Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
  • H05B41/14—Circuit arrangements
  • H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
  • H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
  • H05B41/14—Circuit arrangements
  • H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
  • H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
  • H05B41/282—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices
  • H05B41/2821—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices by means of a single-switch converter or a parallel push-pull converter in the final stage
  • H05B41/2822—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices by means of a single-switch converter or a parallel push-pull converter in the final stage using specially adapted components in the load circuit, e.g. feed-back transformers, piezoelectric transformers; using specially adapted load circuit configurations
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
  • H05B41/14—Circuit arrangements
  • H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
  • H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
  • H05B41/288—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices and specially adapted for lamps without preheating electrodes, e.g. for high-intensity discharge lamps, high-pressure mercury or sodium lamps or low-pressure sodium lamps
  • H05B41/292—Arrangements for protecting lamps or circuits against abnormal operating conditions

Definitions

• the present invention relates to an electronic ballast for operating at least one discharge lamp having an input with a first and a second input terminal for coupling to a DC supply voltage, wherein the second input terminal is connected to an external reference potential, a load circuit having an output with a first and a second output terminal for connecting the at least one discharge lamp, a choke converter comprising a converter choke, a converter diode and a converter switch, the converter choke being serially coupled between the first input terminal and the load circuit, a drive circuit configured to convert the converter switch in To drive operation with an RF signal, wherein a first capacitance is defined by the areas of the electronic ballast, which are connected in operation with an RF voltage, whereby a first voltage is defined, which in operation on the e The second capacitance is defined by the areas of the electronic ballast which, during operation, are supplied with a DC voltage with respect to an internal reference potential.
• choke converters are converters in which current is taken from the supply voltage or fed back there during each working cycle.
• Two important representatives are the Bück converter and the boost converter.
• Such converters have a converter choke, a converter diode and a converter switch, wherein the converter choke is coupled in series between the first input terminal and the load circuit.
• Common-mode chokes are often used in the mains input for the reduction of conducted common-mode noise. In difficult cases, however, this measure is often insufficient.
• a method for active compensation of common-mode noise is known for further improvement. Based on the teaching of this document, for example, an opposite to the high-frequency half-bridge voltage can be generated. Since both voltages have a capacitive effect on the coupling the resulting disturbances due to their opposite phase.
• this principle is not yet successfully applied, since the generation of an anti-phase voltage is possible only with great effort. Especially with frequency components above 1 MHz, the compensation no longer works satisfactorily, since the currents involved are not arbitrarily phase-locked as a result of the capacitances involved.
• the present invention is therefore based on the object of developing a generic electronic ballast in such a way that it is distinguished by as few common-mode noise as possible, in particular also in the case of implementation without a metallic housing. This object is achieved by an electronic ballast with the features of claim 1.
• a first capacitance is defined by the areas of the electronic ballast that are connected to an RF voltage during operation. As a result, in operation over this first capacitance a first voltage drops which is related to the external reference potential.
• a second capacitance is defined by the areas of the electronic ballast which, in operation, are supplied with a DC voltage in terms of HF in terms of an internal reference potential. If now it is possible to change the internal reference potential of the device in phase opposition to the interference source, ie to change the voltage which drops above the first capacitance, this can reduce the common-mode noise, which can be fully compensated in the case of I-drop.
• At least one component is coupled between the internal and the external reference potential, over which a second voltage drops in operation, which is opposite in phase to the first voltage.
• an HF current flowing via the first capacitance to the external reference potential is produced.
• the circuit part which has no interference with respect to the external reference potential without the additional component that is, the circuit part which is characterized by the second capacitance, caused by the insertion of the additional device that an HF current flows to the external reference potential, which is in phase opposition to the RF current generated by the first capacitance, the said disturbances can be reduced or even eliminated.
• the additional component so that a voltage swing is introduced in the circuit part, which would be without the additional component at a constant potential.
• this latter effect is exploited by suitable design in order to reduce or even compensate for the disturbing effect due to the first capacity.
• the at least one component represents a compensation inductance. This enables a particularly cost-effective implementation of the invention.
