WO1982002115A1

WO1982002115A1 - Electronic device for the energization of an electromagnetic element

Info

Publication number: WO1982002115A1
Application number: PCT/DE1981/000221
Authority: WO
Inventors: Boveri & Cie Brown
Original assignee: Petschenka Edwin; Beulen Winfried; Rothmeier Erich
Priority date: 1980-12-17
Filing date: 1981-12-16
Publication date: 1982-06-24
Also published as: NL8120487A; DE3152626C1; SE439400B; CH659345A5; EP0067185A1; EP0067185B1; ATA908981A; GB2105132A; SE8204712D0; SE8204712L; DE3152626D2; DE3047488A1; AT384119B

Abstract

Electronic device for the energization of an electromagnetic element, particularly a troke-coil or a coil of an electromagnetic switching apparatus having a magnetic circuit with a coil, a yoke and an armature. A comparator (5) receives a predetermined current order value U(Isoll?) and an actual measured cerment value U(Iist?). When the actual value goes down below the order value, the comparator (5) actuates, through a monostable flip flop element (6), a switching transistor (1) supplied by a supply voltage Uv?, arranged in the main current circuit of the electromagnetic element (2). After the constant conduction duration tein? has elapsed, it blocks the transistor (1). With a variable conduction duration tein? of the switching transistor (1), there results a variation of the current order value, function of the set conduction duration. In order to obtain a reliable operating mode of an electromagnetic switching apparatus comprising a coil, there is established a high actuation current order value and, after operation of the switching apparatus, a reduced maintaining current order value. For the operation of different switching states of the switching apparatus, the coil inductivity is taken into account.

Description

A M RT AG ABOUT INTERNATIONAL COOPERATION IN THE FIELD OF PATENTING (PCT)

(51) International Patent Classification 3 (11) International publication number. WO 82 /

H01H 47/32; H01F 7/18 AI H03K 17/64 (43) International

RELEASE DATE June 24, 1982 (2

(21) International file number: PCT / DE81 / 00221 (74) Lawyer: KEMPE, Wolfgang; Postfach 12 73, Mannheim 1 (DE).

(22) International filing date:

December 16, 1981 (12/16/81)

(81) Destination countries: AT, BE (European CH, DE, FR (European patent), GB, JP,

(31) Priority reference number: P 3047488.5 SE, US.

(32) Priority date: December 17th, 1980 (December 17th, 1980)

Released

(33) Country of priority: DE With international search report. Before the deadline for changes in claims expires. Publication is repeated

(71) Applicants (for all destination countries except US): arrival.

BROWN, BOVERI & CIE [DE / DE]; Aktiengesellschaft, Kallstadter Strasse 1, D-6800 Mannheim 31 (DE).

(72) inventor; and

(75) Inventor / applicant (only for US): PETSCHENKA, Edwin [DE / DE]; Am Sonnenhang 23, D-7524 Tiefenbach (DE). BEULEN, Winfried [DE / DE]; Kirchenbergweg 6, D-6900 Heidelberg (DE). ROTHMEIER, Erich [DE / DE]; Gartenstrasse 66, D-6920 Sinsheim (DE).

(54) Title: ELECTRONIC DEVICE FORTHE ENERGIZATION OF AN ELECTROMAGNETIC ELE MENT

(54) Description: ELECTRONIC CIRCUIT ARRANGEMENT FOR CONTROLLING AN ELE MAGNETIC COMPONENT

(57) Abstract

Electronic device for the energization of an electroma- _tι _ Λ_ gnetic element, particularly a troke-coil or a coil of an electro- r-§- magnetic switching apparatus having a magnetic cireuit with ay ^■ coil, a yoke and an armature. A comparator (5) reeeives aprede- j termined current order value U (Isoll2) and an actual measured current value UO-st). hen the actua] value goes down below the order value, the comparator (5) actuates, through a mono- stable flip flop element (6), a switching transistor (1) supplied by a supply voltage Uv, arranged in the main current cireuit of the electromagnetic element (2). After the constant conduction duration in πas elapsed, it blocks the transistor (1). With a variable conduetion duration tein of the switching transistor (1), there results a variation of the current order value, funetion of the set conduetion duration. In order to obtain a reliable operating mode of an electromagnetic switching apparatus comprising a coil, there is established a high actuation current order value and, after Operation of the switching apparatus, a reduced maintaining current order value. For the Operation of differentt ^ J switching states of the switching apparatus, the coil induetivity is taken into aecount. together

Electronic circuit arrangement for an electromagnetic component (2), in particular a choke or a coil of an electromagnetic switching device having a magnetic circuit with a coil, yoke and armature. A predetermined current setpoint U (I _soI ) and a measured current _actual value U (I _ist ) are fed to a comparator (5). If the current actual value falls below the current setpoint, the comparator (5) controls one in the main circuit of the electromagnetic component via a monostable trigger element (6) (2) lying through, with supply voltage U _v switching transistor (1) through. After _a lapse of the constant-time t disables the transistor (1). With a variable switch-on time t _{eιn of} the switching transistor (1), a differentiated current setpoint is given as a function of the determined switch-on time. For the safe operation of an electromagnetic switchgear with a coil, a high pull-in current setpoint and after the switchgear has been tightened, a reduced holding current setpoint is specified. The inductance of the coil is used to evaluate the different switching state of the switching device.

ONLY FOR INFORMATION

Code used to identify PCT contracting states on the headers of the international writings

Publish registrations according to the PCT.

AX Austria KP Democratic People's Republic of Korea

AU Australia u Liechtenstein

1 »Brazil U Luxembourg

CF Central African Republic MC Monaco

CG Congo MG Madagascar

CH Switzerland MW Malawi

CM Cameroon NL Netherlands

DE Germany, Federal Republic of NO Norway

DK Denmark RO umania

FI Finland SE Sweden

FS France SN Senegal

GA Gabon SU Soviet Union

GB United Kingdom TD Chad

HU Hungary TG Togo

JP Japan US United States

Electronic circuit arrangement for controlling an electromagnetic component.

Technical field:

The invention relates to an electronic circuit arrangement for controlling an electromagnetic component, in particular a choke or a coil of an electromagnetic switching device having a magnetic circuit with a coil, yoke and armature.

