DE102007027734A1 - Circuit arrangement with a plurality of flyback converter modules and a method for providing a number of 2 * n drive signals for the n electrodes of a dielectrically impeded discharge lamp - Google Patents

Abstract

The present invention relates to a circuit arrangement having a first (EA1) and a second input terminal (EA2) for connecting a supply voltage (U <SUB> ZW </ SUB>), at least a first and a second flyback converter module (SWM1, SWM2), each Flyback converter module (SWM1) comprises: a terminal for connecting a module supply (EA1; K1), a terminal for connecting a reference potential (K1; K2), an electronic switch (S1; S2) having a control electrode, a reference electrode, and a working electrode a first inductance (L1; L3) representing the primary winding of a transformer, a second inductance (L2; L4) constituting the secondary winding of the transformer, a control input coupled to the control electrode of the electronic switch (S1; S2) is, wherein the distance working electrode - reference electrode of the electronic switch (S1, S2) is serially coupled to the first inductance (L1, L3) u nd wherein this series connection between the terminal for connecting a module supply (EA1; K1) and the connection for connecting a reference potential (K1; K2), the series circuits comprising respectively first inductance (L1; L2) and distance working electrode reference electrode of the respective first (EA1) and the second input terminal (EA2) for connection a supply voltage (U <SUB> ZW </ SUB>) are coupled, wherein the ...

Description

Technical area

The The present invention relates to a circuit arrangement with a first and a second input terminal for connection a supply voltage, at least a first and a second Flyback converter module, each flyback converter module having a connection for connecting a module supply, a connection for connecting a reference potential, an electronic Switch comprising a control electrode, a reference electrode and a Working electrode, a first inductance, the represents the primary winding of a transformer, a second inductor, which is the secondary winding represents the transformer and a control input, with the Control electrode of the electronic switch is coupled, comprises where the distance working electrode reference electrode of the electronic Switch is serially coupled to the first inductance and wherein this series connection between the terminal for connecting a Module supply and the connection for connecting a Reference potential is coupled, the series circuits off each first inductance and distance working electrode reference electrode of the respective electronic switch serially between the first and the second input terminal for connecting a Supply voltage are coupled. It also concerns a method of providing a number of 2 * n drive signals for the n electrodes of a dielectrically impeded discharge lamp, where n> = 2 with a corresponding circuit arrangement.

State of the art

A generic circuit arrangement is known from the EP 1 643 816 A2 , This document teaches a plurality of flyback converter modules, there class E converter modules, to be connected in series in the form that their already inside the modules in series connected memory inductances and switching transistors as a whole form a series circuit. The switching transistors of the individual class E converter modules are controlled via a common control signal, so that the individual modules can be synchronized and operate essentially in phase. The switching transistors used for switching on and off of the current of the storage inductors are thus switched synchronously, which takes place by a signal-technical coupling of the individual switching transistors driving control lines in the sense of a common control signal. As a result, the advantage can be achieved that the series connection of the individual modules can be used, so to speak, as a voltage divider switch, dividing the DC supply voltage into the individual modules and thus applying a reduced supply voltage to the individual modules. Thus, a relatively large DC supply voltage can be used without the load capacity of the switching transistors and other components, in which case the transformer at the output of the individual modules must be emphasized in particular, would have to be adapted to this large DC supply voltage.

Problematic in this known circuit arrangement is that they only to operate a complete dielectrically impeded discharge lamp suitable is. To prevent blurring effects when applied dielectrically disabled discharge lamps in the range of LCD screens a dielectrically impeded discharge lamp, however, several separate On electrode areas. On the basis of the cited document Therefore, several electronic ballasts are needed, around the individual electrode areas of such a dielectric to operate disabled discharge lamp. Exactly Accordingly, an electronic ballast is taken per pair of electrodes necessary. The electronic ballasts must be synchronized with each other. Each electronic ballast includes at least one rectifier, as well as a PFC (power factor correction) stage. This results in undesirably high costs.

Presentation of the invention

Of the The present invention is therefore based on the object, a to develop generic circuit arrangement in such a way that they prevent the blurring effects at low implementation costs allows. According to another aspect Another object of the present invention is to provide a Propose method that provides a number of 2 * n drive signals for the n electrodes of a dielectrically impeded discharge lamp allows, wherein n> = 2 applies. According to one Third aspect of the present invention has another object therein, a corresponding e lectronic ballast to provide a dielectrically impeded discharge lamp. According to a fourth aspect of the present invention a further object is to provide a lamp system with such electronic Ballast and a dielectrically impeded discharge lamp provide.

