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
• • 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

Definitions

• the present invention relates to a circuit arrangement for operating at least one discharge lamp with a first and a second input terminal for connecting a supply voltage, an inverter comprising at least a first and a second switch, which are coupled in series between the first and the second input terminal and between which a bridge center is defined, a drive ⁇ circuit for at least the first and the second switch with an input for receiving a control signal and a device for generating an auxiliary voltage.
• the auxiliary voltage comprises a first capacitor, a terminal for providing the auxiliary voltage, which is coupled via the first capacitor to a reference potential, a two-position controller having a first input to which the control signal is coupled in an inverted form, a second input which is connected to the Is coupled terminal for providing the auxiliary voltage, and an output, a switch with a control, a working and a reference electrode, wherein the control ⁇ electrode is coupled to the output of the two-point controller, wherein the working electrode with the connection for providing the Auxiliary voltage is coupled, and an ohmic resistance. It also relates to a method for generating an auxiliary voltage in such a circuit arrangement. State of the art
• FIG. 1 A generic, known from the prior art circuit arrangement is shown to illustrate the problem underlying the invention in Fig. 1. It shows a section of an electronic ballast, which is usually connected via a filter circuit, a rectifier circuit, a PFC (Power Factor Correction) circuit to an AC mains. It is powered by the so-called intermediate circuit voltage U zw , which is stabilized by means of a capacitor Cuzw.
• the intermediate ⁇ circuit voltage U ZW present feeds a half-bridge circuit comprising a first switch Sl and a second switch S2, and is usually in the large ⁇ chowskiowski 320 V.
• the half-bridge center point HM is coupled via a lamp inductor L with a discharge lamp La, the a firing capacitor Ci is connected in parallel, and is coupled via a coupling capacitor C ⁇ to a reference potential.
• It has a controller 10, which can be digitally controlled via an interface 12, for example according to the DALI standard. In standby operation, ie when deactivated alternating ⁇ judge, the controller 10 requires a power supply of approximately 2 mA, in normal operation, ie when the change judge ⁇ is in operation, a power supply of approximately 30 mA.
• An "on" signal at the interface 12 leads to ⁇ that a half-bridge driver circuit 14 starts its operation and controls the switches Sl and S2 according to a specification.
• the interface evaluation carried out by the controller 10 must also be in the "off" state of the output circuit 16, that the inverter with the switches Sl and S2, the lamp inductor L and the lamp La including wiring, be ready for use at any time, for example, to ei ⁇ nen new "on" command to receive and evaluate NEN necessary to always supply the controller 10 in the "off” state with a voltage. Accordingly, in order to always keep in readiness the interface 12, arise standby losses that are generally unwanted ⁇ wishes.
• the known solution derives the standby current required for the controller 10 via an ohmic resistor R F and a two-point controller SSD controlled via a switch Q ISS directly from the intermediate circuit voltage U zw .
• the two-point controller SSD the control signal, which serves to turn on the half-bridge driver 14, supplied in an inverted form, so that the two-position controller starts its operation when the half-bridge driver 14 is turned off.
• the controller 10 is no longer supplied through its operating power supply circuit 18 with voltage, wherein the operating supply circuit herein includes by way of example a capacitor C2, and two diodes Dl and D2, but via a provided at a capacitor Cvcc auxiliary voltage V C c • A A ⁇ gear 20 of the two-point controller SSD is used to measure the voltage V C c.
• the drawn in Fig. 1 power source ISS can be realized by an integrated circuit, in a very simplified form, however, also by an ohmic resistance. According to FIG. 1, the standby supply at the capacitor C V cc is only active when the output circuit is switched off via the interface 12.
• the two-point controller SSD keeps the auxiliary voltage V C c over the switched with the switch Q ⁇ S s current source ISS kon ⁇ constant by depending on the power consumption and height of the intermediate circuit voltage U zw varies the duty cycle.
• the standby power dissipation is in this solution, about 0.5 to 1 W.
• the required two-point regulated power source ⁇ is already integrated in an advantageous manner in some handelsüb ⁇ handy half-bridge drivers.