Underlying state of the art:

Electromagnetic components, such as switching relays and contactors, are generally known in numerous design variants. Such switching devices consist of a yoke with one or more coils and an armature which is magnetically attracted by the yoke after application of a control voltage to the coil and thereby actuates switching contacts.

A disadvantage of the known electromagnetic switching device can be seen in the large variety of types, due to the different excitation voltages with the same switching capacity, the large construction volume and the large necessary control output. The known electromagnetic switching devices can generally be used either only for direct current or only for alternating current. In addition, a coil can only be used for a narrow excitation voltage range to ensure that the armature is securely tightened.

Disclosure of the Invention:

The invention has for its object to provide an electronic circuit arrangement for controlling an electromagnetic component, which enables universal use of the electromagnetic component, i.e. allows operation for direct and alternating current, which is largely independent of the level of the voltage and also reduces the size and power consumption of the component.

According to a first variant, this object is achieved in that a comparator has a predetermined current setpoint and a measured current actual value corresponding to the current in the electromagnetic component on the input side, and the comparator on the output side, depending on the control deviation between the current setpoint and current actual value, is in the main circuit of the electromagnetic component, with the supply voltage for controlling the electromagnetic component switch, in particular a switching transistor.

According to a second variant, this object is achieved according to the invention in that the control deviation between an induction setpoint and an actual induction value of the magnetic circuit of the electromagnetic component is supplied and that the two-point controller controls a switching amplifier connected to the electromagnetic component in such a way that the induction value moves within predefined limit values, the switching amplifier being acted upon on the input side by the supply voltage for actuating the electromagnetic component.

The advantages that can be achieved with the invention are, in particular, that the control suppresses the influence of the supply voltage on the coil current, so that a large degree of independence from the supply voltage is achieved. In the theoretical case, the lower voltage limit for the supply voltage is only the minimum voltage of the electronics supply, e.g. approx. 5V DC voltage and as the upper voltage limit the maximum voltage capacity of the electronic components, e.g. approx. 1000V DC voltage. This can drastically reduce the variety of types caused by the various supply voltages (excitation voltages, control voltages) in electromagnetic components, in particular switching devices. For the entire voltage range between 5V and 1000V, for example, the same switching device can be used, whereby a safe tightening of the armature is always guaranteed.

No inductive switching voltage occurs at the connections for the supply voltage. The power consumption in the switched-on state of the switching device in the case of a circuit-operated switching device with the electronic circuit arrangement according to the invention is significantly reduced.

Advantageous embodiments of the invention are in the Subclaims marked.

Further advantages are evident from the description below.

Brief description of the drawings:

Embodiments of the invention are explained below with reference to the drawings.

Show it:

1 and 2 electronic circuit arrangements for

Control of an electromagnetic component, the magnetic flux in the component being regulated to a constant value, FIGS. 3 and 4 for electronic circuit arrangements

Activation of an electromagnetic component, with a switchover being made between an increased starting current and a lower holding current, FIGS. 5A, B, C, D show the time profiles of the currents and voltages of interest for the arrangement according to FIG. 1, and FIG. 6 shows an electronic circuit arrangement for activating a 7A, B, C the temporal profiles of the currents and voltages of interest for the arrangement according to FIG. 6, FIG. 8 a detailed embodiment for

6, FIG. 9 shows an electronic circuit arrangement for controlling an electromagnetic component with a two-point controller and induction value acquisition,

10A, B, C the temporal profiles of the currents and voltages of interest for the arrangement according to FIG. 9, FIG. 11 a Hall probe used for induction value detection,

Fig. 12 shows a detailed embodiment for

9 arrangement,

13 shows a basic illustration of the arrangement according to FIG. 12,

14 shows a mechanical design of an arrangement according to FIGS. 9, 11, 12, 13.

Best way to carry out the invention:

1 shows a first embodiment of an electronic circuit arrangement for controlling an electromagnetic component. A switching transistor 1 (pnp type) is connected via its emitter to the input terminal E1 of the circuit arrangement. The supply voltage + U _{v is applied} to the input terminal E1 as the control voltage. The supply voltage + U _v can be switched via an external switch S. The collector of the switching transistor 1 is connected to an electromagnetic component 2 (eg coil of a switching relay, choke, etc.). The electromagnetic component 2 has an ohmic resistance R ₁ and an inductance L.

The electromagnetic component 2 is connected via its further terminal to a controllable resistor 3 (for example a field effect transistor). The ohmic resistance of the controllable resistor 3 is denoted by R _w . The further connection of the controllable resistor 3 is connected via a measuring resistor R ₂ (shunt) to the input terminal E2 and thus to ground. The collector of the Switching transistor 1 is also connected to the cathode of a free-wheeling diode 4, the anode of which is connected to ground.

The two connection points of the controllable resistor 3 are bridged by means of a voltage divider consisting of the high-resistance resistors R ₃ and R ₄ . The resistor R ₃ is connected to the electromagnetic component 2 and the resistor R ₄ to the measuring resistor R ₂ . The resistance ratio R ₃ / R ₄ corresponds to the ratio R ₁ / R ₂ . The voltage drop across R ₂ + R ₄ is therefore proportional to the voltage drop across the entire ohmic resistance R ₁ + R ₂ + R _w for each resistance value R _{w of} the controllable resistor 3. At the common connection point of the resistors R ₃ , R ₄ , the actual current value U (I _ist ) is tapped as a voltage value and fed to the first input of a comparator 5.

A current setpoint U (I _{soll 2} ) is applied to the second input of the comparator 5. The comparator 5 is connected on the output side to a monostable flip-flop 6 and controls the flip-flop 6 whenever the current actual value U (I _ist ) is less than or equal to the current setpoint U (I _{soll 2} ). The monostable multivibrator 6, on its side, controls the switching transistor 1 on its output side. The duty cycle of _a t of the monostable multivibrator 6 is constant.