According to the present invention, the first object is achieved by a circuit arrangement with the features of claim 1, the second object by a method having the features of claim 10. The third object is achieved by an electronic ballast having the features of claim 3 and the fourth Task through a lamp system with the features of claim 7.

Of the The present invention is based on the finding that these Tasks can be solved if the individual Flyback converter modules are not connected in series at the output, but each individual module is considered separately. With others Thus, words have a circuit arrangement according to the invention each flyback converter module has a first and a second output connection, wherein the respective second inductance between the respective first and the respective second output terminal is coupled.

One Such circuitry allows the use of actually unfavorable large DC link voltage, which is forcibly generated by the PFC stage, as a supply voltage. By Primary clean circuit of the individual flyback converter modules this is divided into an order of magnitude, so that low demands on the components involved result. Due to the now separate secondary side can be separated individual electrode structures in a dielectric obstructed discharge lamp, in particular in a planon lamp, supply independently of each other. Leave it to achieve a high resolution; Blurring effects can thus reliably avoided. Moreover, they are in a circuit arrangement according to the invention the leakage inductance compared to the reduced known circuit arrangement.

at a preferred embodiment, the circuit arrangement Each flyback module has a control connection to the control input is coupled to the respective flyback converter module. Leave it to apply a different control signal to each flyback converter module, whereby an independent on the other flyback converter modules Control of the respectively connected electrode pair possible is.

A preferred embodiment of an inventive electronic ballast further includes a power factor correction device, wherein the device for power factor correction an input for coupling with a AC source, and a first and a second Output terminal, wherein the first output terminal of the device for power factor correction with the first input terminal of Circuit arrangement and the second output terminal of the device for power factor correction with the second input terminal of Circuit arrangement is coupled. Such an electronic one Ballast allows the control of several Electrode structures of a dielectrically impeded discharge lamp, whereby only one device for power factor correction is provided will need. This still applies to the between one Power connection and the power factor correction device usually coupled rectifier.

Farther preferably comprises an inventive electronic Ballast a control device, wherein the control device is designed to generate a control signal per flyback converter module and to couple to the respective control input. Especially preferred is, if the control device is still designed, the Synchronize control signals with each other.

A particularly preferred embodiment of an inventive Lampensystems is characterized by the fact that the dielectrically impeded Discharge lamp a number of n electrodes, each with a first and a second electrode terminal, wherein the circuitry a number of n flyback converter modules, where n> = 2, where the first and second output terminals of the i-th flyback converter module, with 1 <= i <= n, with the first and the second electrode terminal of the i-th electrode, the dielectric disabled discharge lamp is coupled. It can be provided be that each electrode is designed to emit light a predetermined color.

Especially Preferably, in each case three electrodes are combined, in each case a first electrode is adapted to emit light in the Green color, a second electrode is designed for radiation of light in the color red and a third electrode is designed for Radiation of light in the color blue. Especially in connection with a TFT display (TFT = thin-film transistor = thin-film transistor) can be synchronized control of a such electrode structure of a dielectrically impeded discharge lamp and the corresponding TFT display a particularly high image quality achieve. In particular, blurring effects are almost complete avoided, and a color control when using separated color segments allows.

Further advantageous embodiments will become apparent from the dependent claims.

The with reference to the circuit arrangement according to the invention, the electronic ballast according to the invention and presented the lamp system according to the invention preferred embodiments whose advantages apply accordingly, if applicable, for the inventive method.

Brief description of the drawings)

in the Hereinafter, embodiments of a Circuit arrangement according to the invention and a lamp system according to the invention with reference to the accompanying drawings. Show it:

1 a schematic representation of a first embodiment of a circuit arrangement according to the invention;

2 a schematic representation of a second embodiment of a circuit arrangement according to the invention; and

3 in a schematic representation of an embodiment of a lamp system according to the invention.

