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
  • 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
  • H05B41/2825—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 bridge converter in the final stage
  • H05B41/2827—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 bridge 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
  • H05B41/36—Controlling
  • H05B41/38—Controlling the intensity of light
  • H05B41/382—Controlling the intensity of light during the transitional start-up phase

Definitions

• the invention relates to a ballast for at least one pair of gas discharge lamps operated in parallel according to the preamble of claim 1.
• ballast technology So far it has been assumed in ballast technology that two separate resonant circuits are also required for 2-lamp operation. This is because it has been assumed that when a common resonant circuit is used for both lamps, after the one lamp has been ignited, the resonant circuit voltage breaks down and is no longer sufficient to ignite the second lamp. As a rule, it can be assumed that both lamps are not the same
• the invention has for its object that known ballast
• the ballast according to the invention works with only a single resonant circuit despite the conceptual hindrance described above.
• the cause apparently lies in the effect of the balancing transformer.
• the current flowing through this lamp and the associated winding of the balancing transformer causes a voltage in the other winding which is superimposed on the voltage supplied by the resonant circuit (normally the voltages are compensated for by the two windings of the balancing transformer the opposite direction).
• the above-described superimposition of the voltages on the lamp which has not yet ignited causes the lamp to also ignite.
• the ignition of the lamp can be controlled by monitoring the lamp current. If it is found that after the first lamp has been ignited, the second Lamp does not ignite, so as before, the frequency of the inverter can be lowered to near the resonance frequency of the resonant circuit, with the result that the ignition voltage on the second lamp, which has not yet ignited, is increased. This then usually leads to the ignition of the second lamp.
• ballast An exemplary embodiment of a ballast according to the invention is described below with reference to the single drawing.
• the ballast shown in the drawing has a bridge rectifier G, which is connected to the network. The one generated by the rectifier G.
• the DC voltage is fed to an inverter W R , which has an asymmetrical output.
• the inverter W R is supplied with a DC voltage U DC generated by the rectifier G.
• the inverter W R contains two switch elements connected in opposite directions in a known manner. The switching frequency can be changed. In this way, the inverter WR generates one at its output
• a series resonant circuit is connected, which consists R and a resonant capacitor CR of a choke L.
• the alternating voltage dropping across the resonance capacitor C R is supplied to two pairs of lamps L 1 , L 2 and L 3 , L 4 to be supplied via an isolating capacitor C T.
• the isolating capacitor C T can also be provided between the inverter WR and the reactor LR. It is drawn in dashed lines in the drawing and is drawn with C T with a dash above.
• a first balancing transformer Tsi is provided for the first pair of lamps L 1 , L 2 , which has two windings W S 1 , W S2 acting in the opposite direction. One end of these two windings is connected to the separating capacitor C T
• each of the two windings W S1 , W S2 is connected to an electrode of one of the two lamps L 1 , L 2 .
• the other electrode of the two lamps L 1 , L 2 is connected to ground via a resistor R 1 , R 2 .
• the current flowing through the lamp L 1 generates a voltage drop U L1 across the resistor R 1 , which is used as a measured variable for the lamp current.
• a voltage UL drops 2 which is used as a measured variable for the lamp current of the lamp L2.
• the lamps L 1 and L 2 are heated directly, the two heating filaments being connected by heating capacitors C H1 and C H2 .
• T S2 provided with two windings W S3 , W S4 acting in opposite directions. Again, the two windings are connected at one end, and the
• connection point of the two windings is connected via the isolating capacitor C T to the connection point of the choke L R and the resonance capacitor C R.
• the other ends of the two windings W S3 , W S4 are each connected to one electrode of the two lamps L 3 , L 4 .
• the other electrodes of the two lamps L 3 , L 4 are directly connected here.
• the connection point is with a
• the heating filaments of lamps L 3 , L 4 are heated by means of a heating transformer T H1 , T H2 .
• a heating transformer T H1 , T H2 an input winding W H1, W H4 of the two heating transformers is supplied with a heating voltage U H.
• the heating transformer T H1 has two output windings W H2, W H3 , one of which is connected to a heating coil of the lamp L3.
• the heating transformer T H2 has two output windings W H5, W H6 , each of which is connected to one of the two heating filaments of the lamp L 4 .
• the frequency of the inverter W R is chosen so that it is relatively far above the resonance frequency of the choke L R and the resonant capacitor C R formed series resonant circuit. In this case, the voltage drop across the resonant capacitor C R is relatively small, so that none of the
• Lamp of each lamp pair first.
• the current flowing through the lamp induces in the winding of the corresponding one associated with the other lamp
• Balancing transformer a voltage that is the ignition voltage of the other
• Lamp overlaid with the result that the other lamp also ignites. If the other lamp is not ignited, which can be determined for example in the case of the lamps L 1 , L 2 by the voltages U L1 , U L2 , the frequency of the
• the resonance frequency of the series resonance circuit is approaching. In this way, the ignition of the second lamp is ultimately forced.
• Lamp pairs only a single series resonance circuit is provided. This measure allows the ballast according to the invention to be manufactured more easily and cheaply than previously.
• a single balancing transformer (not shown) with four windings can be provided in the present case, two of which each act in opposite directions.

Landscapes

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

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6476455

Family Applications (1)

Country Status (9)

Cited By (4)

Families Citing this family (10)

Citations (3)

Family Cites Families (3)

• 1992
  • 1992-12-23 DE DE4243955A patent/DE4243955B4/de not_active Expired - Lifetime
• 1993
  • 1993-10-28 EP EP93924069A patent/EP0676121B1/de not_active Expired - Lifetime
  • 1993-10-28 AT AT93924069T patent/ATE148297T1/de active
  • 1993-10-28 ES ES93924069T patent/ES2097550T3/es not_active Expired - Lifetime
  • 1993-10-28 DE DE59305294T patent/DE59305294D1/de not_active Expired - Lifetime
  • 1993-10-28 AU AU53715/94A patent/AU5371594A/en not_active Abandoned
  • 1993-10-28 WO PCT/EP1993/002995 patent/WO1994015444A1/de active IP Right Grant
  • 1993-12-21 ZA ZA939579A patent/ZA939579B/xx unknown
• 1995
  • 1995-05-31 FI FI952655A patent/FI111791B/fi not_active IP Right Cessation
  • 1995-06-22 NO NO952517A patent/NO308690B1/no not_active IP Right Cessation

Patent Citations (3)

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