• the compensation inductance is preferably 0.01 to 0.9 times the inductance of the converter choke. This results in a clear demarcation to the known prior art current-compensated chokes based on a completely different principle. In the case of current-compensated reactors, the two reactors must have the same inductance in order to avoid magnetization due to the alternating current of the mains.
• a snubber is coupled parallel to the compensation inductance. This allows the compensation behavior at very high frequencies, for example, from 5 MHz, improve.
• the snubber preferably comprises the series connection of a capacitor and an ohmic resistor.
• the compensation inductance is coupled to the converter choke.
• a magnetic coupling is achieved, whereby the electrical properties, in particular the frequency response, of the two inductances are adjusted.
• the compensation inductance is wound on the same core as the converter inductor.
• Converter chokes often have an additional winding for detecting the demagnetization of the converter choke. This results in the possibility of a particularly preferred embodiment of the present invention: In this case, this additional winding represents the compensation inductance. As a result, no additional inductance has to be used, as a result of which the winding structure is considerably simplified.
• Inductors which have been developed for use in inductance-type inductance choke converters can be adopted without modification in order to realize the present invention.
• the implementation of the present invention can be implement by adapting the PCB.
• the electronic ballast has no metallic housing and / or no protective conductor connection.
• the choke converter can represent a boost converter, wherein the converter diode is coupled in series between the converter choke and the load circuit, wherein the connection point between the converter choke and the converter diode is coupled to the internal reference potential via the converter switch.
• FIG. 1 shows a schematic representation of a study of an electronic ballast
• FIG. 2 shows a first exemplary embodiment of an electronic ballast according to the invention
• FIG. 3 shows a second embodiment of an electronic ballast according to the invention
• Fig. 4 shows a third embodiment of an electronic ballast according to the invention. Preferred embodiment of the invention
• Fig. 1 shows a schematic representation of a study of the present invention using the example of an electronic ballast with a throttle converter.
• the electronic ballast 10 is fed on the input side from a DC voltage source El.
• the DC voltage source El may represent an AC voltage source followed by a rectifier.
• the throttle converter 12 includes a converter inductor Ll, a converter diode Dl and a converter switch Sl, which is driven by a drive circuit, not shown, as is known in the art from the prior art. After the converter choke a storage capacitor Cl is arranged, the load circuit R L is connected in parallel.
• the negative terminal of the DC voltage source El is coupled to an external reference potential M ext , while the switch Sl of the inductance converter 12, the capacitance Cl and the load circuit R L are coupled to an internal reference potential M int .
• a compensation inductance L K is connected in series with the converter inductor L 1 .
• the voltages applied to the two inductances are exactly proportional to one another assuming ideal components.
• Boost converter Ll is coupled to the positive output of the voltage source El. Now, if the compensation inductor L ⁇ serially coupled to the converter choke Ll, so to win first nothing.
• the coupling capacity to the environment is referred to herein as Chi and therefore relatively small.
• Chi thus contribute to all areas of the electronic ballast, which are supplied during operation of the electronic ballast with an RF voltage.
• all components which are supplied with a DC voltage with respect to the internal reference potential M int during operation of the electronic ballast HF contribute to a second coupling capacitance Ci 0 .
• the embodiment shown in FIG. 3 moreover comprises a snubber S n , which in turn comprises the series connection of a capacitor C s and an ohmic resistance R s and is coupled in parallel to the inductance L K.
• This snubber S n enables an improvement of the compensation at high frequency ranges, preferably from 5 MHz.
• the capacitance C s is 1.5 nF
• the ohmic resistance R s is 6.8 ⁇ .
• the compensation inductance L ⁇ is realized by an auxiliary winding, which normally serves to detect the demagnetization of the converter inductor Ll.
• the auxiliary winding L ⁇ on the one hand to the internal M int , on the other hand connected to the external reference potential M ext .
• the compensation inductance L ⁇ is used according to the invention, it can also serve to detect the demagnetization of the converter inductor L 1.
• the voltage U ZCD dropping across the compensation inductance L ⁇ is coupled to the input ZCD of a corresponding control device.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Circuit Arrangements For Discharge Lamps (AREA)
• Dc-Dc Converters (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=42357467

Family Applications (1)

Country Status (8)

Families Citing this family (1)

Family Cites Families (11)

• 2009
  • 2009-07-30 DE DE102009035371.2A patent/DE102009035371B4/de not_active Expired - Fee Related
• 2010
  • 2010-06-21 EP EP10728160A patent/EP2420109A1/de not_active Withdrawn
  • 2010-06-21 WO PCT/EP2010/058685 patent/WO2011012373A1/de active Application Filing
  • 2010-06-21 CN CN201080017793.8A patent/CN102422720B/zh not_active Expired - Fee Related
  • 2010-06-21 JP JP2012522058A patent/JP5538538B2/ja not_active Expired - Fee Related
  • 2010-06-21 AU AU2010278193A patent/AU2010278193A1/en not_active Abandoned
  • 2010-06-21 US US13/382,301 patent/US8587210B2/en not_active Expired - Fee Related
  • 2010-06-21 KR KR1020127005577A patent/KR20120052379A/ko not_active Application Discontinuation

Non-Patent Citations (1)

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