Preferred embodiment the invention

1 shows a schematic representation of a first embodiment of a circuit arrangement according to the invention. This has a first EA1 and a second input terminal EA2 for connecting a supply voltage. This is usually the so-called intermediate _{circuit voltage} U _ZW . The circuit arrangement comprises three flyback converter modules SWM1 to SWM3, each flyback converter module SWM1 to SWM3 comprising a connection for connecting a supply for the respective flyback converter module and a connection for connecting a reference potential. In the present case, the connection EA1 forms the connection for the module supply of the flyback converter module SWM1. The terminal K1 forms on the one hand the connection for connecting the reference potential for the flyback converter module SWM1 and on the other hand the connection for the module supply of the flyback converter module SWM2. The same applies to the connection K2 with respect to the flyback converter modules SWM2 and SWM3. For the flyback converter module SWM3, the input terminal EA2 finally forms the connection for the reference potential. Each flyback converter module SWM1 to SWM3 has an electronic switch S1 to S3, each switch S1 to S3 having a control electrode, a reference electrode, and a working electrode. In addition, each flyback converter module SWM1 to SWM3 has a first inductance L1, L3, L5 and a second inductance L2, L4, L6, the first inductance L1, L3, L5 representing the primary winding of a respective transformer and the second inductance L2, L4, L6 is the secondary winding of the respective transformer. Each flyback converter module SWM1 to SWM3 has a separate control input St1, St2, St3 for supplying a respective control signal SE1, SE2, SE3, wherein the respective control input St1, St2, St3 is coupled to the control electrode of the respective electronic switch S1, S2, S3.

The distance working electrode reference electrode of each electronic switch S1, S2, S3 is coupled in series to the respective first inductance L1, L3, L5. This series circuit is respectively coupled between the terminal for connecting a module supply of the corresponding flyback converter module SWM1 to SWM3 and the terminal for connecting a reference potential for the respective flyback converter module SWM1 to SWM3. As it turned out 1 shows, the series circuits of each first inductance L1, L3, L5 and distance working electrode - reference electrode of the respective electronic switch S1, S2, S3 serially coupled between the first EA1 and the second terminal EA2 for connecting a supply voltage U _ZW . According to the invention, a first A11, A21, A31 and a second output terminal A12, A22, A32 are now provided per flyback converter module SWM1, SWM2, SWM3, wherein the respective second inductor L2, L4, L6 between the respective first A11, A21, A31 and the respective second output terminal A12, A22, A32 is coupled. The first A11 and the second output terminal A12 of the flyback module SWM1 represents a first and a second electrode terminal for an electrode E1. The same applies to the flyback converter module SWM2 and the output terminals A21 and A22 with respect to an electrode E2 and for the flyback converter module SWM3 and Output terminals A31 and A32 with respect to an electrode E3.

2 shows a schematic representation of a second embodiment of a circuit arrangement according to the invention. In particular, it shows a series connection of four flyback converter modules SWM1 to SWM4 in an electronic ballast for supplying a dielectrically impeded discharge lamp. A first and in 2 The high-side module SWM1 shown above has a switching transistor S1, here a power MOSFET, a storage inductor L1 with secondary winding L2, a supply electrolytic capacitor C11, a control coupling capacitor C7 and a Zener diode Z1. Serial to the drive coupling capacitor C7, an ohmic resistor R1 is arranged. The storage inductance L1 and the switching transistor S1 are connected in series, the source terminal of the switching transistor S1 being at the bottom of the module-internal reference potential which determines the positive supply potential of the underlying module (S2, L3, L4, C12, C8, R2, Z2). forms.

The drain terminal of the switching transistor S1 is coupled to the lower terminal of the storage inductor L1 whose upper terminal is connected to the so-called intermediate _{circuit voltage} U _ZW , the usually about 450 volts. This DC link voltage U _ZW is generated in a not shown in detail here and in itself conven- tional manner by rectification and conversion with a boost converter from a mains supply voltage.

Parallel to the series connection of the storage inductance L1 and the switching transistor S1 is the supply capacitor C11, which serves to support the supply voltage and therefore designed as a relatively large electrolytic capacitor is.

In Each flyback converter module SWM1 to SWM4 is connected via a respective Control input St1 to St4 a respective control signal SE1 to SE4 fed in, symbolically represented here as a rectangular waveform is. This is in the case of the flyback converter module SWM1 over the ohmic resistor R1 and the drive coupling capacitor C7 applied to the gate of the switching transistor S1. The same applies for the flyback converter modules SWM2 to SWM4. The control signal coupling So it's a pure AC voltage. Between the gate terminal of the switching transistor S1 and its source terminal is a Zener diode Z1 connected, which is the DC level of the coupling capacitor C7 and overvoltages on Gate connection prevented. By clever adjustment of the coupled Ansteuersignalpegels can also be achieved that in case of opening of the switching transistor S1, the drive signal slightly above the Forward voltage of the zener diode Z1 is one and thus superimposed on the drive signal Fault in the zener diode Z1 is shorted. For this short-circuit situation is in the case of the flyback converter module SWM1 the ohmic resistance R1 provided.