The actual current value U (I _ist ) is also the first. Input of a subtractor 7 supplied. The second

The current setpoint U (I _{soll 2} ) is applied to the input of the subtractor 7. The subtractor 7 forms the differential voltage U (I _ist ) - U (I _{soll 2} ) = U (i), that is to say the AC component of the current U (I _ist ) flowing through the electromagnetic component 2. The output voltage U (i) of the subtractor 7 becomes a smoothing element 8 (e.g. PT1 link) fed. The smoothing element 8 forms the average

of the AC component U (i) and feeds this value to the first input of a subtractor 9. A current setpoint U (Isoll 1) is applied to the second input of the subtractor 9. The subtractor 9 forms the difference value

U (I _{should 2} ) = U (I _{should 1} ) -

and passes this current setpoint U (I _{soll 2} ) to the second inputs of the comparator 5 and the subtractor 7.

A voltage divider 10 consisting of two resistors R ₅ , R ₆ is supplied with the supply voltage + U _v by its connection formed by resistor R ₅ and is connected to ground by its connection formed by resistor R ₆ . The resistance ratio R5 / R6 corresponds to the ratio R ₁ / R ₂ . At the common connection point of the two resistors R ₅ / R ₆ , the voltage value R ₂ / (R ₁ ) + R ₂ ) · U _{v can} thus be tapped and this voltage value is fed to the first input of a subtractor 11.

The second input of the subtractor 11 is in turn connected to the current setpoint U (I _{soll 2} ). The subtractor 11 forms the difference value U _D = R ₂ / (R ₁ + R ₂ ) · U _v - U (I _soll 2) and specifies the difference voltage U _D as a setpoint to a PI controller 12.

The output value u (i) of the subtractor 7 is fed to a peak value meter 13. The peak value meter 13 forms the peak value

of the AC component U (i) and feeds this peak value to the PI controller 12 as the actual value. On the output side, the PI controller 12 controls the controllable resistor 3 via its control input and in this way changes the ohmic resistance value R _{w of} the resistor 3 as a function of the apex worth it

and the differential voltage U _D.

For the following description of the functioning of the electronic circuit arrangement according to FIG. 1, reference is made to FIGS. 5A, B, C, D. 5A shows the time profile of the actual current value U (I _is ). The current setpoint U (I _{soll 2} ) is entered as a constant value. The Einsσhaltdauer the monostable multivibrator 6 and the switching transistor 1 is denoted by t _a. 5B shows the time profile of the alternating current component U (i) = U (I _ist ) - U (I _{soll 2.} ) of the actual current value. The peak value of the AC component is

. The mean value of the AC component is designated U (T). 5C shows the time profile of the current I ₁ flowing through the switching transistor 1. 5D is the time profile of the current flowing through the freewheeling diode 4 during the blocking times of the switching transistor 1

I ₄ shown. The currents I ₁ and I ₄ and the total current flowing through the electromagnetic component 2

I ₁ + I ₄ are entered in Figures 1, 2, 3, 4, respectively.

In the circuit of Fig. 1, the switching transistor 1 is turned on alternately by means of the monostable multivibrator 6 and locked, wherein the duty cycle t _on of the switching transistor is always constant. The blocking period of transistor 1 is not constant. When the switching transistor 1 is turned on, there is a current flow I ₁ from the input terminal via the emitter-collector path of the switching transistor 1, the electromagnetic component 2, the controllable resistor 3 and the measuring resistor R ₂ . When the switching transistor 1 is blocked, a current flow I ₄ results via the freewheeling diode 4, the electromagnetic component 2, the controllable resistor 3 and the measuring resistor R ₂ . A total current I ₁ + I ₄ flows via the electromagnetic component 2. The actual current value U (I _ist ) corresponds to this total current I ₁ + I ₄ .

The following relationship exists between the magnetic flux ∅ in the electromagnetic component 2 and its inductance L: ∅ = L · I / n.

Here, n is the number of turns in the electromagnetic component 2 (coil, choke), which represents a constant factor. With the help of the electronic circuit arrangement according to FIG. 1, the current I ₁ + I ₄ through the component 2 is controlled by measuring the inductance L such that the magnetic flux ∅ remains constant regardless of the supply voltage U _v . The following applies to the current actual value U (I _ist ) which simulates the sum current I ₁ + I ₄ at the time when the switching transistor 1 is switched on: U (I _ist ) = U (I _{soll 2} ) + U _D / R _tot (1 - e ^{-t / t} ), ie the AC component U (i) = U _D / R _tot (1 - e ^{-t / t} ) for the switch-on process, with R _tot = R ₁ + R ₂ + R _w the total resistance of the circuit and with tr the time constant t = L / R _{tot are} designated.

For the current increase at the time the switching transistor 1 is switched on, the differential voltage U _{D is} significant, which corresponds to the voltage Uv minus the ohmic voltage drop across the resistors R ₁ , R _w , R ₂ at the moment when the switch 1 is switched on. The influence of the differential voltage Un can be largely eliminated by the peak value

of the AC component U (i) is corrected to a value that is proportional to the differential voltage U _D. This is done by the PI controller 12, which changes the ohmic resistance R _{w of} the controllable resistor 3 and thus t accordingly. Due to the regulation of the peak value

proportional to the differential voltage U _D , the rise time of the current U (i) depends only on the time constant f = L / R _geg . Since a changing inductance L is compensated for in terms of circuitry by changing the total resistance R _ges via R _w , the time constant t remains constant. The inductance L changes depending on whether the armature of the component 2 designed as a switching device is attracted or not. The inductance also changes when the

Magnetic material of yoke and armature of component 2.

If the current setpoint U (I _{soll 2} ) is changed inversely proportional to the total resistance R _ges , then t ~ L · U (I _{soll 2} ) applies and thus t ~ ∅. About the relationship

_D and a predefined tent constant t can be used to determine the length of time that the current I ₁ requires for a predefined magnetic flux ∅ to rise to the maximum value. This time period corresponds to the duration t _a of the switching transistor 1 and is defined by the monostable multivibrator 6 and kept constant. The electronic circuit arrangement regulates the time constant t via the PI controller 12 and the controllable resistor 3 (keeps t constant) such that the current I ₁ through the electromagnetic component 2 for a given switch-on time t _{one of} the switching transistor 1 is determined by the differential voltage Up Maximum value reached.

