EP0620700A1 - Ballast électronique - Google Patents

Ballast électronique Download PDF

Info

Publication number
EP0620700A1
EP0620700A1 EP93106095A EP93106095A EP0620700A1 EP 0620700 A1 EP0620700 A1 EP 0620700A1 EP 93106095 A EP93106095 A EP 93106095A EP 93106095 A EP93106095 A EP 93106095A EP 0620700 A1 EP0620700 A1 EP 0620700A1
Authority
EP
European Patent Office
Prior art keywords
circuit
voltage
lamp
arrangement according
pulse width
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP93106095A
Other languages
German (de)
English (en)
Inventor
Heinrich Korte
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to EP93106095A priority Critical patent/EP0620700A1/fr
Publication of EP0620700A1 publication Critical patent/EP0620700A1/fr
Withdrawn legal-status Critical Current

Links

Images

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
    • H05B41/295—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 with preheating electrodes, e.g. for fluorescent lamps
    • H05B41/298—Arrangements for protecting lamps or circuits against abnormal operating conditions
    • H05B41/2981—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions
    • H05B41/2985—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions against abnormal lamp operating conditions
    • 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
    • H05B41/39—Controlling the intensity of light continuously
    • H05B41/392—Controlling the intensity of light continuously using semiconductor devices, e.g. thyristor