• circuit arrangement (not shown) solves the problem of an additional auxiliary power supply for normal "on" operation in that the circuit arrangement comprises a step-down divider which generates a regulated auxiliary voltage and allows auxiliary voltage generation not only in standby mode but also in normal "on” operation, whereby standby power losses of 0.3 to 0.8 W can be achieved.
• the disadvantage is that such a circuit arrangement is relatively expensive and requires a large number of components.
• the object of the present invention is therefore to develop a generic circuit arrangement or a generic method such that they basically allow a lower standby power loss with cost-effective implementation.
• the present invention is based on the finding that the standby power loss can be significantly reduced by using a transformer.
• the transformer is used as a flux converter, wherein the primary winding is coupled to the switch Q ISS , that a current through the primary winding leads to a corresponding to the transmission ratio of the transformer modified current through the secondary winding, wherein the secondary winding with the capacitor C V cc is coupled, that a current through the secondary winding leads to a charging of the capacitor C V cc.
• the primary winding and the ohmic resistance are connected in series and this series circuit is gekop- pelt between the reference electric ⁇ de of the switch and the first input terminal.
• the device for generating the auxiliary voltage further comprises a first diode, which is connected in parallel to the series circuit of the primary winding and the ohmic resistor and is arranged so that it allows a free running of the current through the primary winding, and a second diode, the secondary winding ⁇ is connected in series, wherein the series circuit of secondary winding and second diode between the reference potential and the terminal for providing the auxiliary voltage is coupled.
• the first and second diodes are preferably designed as fast-recovery diodes.
• a current source is coupled between the working electrode of the switch and the terminal for providing the auxiliary voltage. This is preferably realized particularly cost-effective by an ohmic resistance.
• a further category of embodiments solves the second problem mentioned above in connection with the prior art: it has the advantage that it not only enables a reduction of the standby power loss, but also a continuous auxiliary voltage generation, ie an auxiliary voltage for the supply of the Controller also in normal operation of the output circuit. This eliminates the operating supply circuit discussed in connection with the prior art.
• the device for generating an auxiliary voltage further comprises a second capacitor having a first and a second terminal, wherein the capacitor is coupled to the bridge center and the primary winding such that a capacitive displacement current flow through the primary winding can.
• this embodiment can also generate a current through the secondary winding during normal operation and can be used to charge the capacitor C Vcc and thus to provide an auxiliary voltage to the controller.
• the auxiliary voltage generating device further comprises a third diode, the primary winding being coupled to the first input terminal via the third diode, the third diode being arranged to allow current to flow from the first input terminal to the primary winding the connection point between the primary winding and the third diode is coupled to the second terminal of the second capacitor.
• the device for generating an auxiliary voltage further comprises a third capacitor, which is connected in parallel to the ohmic resistance.
• a third capacitor which is connected in parallel to the ohmic resistance.
• a zener diode is connected in parallel with the first capacitor. This protects the provided auxiliary voltage against overvoltage.
• Figure 1 is a schematic representation of a known from the prior art circuit arrangement for operating at least one discharge lamp.
• Figure 2 is a schematic representation of a first embodiment of an inventive circuit ⁇ arrangement for operating at least a discharge lamp.
• Figure 3 is a schematic representation of a second embodiment of an inventive circuit ⁇ arrangement for operating at least a discharge lamp.
• Fig. 4 shows a schematic representation of a third exemplary embodiment of an inventive circuit ⁇ arrangement for operating at least a discharge lamp.
• FIG. 2 The embodiment of a circuit arrangement according to the invention shown in FIG. 2 furthermore has the operating supply circuit 18 known from FIG. 1 for the controller 10.
• the operating supply circuit 18 known from FIG. 1 for the controller 10.
• it comprises a transformer TR whose primary winding PW is arranged in series with the ohmic resistor R F.