In order to regulate the flow ∅ to a mean value, the predetermined setpoint U (I _{soll 1} ) must be around the mean value

of the AC component U (i) can be reduced. The AC component U (i) is formed by the subtractor 7. This draws from the current actual value U (I _is) the Strorasollwert U (I _{should 2).} The average value of the AC component U (i) is given by the smoothing element 8 formed and given to the subtractor 9, the current setpoint U (I _{soll 1} ) is also present on the input side. The current setpoint U (I _{soll 2} ) on the output side of the subtractor 9 is around the mean value

of U (i) is less than the current setpoint U (I target ₁ ). If the flow ∅ is to be regulated to a minimum value and not to an average value, the current setpoint value U (I _{setpoint 1} ) is not corrected by the average value

, ie the current setpoint U (I _{soll 1} ) is fed directly to the comparator 5.

The peak value U

of the current U (i), which is reached after the switching transistor 1 is switched on, depends on the time constant t and the differential voltage U _D. With a constant time constant t and constant duty cycle tein, the current U (i) reaches a peak value ü

, which is always proportional to the differential voltage Un. This differential voltage U _D is given to the PI controller 12 as a setpoint. The peak value becomes the actual value

of the AC component U (i) given to the controller 12. The one for forming the peak value

serving peak value indicator 13 gives the peak value

in the form of a DC voltage to the controller 12.

To determine the differential voltage U _D , the voltage which is present across the resistors R ₁ + R ₂ + R ₃ + R ₄ at the moment when the transistor 1 is switched on is subtracted from the supply voltage Uv. Since the voltage across the resistors R ₁ + R ₂ + R ₃ + R ₄ at the time the transistor 1 is switched on is proportional to U (I _{soll 2} ), this value U (I _{soll 2} ) is obtained with the aid of the subtractor 11 evaluated (adapted) supply voltage R ₂ / (R ₁ + R ₂ ) · U _v subtracted. The voltage divider 10 is used to adapt the supply voltage U _v to the value U (I _{soll 2} ). In the steady state, the voltage drop across the measuring resistor R ₂ offers the possibility of making a statement about the current state of the electromagnetic component 2 and of evaluating it electronically (inductance evaluation). When using a switching relay as an electromagnetic component 2, the switching state of the relay can be determined in this way, for example, ie whether the armature is attracted or not.

2 shows a second embodiment of an electronic circuit arrangement for controlling an electromagnetic component. The switching transistor 1 is in turn connected to the supply voltage U _v via its emitter and is connected via its collector to the electromagnetic component 2 and to the free-wheeling diode 4. On the other hand, the electromagnetic component 2 is connected directly to the measuring resistor R ₂ .

The actual current value U (I _ist ) is tapped at the common connection point between the electromagnetic component 2 and the measuring resistor R ₂ as a voltage value and fed to the first input of the comparator 5. The second input of the comparator 5 is in turn supplied with the current setpoint U (I _{soll 2} ). The comparator 5 compares the current setpoint and the current actual value and directly controls the switching transistor 1 on the output side whenever the current actual value U (I _ist ) falls below the current setpoint U (I _soll 2).

A voltage divider 10 with resistors R ₅ , R _{6 is again} provided, which is connected between supply voltage + U _v and ground. At the common connection point of the resistors R ₅ , R ₆ , the voltage value R ₂ / (R ₁ + R ₂ ) · U _v tapped and fed to the first input of a subtractor 14. The second input of the subtractor 14 is supplied with the current setpoint U (I _soll 1). The subtractor 14 forms the differential voltage U _D = R ₂ / (R ₁ + R ₂ ) · U _v - U (I _soll 1) and passes this value to the first input of a controllable adder 15. The differential voltage U _D corresponds to the voltage U _v minus the ohmic voltage drop across the resistors R ₁ , R ₂ when switch 1 is switched on.

The current input value U (I _{soll 1} ) is applied to the second input of the controllable adder 15. The control input of the adder 15 is connected to the output of the comparator 5. The controllable adder 15 always outputs a current setpoint U (I _{soll 2} ) - U (I _{soll 1} ) on the output side when the switching transistor 1 blocks, ie when U (l _is ) is greater than U (I _{soll 2} ) and gives always a current setpoint

U (I _soll2 ) = U (I _{soll 1} ) + U _{D on the} output side when the switching transistor 1 conducts, ie when U (I _ist ) is smaller than U (I _{soll 2} ).

The output signal of the comparator 5 is fed to the input of a time recording device 16. The time detector 16 determines the variable duty cycle t _a of the switching transistor 1 and this value to a setpoint value generator 17 to. The setpoint generator 17 outputs the current setpoint U (I _{soll 1} ) on the output side as a function of the switch-on duration tein of the switching transistor 1. As already mentioned, this current setpoint U (I _{soll 1} ) is fed to the subtractor 14 and the controllable adder 15.

If necessary, a smoothing element (eg PT ₁ link) can be switched for averaging.

1, the on-time t _{e in of} the switching transistor 1 is kept constant and the time constant t is regulated by changing the total resistance Rges by the peak value

to keep the Wechselstrσraanteils proportional to Vn, changes in the electronic Schaltungsanordπung of FIG. 2, the time constant t as a function of L and the duty cycle t _a of the switching transistor 1 will be tracked.

The target value generator 17 is thereby a high Strorasollwert U (I _soll 1) from when the duty cycle t _on of the switching transistor 1 is small and it is a small current setpoint Udsoll 1) when the duty ratio f _a Sross is, the target value generator 17 that is changed continuously or in individual steps, the current setpoint U (I _soll 1) as a function of the on-time determined via the time recording device 18.

The current setpoint Udson 1) the comparator set 5 via the controllable adder 15 during the nonconducting periods of the switching transistor 1 directly, that is valid during the off-times of the transistor 1 U (I _{soll 2)} = U (I _soll 1). The transistor 1 is turned on via the comparator 5 when

U (I _is ) ≤ U (I _{should be} 1). After switching on the transistor 1, the current setpoint value U (I _{soll 2} ) fed to the comparator 5 _is increased by means of the controllable adder 15 and it applies

U (I _should 2) = U (I _should 1) + U _D. If the current actual value U (I _ist ) ύen ^ reaches the higher current setpoint U (I _soll 1) + U _D , transistor 1 is blocked and at the same time the current setpoint becomes U (I _{should 2} ) switched back to the lower value U (I _should 1). This results in a control characteristic with hysteresis.

