otherwise.

Aspects and embodiments are described with reference to the drawings, wherein like reference characters generally refer to like elements.

1 shows an equivalent circuit diagram of a relay module 100 according to an embodiment. The electromagnetic relay module 100 includes a first relay 103 and a second relay 105 . The first relay 103 has a first internal resistance 107 and a first coil 109 on. The first coil 109 is set up to generate a first magnetic field and to attract a first armature (not shown in the figures) through the first magnetic field. The second relay 105 has a second internal resistance 111 and a second coil 113 on. The second coil 113 is set up to generate a second magnetic field and to attract a second armature (also not shown in the figures) by the second magnetic field.

If the first anchor is attracted, the first relay is located 103 in a hold state. If the second armature is attracted, the second relay is located 105 in a hold state. If the first anchor and the second anchor are both tightened at the same time, the relay module is located 100 in a hold state.

The relay module 100 has a first capacitor 115 and a second capacitor 117 on. The first capacitor 115 is in series with the first relay 103 switched. The first capacitor 115 and the first relay 103 are in a first circuit branch 119 arranged. The second capacitor 117 is in series with the second relay 105 switched. The second capacitor 117 and the second relay 105 are in a second circuit branch 121 arranged. The first circuit branch 119 and the second circuit branch 121 are arranged parallel to each other.

The relay module 100 has a voltage source 123 on. The voltage source 123 is a constant voltage source and set up to output a constant voltage. This means that the voltage is regulated to a setpoint value if there are fluctuations in the voltage provided. For example, the voltage source 123 a constant voltage of 12V ready. In a further embodiment, the voltage source 119 another constant voltage ready, for example 24V. The first voltage branch 119 and the second voltage branch 121 are electrical with the voltage source 123 connected.

By applying the constant voltage through the voltage source 123 becomes charging the first capacitor 115 and the second capacitor 117 causes. By charging the first capacitor 115 a first charging current flows through the first relay 103 . By charging the second capacitor 115 a second charging current flows through the second relay 103 .

The first capacitor 115 is dimensioned such that the first charging current is suitable for causing magnetic flux through the first coil and thus a corresponding magnetic field which is suitable for the first armature of the first relay 103 fully tighten and so the first relay 103 to put in the stop position. The second capacitor 115 is dimensioned such that the second charging current is suitable for causing a magnetic flooding of the second coil and thus a corresponding magnetic field which is suitable for the second armature of the second relay 103 fully tighten and so the second relay 103 to put in the stop position. Both capacitors 115 , 117 are dimensioned so that the charging current is sufficient for the coils used 109 , 113 a To achieve initial flooding, each of which generates a magnetic field to attract the corresponding anchor.

The relay module 100 has a switching element 125 on. The switching element 125 is between the first circuit branch 119 and the second circuit branch 121 arranged such that the switching element 125 between the first relay 103 and the first capacitor 115 and between the second capacitor 119 and the second relay 105 is arranged. The switching element 125 has a first switching state and a second switching state.

In the first switching state of the switching element 125 is the switching element 125 open or high impedance to a current flow from the first relay 103 to the second relay 105 through the switching element 125 to prevent. Preventing this can be understood to mean that the current flow is interrupted or limited to such an extent that it is used in the normal application of the relay module 100 is negligible. In the second switching state of the switching element 125 is the first circuit branch 119 electrically with the second circuit branch 121 through the switching element 125 connected so that an electrical current through the switching element 125 can flow. The switching element is here 125 closed or low-resistance.

With switching of the switching element 125 in the second circuit state, the parallel connection of the first and second circuit branches 101 , 102 in a series connection of the first and second relays 103 , 105 switched. That is, through the switching element 125 are in the second switching state of the switching element 125 the first relay 103 and the second relay 105 electrically connected in series.
The switching element 125 is set up to switch from the first switching state to the second switching state when the relay module 100 reached the holding state, that is, as soon as the first anchor and the second anchor are tightened.