Below the described first module SWM1 is a structurally identical second module SWM2 with the correspondingly higher numbered components, wherein the internal (lower) reference potential of the first module SWM1 forms the positive supply potential of the second module SWM2. Corresponding conditions apply to the second SWM2 and the third module SWM3 as well as to the third SWM3 and the fourth module SWM4. The internal reference potential of the fourth module SWM4 forms the second input terminal EA2 via a current measuring resistor R _M.

The supply voltage U _ZW of, for example, 450 V is distributed to the four supply capacitors C11 to C14, as in a voltage divider circuit, so that each of the capacitors is charged to approximately 112.5V. The single module supply voltage could also be reduced by correspondingly higher module numbers.

According to the invention each secondary winding with a first and a second Output terminal coupled to the then a respective electrode a dielectrically impeded discharge lamp can be connected can. For the flyback converter module SWM1 thus form the Output terminals A11, A12 a first and a second electrode terminal for the electrode E1, for the flyback converter module SWM2 thus form the output terminals A21, A22 a first and a second electrode terminal for the electrode E2, for the flyback converter module SWM3 thus form the output terminals A31, A32 have first and second electrode terminals for the electrode E3 and for the flyback converter module SWM4 thus form the output terminals A41, A42 have a first and a second electrode connection for the electrode E4.

3 shows a schematic representation of the structure of a lamp system according to the invention. This includes a rectifier 12 , which has two terminals for an AC supply voltage, in particular the mains voltage U _N. This is followed by a PFC stage 14 for power factor correction, which is preferably designed adjustable. This provides at its output the intermediate circuit voltage U _ZW to the flyback converter modules SWM1 to SWM9 ready. The flyback converter modules SWM1 to SWM9 are interconnected, as is the case in principle with respect to the flyback converter modules SWM1 to SWM3 in FIG 1 or with respect to the flyback converter modules SWM1 to SWM4 in FIG 2 is shown. Each flyback converter module SWM1 to SWM9 is controlled by a control device 16 a control signal SE1 to SE9 supplied. The control device is preferred 16 designed to synchronize the control signals SE1 to SE9 with each other. The control device 16 can be designed to drive the flyback converter modules via Ansteuererkoppelkondensatoren potential-free. Alternatively, highside drivers can be used. Likewise, this would be possible with optocouplers by the required control voltage is generated in each flyback converter module itself.

In the present case, in each case three flyback converter modules control three associated electrodes, wherein a first electrode is designed to emit light in the color green, a second electrode is designed to emit light in the color red and a third electrode is adapted to emit light in the Colour blue. Accordingly, with respect to the flyback converter modules SWM1 to SWM3, the flyback converter module SWM1 drives the electrode E1 which is designed to emit light in the color red, the flyback converter module SWM2 controls the electrode E2, which is designed to emit light in the color green and Flyback module SWM3 the electrode E3, which is designed to emit light in the color blue. Correspond of the flyback converter modules SWM4 to SWM6 with respect to the electrodes E4 to E6 and the flyback converter modules SWM7 to SWM9 with respect to the electrodes E7 to E9. The electrodes E1 to E9 here form the electrodes of a dielectrically impeded discharge lamp 18 ,

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 1643816 A2 [0002]

Claims (10)