3 is. a third embodiment of an electronic Schaltuhgsanordnung for controlling an electromagnetic component shown. The switching transistor 1 is in turn supplied with the supply voltage + U _v via its emitter and is connected via its collector to the electromagnetic component 2 and to the free-wheeling diode 4. The electromagnetic component 2 is in turn connected directly to ground via the measuring resistor R2.

The actual current value U (I _ist ) is tapped at the common connection point between the electromagnetic component 2 and the measuring resistor R ₂ as a voltage value and fed to the first input of a comparator 18. The current input value U (I _soll ) is applied to the second input of the comparator 18. The comparator 18 compares the values U (I _ist ) and U (I _soll ) and controls the monostable multivibrator 6 on the output side whenever U (I _ist ) ≤ U (I _soll ).

The monostable multivibrator 6 controls after triggering by the comparator 18 on the output side the switching transistor 1 at a constant duty cycle t to _a.

Again, a voltage divider 10 with resistors R ₅ , R _{6 is} provided between + U _v and ground. At the common connection point of the resistors R ₅ , R ₆ , the voltage R ₂ / (R ₁ + R ₂ ) * U _{v is} tapped and fed to the first input of a subtractor 19. The current input value U (I _soll ) is applied to the second input of the subtractor 19. The subtractor 19 forms the differential voltage U _D = R ₂ / (R ₁ + R ₂ ) · U _v - U (I _soll ) and passes this value to the first input of a setpoint generator 20.

The peak input U (£) of the AC component of the current actual value is applied to the second input of the setpoint generator 20. The setpoint generator 20 compares the two input signals and outputs a current setpoint U (I _soll ) = U (I _soll l) on the output side whenever U (£)> U _D , as well as a current setpoint U (I _soll ) = U ( I _shall 2) on the output side if U (-_) <U _D. The current setpoint U (I _soll ) is fed to the comparator 18, the subtractor 19 and the first input of a subtractor 21.

The current input value U (I _ist ) is applied to the second input of the subtractor 21. The subtractor 21 forms the difference U (i) = U (I _ist ) - U (I _soll ) and feeds this AC component U (i) of the current actual value to the peak value meter 13.

In the electronic circuit arrangement according to FIG. 3, the magnetic flux ∅ in the electromagnetic component 2 is no longer regulated to a constant value, but the current state of the electromagnetic component 2 (switching state of the switching relay) is detected and the current setpoint U (I _soll ) is switched between two different high values according to the state of the component 2. The rate of rise of the current in the electromagnetic component 2 is evaluated, which is a measure of the inductance L of the component 2 and thus allows a statement to be made about the current state of the electromagnetic component 2. The influences of a changing supply voltage U _v and a changing ohmic voltage drop across R ₁ and R ₂ as a result of a changing current setpoint or a change in resistance due to a change in temperature, they are advantageously switched off. The influence of a change in resistance of R ₁ due to a change in temperature is taken into account when determining the reference value for the setpoint generator 20.

In the circuit arrangement according to FIG. 3, the duty cycle t _one of the raonostable flip-flop 6 triggered by the comparator 18 is constant. The state (switching state) of the electromagnetic component (switching relay) 2 is assessed via the peak value

of the AC component U (i) of the detected current actual value U (I _ist ). It is assumed that with a constant duty cycle t _{one of} the switching transistor 1 the peak value

of the AC component U (i) is dependent on the inductance L of the component 2 and the differential voltage U _D. The differential voltage U _D , which in turn corresponds to the voltage U _v minus the voltage drops across R ₁ , R ₂ , is proportional to the height of the peak value H

a.

The differential voltage Up provides the reference for the peak value for evaluating the state of the component 2

in front. The setpoint generator 20 compares the two quantities Up and U (£). If the electromagnetic component (switching relay) 2 is not energized, the inductance L is low, ie the peak value

large and exceeds the differential voltage Up. Therefore, a high current setpoint U (I _soll 1) is specified as a starting current by the setpoint generator 20. If the electromagnetic component (switching relay) 2 is energized, the inductance L is large, ie the peak value

low. The reference value U _D is determined by the peak value U

no longer reached and the setpoint generator 20 specifies a reduced current setpoint U (I _soll 2) as the holding current. 4 shows a fourth embodiment of an electronic circuit arrangement for controlling an electromagnetic component. This embodiment is essentially of the same construction as the circuit arrangement according to FIG. 2, only in the arrangement according to FIG. 4 the setpoint generator 17 is replaced by a setpoint generator 22.

The first input of the setpoint generator 22 is acted upon by the on-time tein of the switching transistor 1 determined by the time recording device 16. A reference time tref is applied to the second input of the setpoint generator 22. The setpoint device 22 compares the values of t ref and t _and are always a current setpoint U (I _want one) = U (I _want one '') from the output side when _a t> t _ref. The setpoint generator 22 is always a Strorasollwert U (I _want one) = U (I _should 1 *) when t _a <t _ref.

4, the magnetic flux ∅ in the electromagnetic component 2 is not regulated to a constant value, but the instantaneous state of the electromagnetic component 2 is detected and the current setpoint is in accordance with the state of the component 2 between two different levels Values switched. This is the peak value

of the alternating current component U (i) and the evaluation of the state of the electromagnetic component 2 takes place via the on-time tein of the switching transistor 1.

The differential voltage U _D at the time the switching transistor 1 is switched on provides the reference for the peak value

of the AC component. Because the peak value

with constant total resistance R ₁ + R _2i constant inductance L and constant duty cycle tein is proportional to the differential voltage U _D , the influences of a changing supply voltage U _v and a changing voltage drop across R ₁ , R ₂ are switched off by changing the current setpoint. With such a change in U _v and Ig0ll, the differential voltage Up also changes and thus the peak value proportional to this

. The influence of a change in resistance of R ₁ due to an increase in temperature is taken into account when determining the reference value for the setpoint generator 22.

If the electromagnetic component (switching relay) 2 is not yet tightened, the inductance L is small. Thus, the current ira component 2 rises sharply and the. On time tein of the switching transistor 1 is short. The switch-on time tein does not reach the predetermined reference time tref and the setpoint generator 22 consequently emits an increased current setpoint U (I _soll 1 ') as the starting current. When the electromagnetic component (switching relay) 2 is attracted, the current in component 2 rises only slightly due to the large inductance L and the on-time tein of switching transistor 1 is long. The duty cycle exceeds _a t tref the predetermined reference time and the reference value generator 22 is thus a reduced nominal current value U (Isoll 1 '') as the holding current. The operating time t _a of the switching transistor 1 is therefore in each case determined by the time detecting means 16 and the reference value generator 22 outputs, depending on the currently present operating time t on a switching state of the electromagnetic device 2 matched current setpoint before.