Definitions

  • the present invention relates to a circuit arrangement for the high-frequency operation of a low-pressure discharge lamp.
  • Ballasts for high-frequency low-pressure discharge lamps have the task of controlling the preheating of the lamp electrodes before the discharge lamp is ignited and the lamp operation after the ignition.
  • the current flow in the lamp circuit is determined by the switching behavior of a switching transistor, which in turn is controlled by a control circuit.
  • the switching transistor has to conduct the current through the lamp circuit both in the preheating phase before ignition of the discharge lamp and during lamp operation. In the event of malfunctions, overvoltages can occur due to the switching inductances contained in the lamp circuit, which can destroy the switching transistor if the reverse voltage is exceeded. It is to reduce the risk of transistor breakdown in the event of overvoltages possible to use transistors with high reverse voltage, which is disadvantageous, however, since such transistors with high reverse voltage are characterized by a deteriorated switching behavior.
  • the object of the present invention is therefore to provide an improved circuit arrangement with which a safe starting behavior of low-pressure discharge lamps and safe lamp operation under protection against overvoltages and overcurrents is made possible.
  • FIG. 1 shows, as circuit components of the circuit arrangement according to the invention, a voltage supply 10, a lamp generator 20, a control circuit 30, which is the pulse width regulator 32, the current limiting circuit 34 and the voltage limiting circuit 36, and a start-up circuit 40. These modules are described in detail below.
  • the voltage supply is designed as a standard rectifier circuit, which consists of the bridge rectifier D1 - D4 and the downstream smoothing capacitors C1, C2.
  • the rectifier is supplied with mains voltage.
  • the lamp generator 20 is constructed as a single-ended high-frequency generator with a switching transistor T2.
  • the lamp generator contains a lamp resonant circuit (L1, L2, C4, C5) which is formed by the switching inductance L1 and a series resonant circuit consisting of the resonant capacitor C4, the auxiliary inductor L2 and the heating capacitor C5.
  • the function of the series resonant circuit (C4, L2, C5) is that when the lamp is not yet ignited, an increased voltage across the capacitor C5 has a favorable effect on the ignition, while on the other hand the auxiliary inductance L2 serves to reduce the lamp current peak value during lamp operation.
  • the clock frequency of the switching transistor T2 is selected so that it corresponds to the resonance frequency of the lamp resonant circuit (L1, L2, C4, C5).
  • the power supply to the lamp generator 20 takes place via the lamp electrode LE1 of the low-pressure discharge lamp LL, so that, in the event of lamp failure, e.g. B. by a blown electrode or other interruption, the entire circuit arrangement remains free of voltage.
  • the switching transistor T2 operated with the resonant frequency of the lamp resonant circuit (L1, L2, C4, C5) is controlled by the pulse width controller 32, which is the actual control component the control circuit forms.
  • the pulse width controller 32 has both the function of generating the switching clock for the switching transistor T2 and also comparing an actual voltage derived from the lamp generator with an internal target voltage and regulating the width of the switch-on pulses of the clocked switching transistor T2 accordingly.
  • the TARGET voltage can be permanently set via an internal reference voltage source REF.
  • the actual voltage is generated using the current limiting circuit 34.
  • the voltage drop across the emitter resistor R4 of the switching transistor is rectified and smoothed and applied to the control input IST of the pulse width regulator 32.
  • the function of the current limiting circuit 34 is such that when the current through the switching transistor T2 increases, the voltage across the emitter resistor R4 rises, so that the level of the ACTUAL controlled variable increases in comparison with the TARGET voltage, whereupon the pulse width controller 32 increases the width of the switch-on pulses of the switching transistor T2 reduced. This ensures that the current through the transistor T2 and the current through the lamp generator 20 are kept almost constant, so that the power of the fluorescent lamp LL and thus its brightness is constant.
  • the control circuit 30 further includes a voltage limiting circuit 36, which serves to avoid overvoltages on the switching transistor T2.
  • the collector voltage of the switching transistor T2 is applied to the base of the transistor T1 via a voltage divider R2, R3. If one is exceeded critical voltage at the collector of the switching transistor T2, the base-emitter voltage of the transistor T1 is also exceeded, so that it becomes conductive and thus the internal reference voltage applied to the pulse width regulator input SOLL is reduced.
  • the ACTUAL control variable derived from the emitter resistor R4 is compared with a reduced TARGET voltage and the transistor ON time is accordingly reduced until the voltage at the collector of the switching transistor T2 has dropped below the critical value.
  • the control circuit 30 requires a supply voltage of around 16 V. During the operation of the fluorescent lamp LL, this supply voltage is supplied by the secondary inductance L10 of the switching inductance L1. Before the fluorescent lamp LL is ignited, the supply voltage is provided by the starting circuit 40.
  • the start-up circuit 40 is connected to the mains voltage supply via the resistors R10, R11 and the lamp filaments LE1, LEZ.
  • the capacitor C7 is charged via the resistors R10 and R11.
  • the thyristor T5 is ignited and the energy stored in the capacitor C7 is delivered to the control circuit.
  • the thyristor T5 remains fired. Otherwise, T5 blocks after capacitor C7 has discharged and charging of C7 begins again.
  • connection of the charging resistors R10, R11 of the capacitor C7 via the lamp filaments LE means that the circuit cannot attempt to start if the lamp filaments LE1, LEZ are defective.
  • the functionality of the heating filaments is automatically checked when the lamp is started up, so that the circuit arrangement according to the invention can only start operation with an intact fluorescent lamp LL.
  • a ballast for operating low-pressure discharge lamps of low power is created by the circuit arrangement according to the invention. This is advantageous because, for. B. the currently valid regulations in Germany allow the operation of electronic ballasts up to an input power of 25 W without a separate circuit for harmonic reduction is necessary.

Landscapes

  • Circuit Arrangements For Discharge Lamps (AREA)
EP93106095A 1993-04-15 1993-04-15 Ballast électronique Withdrawn EP0620700A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP93106095A EP0620700A1 (fr) 1993-04-15 1993-04-15 Ballast électronique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP93106095A EP0620700A1 (fr) 1993-04-15 1993-04-15 Ballast électronique

Publications (1)

Publication Number Publication Date
EP0620700A1 true EP0620700A1 (fr) 1994-10-19

Family

ID=8212815

Family Applications (1)

Application Number Title Priority Date Filing Date
EP93106095A Withdrawn EP0620700A1 (fr) 1993-04-15 1993-04-15 Ballast électronique

Country Status (1)