The first capacitor 115 and the second capacitor 117 are at the switching time of the switching element 125 high impedance and not part of the series connection of the first relay 103 and the second relay 105 . They thus ensure that there is a primary current path along the series connection of the first relay 103 and the second relay 105 runs.

With switching of the parallel connection of the first and second circuit branches 101 , 102 for connecting the first relay in series 103 and the second relay 105 is the total resistance of the first relay 103 and the second relay 105 elevated. This has a reduction in the coil currents at a constant voltage, which is ensured by the voltage source, and an associated reduction in the magnetic flux and the magnetic fields of the first relay 103 and the second relay 105 result, thereby reducing the power loss of the relay module 100 can be reduced.

In 2nd is an equivalent circuit diagram of a relay module 200 shown according to a further embodiment. Here, the switching element comprises 125 a diode 201 and one of the diode 201 series-connected series resistor 203 . By means of the diode 201 and the series-connected series resistor 203 is the time of switching the switching element 125 , in which the parallel connection of the first circuit branch 119 and the second circuit branch 121 in the series connection of the first relay 103 and the second relay 105 is transferred to the voltage difference between the first circuit branch 119 and the second circuit branch 121 connectable. The switching element 125 switches as soon as the voltage difference between the first circuit branch 119 and the second circuit branch 121 the forward voltage of the diode 201 corresponds.

In a further exemplary embodiment (not shown in the figures), the switching element comprises 125 a plurality of diodes connected in series. In a further exemplary embodiment, the switching element comprises 125 additionally a plurality of series resistors connected in series. As a result, the time of the switching operation of the switching element 125 compared to the circuit with only one diode 201 and a series resistor 203 to be changed.

In 3rd is an equivalent circuit diagram of a relay module 300 shown according to a further embodiment. Here, the switching element comprises 125 a transistor 301 . In the exemplary embodiment shown is the transistor 301 a PNP bipolar transistor. In a further embodiment, it is a different transistor, in particular an NPN bipolar transistor.

The transistor 301 is via the basic connection with a voltage divider 303 having a first resistance 305 and a second resistor 307 includes. The transistor 301 is also via the basic connection with an RC element 309 electrically connected which is a third resistor 311 and a third capacitor 313 includes, connected. About the dimensioning of the RC link 309 and the first resistance 305 and the second resistance 307 of the voltage divider 303 is the switching time of the transistor 301 can be coordinated with the time when the first armature and the second armature are fully tightened, ie the switching time of the switching element 125 is about that Reaching the hold state of the relay module 100 connectable, in particular coupled.

In in 3rd shown embodiment have the first circuit branch 119 additionally a first blocking diode 315 and the second circuit branch 121 a second blocking diode 317 on. The first blocking diode 315 and the second blocking diode 317 are like that between the first relay 103 and the first capacitor 115 or the second capacitor 117 and the second relay 105 arranged that the first blocking diode 315 and the second blocking diode 317 Parts of the series connection with the first relay 104 and the second relay 105 are when the transistor is in the conductive state and the switching element 103 is thus in the second switching state. In a further exemplary embodiment, one or both blocking diodes can be used 115 , 117 omitted.

In 4th is an equivalent circuit diagram of a relay module 400 shown according to a further embodiment. Here is the switching element 125 , how to 3rd described the transistor 301 . The first circuit branch also has 119 the first blocking diode 315 and the second circuit branch 121 the second blocking diode 317 on.

However, instead of the voltage divider 303 and the RC link 309 to control the switching time of the transistor 301 a controller 401 , in particular a microcontroller is provided which is connected to the base connection of the transistor 301 is connected and is set up, via an output of the control, a switching signal to the base connection of the transistor 301 to send. This allows the switching element 125 , ie the transistor 301 , are transferred from the first switching state to the second switching state.