This current setpoint predetermined by the setpoint generator 22

U (I _shall 1) is the subtractor 14 and the controllable adder 15 fed. The subtractor 14 subtracts the current setpoint U (I _soll 1) from the evaluated supply voltage R ₂ / (R ₁ + R ₂ ) · U _v and in this way forms the differential voltage U _D at the moment of maintenance of the switching transistor 1. When the switching transistor 1 is switched on, the comparator 5, an increased current command value U (I _soll 2) = U (I _{soll 1)} supplied to _D + U. This increased current setpoint of U (I _{soll 2} ) determines the peak value

C of the AC component, ie the peak value

is proportional to the differential voltage U _D.

If the current U (I _ist ) reaches the value

U (I _Soll 2) = U (I _Soll 1) + U _D , the comparator 5 blocks the switching transistor 1 and the controllable adder 15 simultaneously gives the comparator 5 the reduced current setpoint

U (I _Soll 2) - U (I _Soll 1) for the following switch-on instant of the switching transistor 1 before.

In summary, it should be noted with regard to the electronic circuit arrangements according to FIGS. 3 and 4 that in these arrangements the high pull-in current required for safely pulling in a switching relay is reduced to a lower holding current after the relay has been energized. This enables the operation of an AC switching relay with direct current, as well as a low-loss operation of the switching relay. For safe operation, the pull-in current is only reduced to the holding current if the switching relay has picked up safely. The switching state of the relay is detected in both cases (Fig. 3,4) by evaluating the different magnetic induction of the relay coil (= electromagnetic component ₂ ) in the energized and in the non-energized state by measuring the time constant of the relay coil. Another option for detecting the switching state of the electromagnetic component is to use a mechanical auxiliary contact. The switchover from the high starting current to the lower holding current then takes place depending on the auxiliary contact position.

6 shows a fifth embodiment of an electronic circuit arrangement for controlling an electromagnetic component. The supply voltage U _{v is applied} to a timing element 23 on the input side. On the output side, the timing element 23 emits a current setpoint U (I _soll ), which is compared with an actual current value U (l _ist ) and is then fed to a two-point controller 24. The output signal of the two-point controller 24 is fed to a switching amplifier 25, the further input of which is supplied with the supply voltage Uv. The switching amplifier 25 outputs the voltage U for the electromagnetic component 2 on the output side. The actual current value U (I _ist ) of the electromagnetic component 2 is determined and fed to the comparison point arranged in front of the two-point controller 24.

7A, B, C are the time-dependent curves of the supply voltage U _v , the current setpoint U (I _soll ). and the actual current value U (I _is ) for the circuit arrangement according to FIG. 6. After application of the supply voltage U _v at the time t = 0, the timer 23 specifies an increased current setpoint U (I _soll 1) on the output side in the period 0 <t <to. At time t ₀ , the current setpoint U (I _soll ) is switched to a lower value U (I _soll 2). The difference between the current setpoint and current actual value is fed to the two-point controller 24, which is subject to hysteresis. Depending on the level of the value on the input side, the two-position controller 24 On / off commands to the switching amplifier 25. In this way, the constant supply voltage U _{v is converted} into a pulse duration modulated voltage U and supplied to the electromagnetic component 2. For economic reasons, this self-oscillating circuit is used, which uses the natural inductance of the excitation circuit.

By means of this regulation with the aid of the two-point controller 24, the coil current in the electromagnetic component is kept between two predefinable limit values. This advantageously enables an economical design of the magnetic circuit, in particular in the case of switches operated by the same voltage, the magnetic circuit of which can be reduced at least to the size of a comparable AC-operated switch.

The actual current value U (I _ist ) flowing in the electromagnetic component 2, shown in FIG. 7c, rises from the time t = 0 to a maximum value U (I _{ist 1} ), then falls after the intervention of the two-point controller 24 to a value U (I _{ist 2} ) decreases, rises again to the maximum value, etc. In this first time range specified by the timing element 23, an average actual current value of U (I _{is 3} ) results. At time to, the current drops to a minimum value U (I _{is 5} ), then rises to a value U (I _is 4) after intervention of the two-point controller 24, falls again, and so on Time range an average actual current value of U (I _{is 6} ).

By specifying an increased setpoint for a short duration with the aid of the timing element 23, the surge current required for tightening is thus forced, after which time a current is specified which is just that required to hold the tightened armature Power creates.

FIG. 8 shows a detailed electronic circuit arrangement for the exemplary embodiment according to FIG. 6. Between the positive and the negative

The input voltage is at the supply voltage U _v . A capacitor 26 is connected between the two input terminals. A resistor 27, a diode 28 and a positive output terminal are also connected to the positive terminal. Resistor 27 is connected on the one hand via a Zener diode 29 to the negative input terminal, on the other hand to the timing element 23 and the supply input of an amplifier 30. The timer 23, the further supply input of the amplifier 30 and the emitter of a transistor 31 (NPN type) are also connected to the negative input terminal. The collector of the transistor 31 is connected on the one hand to the diode 28 and on the other hand to a negative output terminal via a current measuring device 32. A connecting line leads from the current measuring device 32 to the negative input of the amplifier 30, ie the actual current value U (I _ist ) is fed to the negative input of the amplifier 30. The positive input of the amplifier 30 is connected to the timing element 23 and receives the current setpoint U (I _soll ).

The output of amplifier 30 is connected to the base of transistor 31. The voltage U is present between the output terminals of the electronic circuit arrangement.

The function of the amplifier 30 corresponds to that of the two-point controller 24 with a reference junction and the transistor 31 to the switching amplifier 25. The electromagnetic component 2, consisting of a coil 33 with a yoke and armature and switch contacts 34, is connected to the output terminals of the electronic circuit arrangement connected.