Country Link
EP (1) EP0620700A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3303374A1 (de) * 1983-02-02 1984-08-02 Rheintechnik Weiland & Kaspar Kg, 6680 Neunkirchen Stromversorgungsschaltung fuer leuchtstoffroehren
EP0198632A2 (fr) * 1985-04-04 1986-10-22 Chwee Tor Lee Ballast électronique pour lampe fluorescente
WO1988009108A1 (fr) * 1987-05-07 1988-11-17 Robert Bosch Gmbh Circuit pour faire fonctionner une lampe luminescente a gaz sur une source de courant continu
WO1989008971A1 (fr) * 1988-03-18 1989-09-21 Stylux Gesellschaft Für Lichtelektronik M.B.H. Circuit de controle du facteur de service de transistors
EP0439240A2 (fr) * 1990-01-20 1991-07-31 SEMPERLUX GmbH, LICHTTECHNISCHES WERK Ballast électronique

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3303374A1 (de) * 1983-02-02 1984-08-02 Rheintechnik Weiland & Kaspar Kg, 6680 Neunkirchen Stromversorgungsschaltung fuer leuchtstoffroehren
EP0198632A2 (fr) * 1985-04-04 1986-10-22 Chwee Tor Lee Ballast électronique pour lampe fluorescente
WO1988009108A1 (fr) * 1987-05-07 1988-11-17 Robert Bosch Gmbh Circuit pour faire fonctionner une lampe luminescente a gaz sur une source de courant continu
WO1989008971A1 (fr) * 1988-03-18 1989-09-21 Stylux Gesellschaft Für Lichtelektronik M.B.H. Circuit de controle du facteur de service de transistors
EP0439240A2 (fr) * 1990-01-20 1991-07-31 SEMPERLUX GmbH, LICHTTECHNISCHES WERK Ballast électronique

Similar Documents

Publication Publication Date Title
EP0338109B1 (fr) Convertisseur pour lampe à décharge
DE60125214T2 (de) Ballaststeuer-ic mit leistungsfaktorkorrektur
EP0306086B1 (fr) Dispositif de circuit pour le fonctionnement de lampe de décharge à gaz sous haute pression
DE10392956T5 (de) Einzelchip-Ballast-Steuerung mit Leistungsfaktor-Korrektur
EP0359860A1 (fr) Dispositif et procédé de mise en oeuvre d'au moins une lampe à décharge
EP0490330A1 (fr) Circuit de commande de lampes à décharge
EP0679046A1 (fr) Circuit pour alimenter des lampes à décharge basse-pression
EP0264765A2 (fr) Disposition de circuit pour la mise en oeuvre de lampe à incandescence halogène basse tension
DE3608615A1 (de) Schaltungsanordnung zum betrieb von niederdruckentladungslampen
EP0800335A2 (fr) Circuit pour alimenter des lampes électriques
EP0522266A1 (fr) Ballast protégé contre surtension
DE3829388A1 (de) Schaltungsanordnung zum betrieb einer last
EP0439240B1 (fr) Ballast électronique
EP1033066A1 (fr) Circuit pour actionner au moins une lampe a decharge
DE19708791A1 (de) Steuerschaltung und elektronisches Vorschaltgerät mit einer derartigen Steuerschaltung
EP0655880A1 (fr) Circuit basse tension pour l'alimentation d'une lampe à décharge basse pression
EP0753987A1 (fr) Circuit et procédé d'opération de lampes électriques
AT397326B (de) Schaltungsanordnung für die zündung und den betrieb von gasentladungslampen
EP0389847B1 (fr) Circuit
EP1061779B1 (fr) Ballast électronique et procédé pour alimenter une ou plusieurs lampes fluorescentes
EP0620700A1 (fr) Ballast électronique
EP0212740A2 (fr) Disposition de circuit pour le démarrage et le fonctionnement de lampes à décharge gazeuse
DE3626209A1 (de) Vorschaltgeraet fuer wenigstens eine entladungslampe
EP1028606A2 (fr) Circuit pour alimenter au moins une lampe à décharge à basse pression
EP0155729B1 (fr) Circuit pour l'exploitation à courant alternatif pour lampes à décharge à haute pression

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19930922

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE ES FR GB IT NL SE

17Q First examination report despatched

Effective date: 19950619

18D Application deemed to be withdrawn

Effective date: 19951230