To determine the time for switching the switching element 125 comprises the circuit according to the in 4th Embodiment shown a current measuring device 403 . The current measuring device 403 includes a current measurement resistor, not shown. In a further exemplary embodiment, the current is measured contactlessly using a current clamp.

If the measured current reaches a limit value stored in the control, the control generates 401 a control signal and sends the control signal via an output of the controller 401 to the transistor 301 to the transistor 301 to switch and the switching element 125 to move from the first switching state to the second switching state.

5 shows an equivalent circuit diagram of a relay module 500 according to a further embodiment. The relay module 500 according to the embodiment of 5 corresponds to the relay module 300 of the embodiment of 3rd . However, the transistor 301 a field effect transistor, in particular a metal oxide semiconductor field effect transistor, or MOSFET for short.

The voltage divider 303 and the RC link 309 are connected to the gate connection of the MOSFET at the switching time of the switching element 125 at the transition of the relay module 100 to adapt to the hold state.

6 shows an equivalent circuit diagram of a relay module 600 according to a further embodiment. The relay module 600 according to the embodiment of 6 corresponds to the relay module 400 of the embodiment of 4th . However, the transistor 301 a field effect transistor, in particular a metal oxide semiconductor field effect transistor, or MOSFET for short.

The control 401 is connected to the gate connection of the MOSFET at the switching time of the switching element 125 at the transition of the relay module 100 to adapt to the hold state.

7 shows an arrangement 700 . The order 700 includes the relay module 100 and an emergency stop switch 701 . In another embodiment, one of the relay modules 200 , 300 , 400 , 500 or 600 installed. In a further exemplary embodiment, the arrangement comprises 700 the relay module 100 and a safety gate switch or a magnetic switch or a light curtain.

The relay module 100 is arranged so that by the relay module 100 a safety-relevant function of the arrangement 700 can be fulfilled. In the embodiment shown, the emergency stop switch 701 the relay module 100 actuated to a circuit 703 to interrupt. The circuit 703 is in 7 only partially shown for reasons of clarity. In particular, the circuit 703 include other components in parts not shown or be connected to machines. The first relay is interrupted 103 and the second relay 105 the circuit 703 redundant. This means that the circuit is also interrupted 703 guaranteed, one of the two relays 103 , 105 malfunction, such as a jamming anchor.

Reference list

100, 200, 300

Relay module

400, 500, 600

Relay module

103

first relay

105

second relay

107

first internal resistance

109

first coil

111

second internal resistance

113

second coil

115

first capacitor

117

second capacitor

119

first circuit branch

121

second circuit branch

123

Voltage source

125

Switching element

201

diode

203

Series resistor

301

transistor

303

Voltage divider

305

first resistance

307

second resistance

309

RC link

311

third resistance

313

third capacitor

315

first blocking diode

317

second blocking diode

401

control

403

Current measuring device

700

arrangement

701

Emergency stop switch

703

Circuit

Claims (15)