In a further exemplary embodiment, FIG. 9 shows an electronic circuit arrangement with two-point control and induction value feedback. In a

Addition point 35 is a predetermined induction setpoint B _{sol 1} and an actual induction value K · B multiplied by a factor K _is compared and the difference is fed to a two-point controller 24. The two-point controller 24 issues on / off commands to the switching amplifier 25. The switching amplifier 25 receives the input side, further, the Versorguπgsspannung U _v, and outputs the output side, the coil voltage U off to the electromagnetic component. 2, the occurring in the magnetic circuit of the electromagnetic device 2 Induktioπsistwert B _is detected and fed to a reviewer stage 36th The induction actual value K · B which _{can be taken from} this evaluation stage 36 and is multiplied by the factor K _is fed to the addition point 35. The factor K takes into account that only a partial value of the induction value is measured.

A, B, C The tent-dependent curves of the supply voltage U _v , the actual coil current value I actual and the coil voltage U are shown in FIG. The supply voltage U _{v is present} at the switching amplifier 25 in the period 0 <t <t ₄ . The coil current actual value I _ist rises to a peak value in the period 0 <t <t ₁ and has dropped to a value I ₇ at time t ₁ , which corresponds to a predeterminable induction value, and the two-point controller 24 issues an off command to the switching amplifier 25 , ie the output voltage of the switching amplifier 25, which is equal to the coil voltage, changes from the value U _v during the period 0 <t <t ₁ to the value 0. At the time t ₂ , the coil current reaches the value I ₈ . At the same time, the induction value B _is on one has dropped to a minimum value which results in an ON command from the two-point controller 24 to the switching amplifier 25. Consequently, the supply voltage U _v is again supplied to the electromagnetic component 2 as a coil voltage. At time tg, the coil current Iact again reaches the value I ₇ , while at the same time the induction actual value B _{is at} a maximum value, which results in an off command from the two-point controller 24.

This described control process is repeated in the following, the switching amplifier 25 alternately switching the supply voltage U _v and the voltage 0 as the coil voltage U to the electromagnetic component, so that the coil current actual value I _ist alternately rises and falls within the limit values I ₇ and I ₈ , which corresponds to an average current value I ₉ . After switching off the supply voltage U _v at time t4, the current I _ist drops to the value 0 at time t ₅ .

11 shows the Hall probe used to regulate the actual induction value B _{is shown} in principle. A supply voltage U _{v1 is} applied to a Hall probe 37 with a transistor 38 connected downstream. The emitter of transistor 38 is grounded, while its collector is supplied with a supply voltage U _v2 via a resistor 39. If the Hall probe 37 is brought into a magnetic field, a voltage of different magnitude is present at the base of the transistor 38 depending on the magnitude of the magnetic induction Bist of the field, ie the collector-emitter path of the transistor 38 is switched through depending on the actual induction value Bi _st or locked. In the blocked state, the output voltage U _A between the collector of transistor 38 and ground U _A = U _v2 , in the switched-on state U _A = 0. The characteristic U _A (B _ist ) has a hysteresis Δ B and an average induction value B ₀ .

FIG. 12 shows a detailed electronic circuit arrangement for the exemplary embodiment according to FIG. 9. The supply voltage U _{v is present} between the positive and the negative input terminal. The capacitor 26, the resistor 27, the further resistor 39 and the diode 38 are connected to the positive input terminal. The positive input terminal also forms the positive output terminal of the circuit arrangement. The capacitor 26, the zener diode 29 and the Hall probe 37 with transistor 38 are connected to the negative input terminal. Furthermore, the negative input terminal is connected to the emitter of transistor 38. The Hall probe 37 with transistor 38 is also connected on the input side to the common connection point of Zener diode 29 and resistor 27. This signal input supplies the supply voltage U _v1 . The dashed connecting line in Flg. 12 shows that the Hall probe 37 with transistor 38 is arranged in the yoke 41 of the electromagnetic component (switching device) and is there exposed to the actual magnetic value K · B _ist .

The output of Hall probe 37 with transistor 38 has the output voltage U _A and is connected to the resistor 39 and the base of the transistor 31. The voltage across resistor 39 is designated U _v2 . The collector of transistor 31 is connected to the negative output terminal of the circuit arrangement. The coil 33 of the electromagnetic component 2 is connected between the two output terminals. The switch contacts of the electromagnetic component are designated by reference number 34 and the armature provided for their actuation by reference number 43. Of the Transistor 31 essentially corresponds to the switching amplifier 25 according to FIG. 9, while the two-point regulator 24 with addition point 35 is realized by the arrangement of Hall probe 37 / transistor 38 - resistors 27 and 39.

FIG. 13 shows the circuit arrangement according to FIG. 12 in a simplified basic illustration. The supply voltage U _v is applied to a switching amplifier 44 via the input clerical arenas. The output of the switching amplifier 44 forms the positive output terminal, while the negative output terminal is connected to the negative input terminal. The coil 33 of the electromagnetic component 2 with yoke 41 is connected between the output cleramen. Furthermore, the switch contacts 34 with armature 43 are shown. The coil voltage U is present between the output terminals. The actual coil current value I _ist flows into the coil 33 of the electromagnetic component 2. The current flowing in the yoke 41 and armature 43 is Induktionsistwert B _is. The partial value of the actual magnetic induction value flowing through the Hall probe 37 arranged in the yoke 41 is K · B _is and is fed to the switching amplifier 44 on the input side.

14 shows the mechanical design of an electronic circuit arrangement according to FIGS. 9 to 13. The coil 33 of the electromagnetic component 2 with yoke 41 and armature 43 are enclosed by the switch housing 45. The electronic circuit arrangement according to FIGS. 9 to 13 also built into the housing is built on a printed circuit board 46. The Hall probe 37 connected to the circuit board 46 is arranged in the yoke 41.

By connecting a Graetz bridge circuit All electronic circuit arrangements described can also be operated with an alternating voltage as the supply voltage U _V , as a result of which the disadvantage of the connection polarity is eliminated and further advantages result. The magnetic circuit no longer has short-circuit rings, which reduces the construction volume. The armature has a constant attraction force even when the control voltage passes through zero (supply voltage), so that the usual humming sound disappears. Finally, the one operated by the distinction becomes DC

Switchgear - AC-operated switchgear reduced the necessary type variety by half.

With the electronic circuit arrangements according to the invention, it is also possible in a simple manner to carry out desired time functions, such as Realize switch-on delays or switch-off delays.