Circuit arrangement with - a first (EA1) and a second input terminal (EA2) for connecting a supply voltage (U _ZW ); At least a first and a second flyback converter module (SWM1, SWM2), each flyback converter module (SWM1, SWM2) comprising: a connection for connecting a module supply (EA1, K1); A terminal for connecting a reference potential (K1, K2); An electronic switch (S1, S2) having a control electrode, a reference electrode and a working electrode; A first inductance (L1; L3) representing the primary winding of a transformer; A second inductance (L2; L4) representing the secondary winding of the transformer; A control input coupled to the control electrode of the electronic switch (S1; S2); - wherein the path working electrode reference electrode of the electronic switch (S1; S2) is serially coupled to the first inductance (L1; L3) and wherein this series connection between the terminal for connecting a module supply (EA1; K1) and the terminal for connecting a reference potential ( K1; K2); wherein the series circuits of respective first inductance (L1, L2) and distance working electrode reference electrode of the respective electronic switch (S1; S2) are serially coupled between the first (EA1) and the second input terminal (EA2) for connecting a supply voltage (U _ZW ) ; characterized in that the circuit arrangement comprises, for each flyback converter module (SWM1; SWM2), a first (A11; A21) and a second output terminal (A12; A22), the respective second inductor (L2; L4) being connected between the respective first (A11; A21) and the respective second output terminal (A12; A22). Circuit arrangement according to Claim 1, characterized that the circuit arrangement per flyback converter module (SWM1, SWM2) has a control connection (St1; St2) connected to the control input of the respective flyback converter module (SWM1; SWM2) is coupled. Electronic ballast for operating a dielectrically impeded discharge lamp with a circuit arrangement according to one of claims 1 or 2. Electronic ballast according to claim 3, characterized in that it further comprises a device ( 14 ) for power factor correction, wherein the device ( 14 ) for power factor correction has an input for coupling to an AC voltage source (U _N ) and a first and a second output terminal, wherein the first output terminal of the device ( 14 ) for power factor correction with the first input terminal (EA1) of the circuit arrangement and the second output terminal of the device ( 14 ) is coupled to the power factor correction with the second input terminal (EA2) of the circuit arrangement. Electronic ballast according to one of claims 3 or 4, characterized in that it comprises a control device ( 16 ), wherein the control device ( 16 ) is designed to generate a control signal (SE1; SE2) per flyback converter module (SWM1; SWM2) and to couple it to the respective control input. Electronic ballast according to claim 5, characterized in that the control device ( 16 ) is designed to synchronize the control signals (SE1; SE2) with each other. Lamp system with an electronic ballast according to one of Claims 3 to 6 and a dielectrically impeded discharge lamp, characterized in that the dielectrically impeded discharge lamp ( 18 ) comprises a number of n electrodes (E1 to E9) each having a first and a second electrode terminal, the circuit arrangement comprising a number of n flyback converter modules, where n> = 2, wherein the first and second output terminals of the ith flyback converter module , with 1 <= i <= n, is coupled to the first and second electrode terminals of the i-th electrode of the dielectrically-impeded discharge lamp. Lamp system according to claim 7, characterized in that that each electrode is designed to emit light of one specifiable color. Lamp system according to claim 7, characterized in that that in each case three electrodes (E1, E2, E3) are combined, wherein in each case a first electrode (E2) is designed for radiation of light in the color green, a second electrode (E1) designed is for the emission of light in the color red and a third electrode (E3) is designed to emit light in the color blue. Method for providing a number of 2 × n drive signals for the n electrodes of a dielectrically impeded discharge lamp, where n> = 2, with a circuit arrangement having a first (EA1) and a second input terminal (EA2) for connecting a supply voltage (U _ZW ) , a number of n flyback converter modules, each the flyback converter module (SWM1; SWM2) includes a terminal for connecting a module supply (EA1; K1); a terminal for connecting a reference potential (K1; K2); an electronic switch (S1, S2) having a control electrode, a reference electrode and a working electrode; a first inductance (L1; L3) representing the primary winding of a transformer; a second inductor (L2, L4), which is the secondary winding of the transformer; a control input coupled to the control electrode of the electronic switch (S1; S2); wherein the path working electrode - reference electrode of the electronic switch (S1, S2) is serially coupled to the first inductance (L1, L3) and wherein this series connection between the terminal for connecting a module supply (EA1, K1) and the terminal for connecting a reference potential (K1 K2) is coupled; wherein the series circuits of respective first inductance (L1; L2) and distance working electrode reference electrode of the respective electronic switch (S1; S2) are serially coupled between the first (EA1) and the second input terminal (EA2) for connecting a supply voltage (U _ZW ) ; characterized by the following steps: a) forming a first and a second output terminal (A11; A21) per flyback converter module (SWM1; SWM2), the respective second inductance (L2; L4) between the respective first (A11; A21) and the respective second Output terminal (A12; A22) is coupled; and b) providing a first drive signal at the first output terminal (A11; A22) and a second drive signal (A12; A22) at the second output terminal of each flyback converter module (SWM1; SWM2).