• the switch Q ⁇ S s becomes conductive due to appropriate control by the two-point controller SSD, a current flows from the intermediate circuit voltage U zw through the primary winding.
• ment PW and the ohmic resistance R F via the switch Qiss and the current source ISS to charge the capacitor C V cc.
• the primary winding PW can be freed via the ohmic resistor R F and a diode D F.
• the secondary winding SW feeds the capacitor Cvcc via a diode D C c, at which the auxiliary voltage V C c is provided.
• the freewheel ⁇ diode D F provides with the resistor R F for the demagnetization of the transformer TR.
• the standby mode is effective and the two-point regulator SSD is enabled. If the two-position controller SSD determines that the auxiliary voltage V cc has fallen below the lower threshold of the two-level controller SSD by sensing its input 20, the current source ISS is switched on via the switch Q ⁇ S s.
• the embodiments of circuit arrangements according to the invention according to FIG. 3 and according to FIG. 4 do not require a separate operating supply circuit for the controller 10, ie the controller 10 is also connected in normal operation when the output circuit 16 is in operation via the transponder.
• Transformer TR supplied with power.
• the resistor R F is a capacitor C S / F connected in parallel.
• the output circuit 16 is activated and simultaneously the two-point controller SSD is deactivated.
• the standby auxiliary voltage generation see the comments on Fig. 2, shut down.
• the switch Q .sigma..sub.s s separates the current source ISS from the auxiliary voltage V C c.
• the Wech ⁇ selrichter comprising the switches Sl and S2, switches the potential at the half-bridge center point HM with a given before ⁇ frequency alternating between U ZW and ground back and forth.
• Step 1 The voltage at the half-bridge center HM of the output circuit 16 decreases from the intermediate circuit voltage U zw to ground:
• the capacitor C s via the primary winding PW, the parallel circuit of the ohmic resistor R F and the capacitor C S / F and charged via the switch S2 to the intermediate circuit voltage U zw .
• This is done with a time constant which results from the ohmic resistance R F , the capacitor C S / F and the transformed load at the terminal at which the auxiliary voltage V C c is supplied to the controller 10.
• the secondary winding SW of the transformer TR charges the capacitor C V cc via the diode D C c.
• the transmitted energy can be opti ⁇ mized and adjusted.
• the capacitor C s was 150 pF
• the transmission ratio ü of the transformer TR was 10
• the ohmic resistance R F equal to 5.6 k ⁇
• the capacitor C S / F was 6.8 nF.
• an auxiliary voltage of V cc equal to 15 V could be generated, which was loadable at 30 mA.
• a Zener diode D z can be provided as ge ⁇ dashed located.
• Step 2 The voltage at the half-bridge center HM of the output circuit 16 rises from ground to the intermediate circuit voltage U zw :
• the capacitor C s via the first switch Sl and the diode D F is discharged. It is thus available again for the supply of a charging current for the next falling edge.
• the capacitor C s can be dimensioned very small, in ⁇ play, 100 to 150 pF.
• the embodiment of a circuit arrangement according to the invention shown in FIG. 4 is a variant of that shown in FIG. Here, however, the capacitor C s is charged via the diode D 3 and the switch S2. An energy transfer takes place here during the unloading process of the Instead of the capacitor C s, which takes place through the switch Sl, the Pri ⁇ märwicklung PW of the transformer TR, the parallel sound processing ⁇ of ohmic resistor R and the capacitor C F S / F and the diode D F.
• the charging energy can be adjusted via the transmission ratio ü of the transformer TR and the time constant effective during the respective charging process.
• the time constant is chosen in particular such that a full transhipment of the capacitor C s for generating a maximum current-time area by the primary winding PW is made possible.

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• Dc-Dc Converters (AREA)
• Circuit Arrangements For Discharge Lamps (AREA)

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• 2007
  • 2007-04-23 AT AT07728411T patent/ATE553633T1/de active
  • 2007-04-23 US US12/596,989 patent/US8098022B2/en not_active Expired - Fee Related
  • 2007-04-23 EP EP07728411A patent/EP2138015B1/fr not_active Not-in-force
  • 2007-04-23 KR KR1020097024371A patent/KR101387051B1/ko not_active IP Right Cessation
  • 2007-04-23 WO PCT/EP2007/053954 patent/WO2008128575A1/fr active Application Filing
  • 2007-04-23 CN CN2007800527041A patent/CN101658074B/zh not_active Expired - Fee Related

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