Electromagnetic relay module (100, 200, 300, 400, 500, 600), with: a first circuit branch (119) which has a first capacitor (115) and a first relay (103) connected in series with the first capacitor (115), a second circuit branch (121) which has a second capacitor (117) and a second relay (105) connected in series with the second capacitor (117), a switching element (125) which is arranged between the first circuit branch (119) and the second circuit branch (121) and has a first switching state and a second switching state, wherein in the first switching state of the switching element (125) the first circuit branch (119) and the second circuit branch (121) are arranged in a parallel circuit, and wherein in the second switching state of the switching element (125) the first relay (103) and the second relay (105 ) are arranged in a series circuit, and wherein the switching element (125) is designed to switch from the first switching state to the second switching state in the switching-on process of the relay module (100, 200, 300, 400, 500, 600) in order to reduce the total resistance of the relay module (100, 200, 300, 400 , 500, 600) increase. Electromagnetic relay module (100, 200, 300, 400, 500, 600) after Claim 1 , wherein the relay module (100, 200, 300, 400, 500, 600) has a stop position in which a first armature is attracted by the first relay (103) and in which a second armature is attracted by the second relay (105) , and wherein the switching element (125) is designed to change from the first switching state to the second switching state as soon as the relay module (100, 200, 300, 400, 500, 600) has assumed the stop position. Electromagnetic relay module (100, 200, 300, 400, 500, 600) after Claim 2 , wherein the first capacitor (115) is designed to provide the first relay (103) with a first charging current in the first switching state of the switching element (125) and the second capacitor (117) is designed to provide the second relay in the first switching state of the switching element (125) (105) to provide a second charging current, the first charging current being suitable for causing the first armature to be pulled and held, and the second charging current being suitable for causing the second armature to be pulled and held. Electromagnetic relay module (100, 200, 300, 400, 500, 600) according to one of the preceding claims, wherein the relay module (100, 200, 300, 400, 500, 600) can be connected to a voltage source (123) which is set up to provide a constant voltage, the first circuit branch (119) and the second circuit branch (121) being connectable to the voltage source (123). Electromagnetic relay module (100, 200, 300, 400, 500, 600) according to the Claims 3 and 4th , wherein the first capacitor (115) provides the first charging current and the second capacitor (117) provides the second charging current when the constant voltage is applied to the first circuit branch (119) and to the second circuit branch (121). Electromagnetic relay module (100, 200, 300, 400, 500, 600) according to one of the preceding claims, wherein the first switching state of the switching element (125) has a higher resistance of the switching element (125) compared to the resistance of the switching element (125) in the second Switching state includes and where the second Switching state of the switching element (125) comprises a lower resistance of the switching element (125) compared to the resistance of the switching element (125) in the first switching state. Electromagnetic relay module (100, 200, 300, 400, 500, 600) after Claim 6 , wherein the switching element (125) comprises a diode (201), the diode (201) being set up to transition from the first switching state to the second switching state when a forward voltage of the diode (201) is reached. Electromagnetic relay module (100, 200, 300, 400, 500, 600) according to one of the Claims 6 or 7 , wherein the switching element (125) comprises at least one further diode and / or a series resistor (203). Electromagnetic relay module (100, 200, 300, 400, 500, 600) according to one of the Claims 1 to 6 , wherein the switching element (125) comprises a transistor (301), in particular a bipolar transistor or a MOSFET. Electromagnetic relay module (100, 200, 300, 400, 500, 600) after Claim 9 The transistor (301) is preceded by an RC element (309) and a voltage divider (303) by which a time constant is defined. Electromagnetic relay module (100, 200, 300, 400, 500, 600) after Claim 9 The transistor (301) is preceded by a control (401), in particular a microcontroller, which is set up as a function of a measured current in the first circuit branch (119) or the second circuit branch (121), a switching instant of the transistor (301) to determine. Electromagnetic relay module (100, 200, 300, 400, 500, 600) after Claim 11 , wherein the controller (401) is set up to provide a switching voltage for switching the switching element (125) when the measured current falls below a predetermined limit value. Electromagnetic relay module (100, 200, 300, 400, 500, 600) according to one of the Claims 9 to 12th , wherein a first blocking diode (315) is arranged between the first relay (103) and the switching element (125) to block a current flow from the switching element (125) to the first relay (103) and a second blocking diode (317) between the second relay (105) and the switching element (125) is arranged to block a current flow from the second relay (105) to the switching element (125). Electromagnetic relay module (100, 200, 300, 400, 500, 600) according to one of the preceding claims, wherein the relay module (100, 200, 300, 400, 500, 600) is a safety relay module to perform a safety-relevant function and wherein the first relay (103) and the second relay (105) are redundant relays. Arrangement with an electromagnetic relay module (100, 200, 300, 400, 500, 600) according to one of the Claims 1 to 14 in an emergency stop switch (701) or a protective door switch or a magnetic switch or with a light grid.

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