Commercial usability:

The invention is used for controlling switching relays and chokes and for monitoring the switching state of switching relays, and for measuring the instantaneous inductance of electromagnetic components under direct current load, such as e.g. Saturation of chokes.

Claims

Expectations

1. Electronic circuit arrangement for driving an electromagnetic component, in particular a throttle or a coil of a magnetic circuit with coil, yoke and armature having electromagnetic switching device, characterized in that a comparator (5.18), a predetermined current value _(to U (I)) and a measured current actual value (U (I _ist )) corresponding to the current in the electromagnetic component (2) _{is present on the} input side and the comparator (5, 18, 30) on the output side as a function of the deviation in the level between the current setpoint value (U (I _soll )) and the current actual value (U (I _is )) a switch (1), in particular a switching transistor, which is located in the main circuit of the electromagnetic component (2) and is supplied with the supply voltage (U _v ) for controlling the electromagnetic component (2).

2. Electronic circuit arrangement according to claim 1, characterized in that a controllable resistor (3) is arranged in the main circuit of the electromagnetic component (2), which is a function of the control deviation between the Scheltel value (

of the alternating current component (U (i)) of the actual current value (U (I _ist )) and the differential voltage (U _D ) which drops across the inductance (L) of the component (2) at the moment when the switch (1) is switched on, can be controlled by a controller (12) is.

3. Electronic circuit arrangement according to at least one of the preceding claims, characterized in that between the output of the comparator (5,18,30) and the control connection of the switch (1) a monostable flip-flop (6) is arranged.

4. Electronic circuit arrangement according to at least one of the preceding claims, characterized in that a measuring resistor (R ₂ ) is arranged in the main circuit of the electromagnetic component (2) for detecting the actual current value (U (I _is )).

5. Electronic circuit arrangement according to claims 2 and 4, characterized in that for detecting the actual current value (U (I _is) ) a controllable resistor (3) bridging voltage divider (R ₃ , R ₄ ) is provided, the divider ratio (R ₃ / R ₄ ) is proportional to the ratio between the ohmic resistances of the electromagnetic component (R ₁ ) and the measuring resistor (R ₂ ).

6. Electronic circuit arrangement according to at least one of the preceding claims, characterized in that a subtractor (9) is provided which has a predetermined current setpoint (U (I _shall 1)) around the average (U (i)) of the AC component (U (i )) of the actual current value (ü (I _ist )) reduced.

7. Electronic circuit arrangement according to claim 6, characterized in that for forming the average

U a smoothing element (8) is provided, to which the AC component (U (i)) of the actual current value (U (I _ist )) can be supplied on the input side.

8. Electronic circuit arrangement according to at least one of the preceding claims, characterized in that a time detection means (16) for determining the duty cycle (t _on) of the switch (1).

9. An electronic circuit assembly according to claim 8, characterized in that the time detecting means (16) comprises a setpoint generator (17,22) is connected on the output side, various nominal current values (U (I _{soll 1))} as a function of the value of the duty cycle (t _on) of Switches (1) releases.

10. An electronic circuit assembly according to claim 9, characterized in that the desired value transmitter (22) on the input side is applied a reference time (t _ref) and the desired value transmitter (22) as a function of the difference between duty cycle (t _on) of the switch (1) and reference time (tref ) outputs two different current setpoints (U (I _should 1)).

11. Electronic circuit arrangement according to at least one of the preceding claims, characterized in that a subtractor (7,21) for forming the AC component (U (i)) of the current actual value (U (I _is )) is provided, the current-side actual value and the Strorasollwert (U (I _soll)) abut.

12. Electronic circuit arrangement according to claim 11, characterized in that the subtractor (7,21) a peak value meter (13) to form the peak value teess

the AC component (U (i)) is connected downstream.

13. Electronic circuit arrangement according to at least one of the preceding claims, characterized in that a subtractor (11, 14, 19) is provided for forming the differential voltage (Up), the input side of the current setpoint (U (I _soll )) and a weighted

Supply voltage value (R ₂ / (R ₁ + R ₂ ) · U _v ) can be supplied.

14. Electronic circuit arrangement according to claim 13, characterized in that for evaluating the supply voltage (U _v ) a voltage divider (10) is provided, the parts ratio (R ₅ / R ₆ ) proportional to the ratio between the ohmic resistances of the electromagnetic component (R ₁ ) and the measuring resistor (R ₂ ).

15. Electronic circuit arrangement according to at least one of the preceding claims, characterized in that a depending on the switching state of the switch (1) controllable adder (15) for current setpoint formation (U (I _shall 2)) is provided, the input side of the differential voltage (U _D ) as well as a first current setpoint (U (I _should 1)).

16. Electronic circuit arrangement according to at least one of the preceding claims, characterized in that a setpoint generator (20) is provided, the input side of the differential voltage (U _D ) and the peak value

of the AC component (U (i)) of the actual current value (U (I _ist) ).

17. Electronic circuit arrangement according to at least one of the preceding claims, characterized in that the comparator (5, 18, 30) is designed as a hysteresis-sensitive two-point controller (24).

18. Electronic circuit arrangement according to claim 17, characterized in that the two-point controller (24) is preceded by a timing element (23) which, during a predetermined period after the supply voltage (U _v ) has been applied, has an increased current setpoint (U (I _soll 1)) and then specifies a reduced current setpoint U (I _soll 2)).

19. Electronic circuit arrangement for controlling an electromagnetic component, in particular a choke or a coil of a magnetic circuit with a coil, yoke and armature. Having electromagnetic switching device, characterized in that the control deviation between an induction setpoint (B _soll ) and an actual induction value (B _ist ) of the magnetic circuit of the electromagnetic component (2) is supplied to a two-point controller (24) and that the two-point controller (24) one with the Controls switching amplifier (25) connected to the electromagnetic component (2) in such a way that the induction value (B _is ) moves within predefinable limit values, the switching amplifier (25) being supplied with the supply voltage (U _v ) on the input side for controlling the electromagnetic component (2) .

20. Electronic circuit arrangement according to claim 19, characterized in that for the induction value control in the yoke (41) of the electromagnetic component (2) arranged Hall probe (37) with a downstream transistor (38) is used.