EP1225791A2 - Verfahren und Anordnung zum Betreiben einer Nieder-Druck Entladungslampe mit hochfrequentem Wechselstrom - Google Patents

Verfahren und Anordnung zum Betreiben einer Nieder-Druck Entladungslampe mit hochfrequentem Wechselstrom Download PDF

Info

Publication number
EP1225791A2
EP1225791A2 EP01660253A EP01660253A EP1225791A2 EP 1225791 A2 EP1225791 A2 EP 1225791A2 EP 01660253 A EP01660253 A EP 01660253A EP 01660253 A EP01660253 A EP 01660253A EP 1225791 A2 EP1225791 A2 EP 1225791A2
Authority
EP
European Patent Office
Prior art keywords
lamp
capacitor
bridge inverter
inductor
frequency
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Withdrawn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
EP01660253A
Other languages
English (en)
French (fr)
Other versions
EP1225791A3 (de
Inventor
Hannu Vihinen
Harri Naakka
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.)
Helvar Oy AB
Original Assignee
Helvar Oy AB
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 Helvar Oy AB filed Critical Helvar Oy AB
Publication of EP1225791A2 publication Critical patent/EP1225791A2/de
Publication of EP1225791A3 publication Critical patent/EP1225791A3/de
Withdrawn legal-status Critical Current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
    • H05B41/282—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
    • H05B41/2828—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 control circuits for the switching elements

Definitions

  • the present invention relates to a method for supplying high-frequency alternating current to a low-pressure discharge lamp, in which method the lamp drive current is passed from the common point of the switches of a totem-pole half-bridge inverter via an inductor connected in series with the lamp to a capacitor having so large a capacitance that permits the capacitor to act at DC voltage essentially as a power source.
  • the invention also relates to an electronic ballast for supplying high-frequency alternating current to a low-pressure discharge lamp, the ballast comprising a totem-pole half-bridge inverter and a lamp circuit connected to the common point of the inverter switches, the lamp circuit being comprised of a series configuration formed by an inductor, the lamp and a capacitor, the latter having such a large capacity that permits the same to act at DC voltage essentially as a power source, and of a second capacitor connected in parallel with the series connection of the lamp and the DC blocking capacitor.
  • the resonant frequency of the inductor with the second capacitor is utilized for heating the lamp cathodes prior to the ignition of the lamp.
  • the inverter frequency is generally offset from the resonance, typically toward a lower frequency, in order to allow the inductor to pass a sufficiently large lamp drive current.
  • the frequency control has been utilized to realize a lamp intensity control facility.
  • ballasts must be separately dimensioned and adapted for different lamp types operating at different input power levels. Recently, a family of four new lamp types has been released to the market with the same nominal current (170 mA) but having different nominal power ratings (14 W, 21 W, 28 W and 35 W).
  • a ballast shown in FIGS. 1 and 2 comprises a half-bridge inverter 1, 2, as well as a lamp circuit connected to the common point V in of the inverter switches 1, 2 and being comprised of a series configuration formed by an inductor L, a lamp 4 and a capacitor 5, the latter having such a large capacitance that permits the same to act at DC voltage essentially as a power source.
  • a second capacitor C is connected in parallel with the series connection of the lamp 4 and the DC blocking capacitor 5.
  • Reference numeral 8 denotes a DC source feeding the ballast circuit at 410 VDC, for instance.
  • the operating frequency of the half-bridge inverter 1, 2 is controlled with the help of an oscillator incorporated in control means 3 to stay tuned to the resonant frequency of the oscillatory circuit formed by inductor L and second capacitor C.
  • inductor L and second capacitor C are dimensioned so that at the resonant frequency of resonant circuit components L, C, the inverter delivers the desired lamp current (e.g., 170 mA) at a constant level that is substantially independent of the resistance (denoted by resistance R in FIG. 3) of lamp 4.
  • the circuit practically functions as a constant-current generator, whose output current is not dependent on the resistance R of load 4. Since this matter is by no means obvious and can be realized only at a predetermined resonant frequency for a predetermined inverter output current, the behavior of a resonant circuit delivering a constant current needs a theoretical treatise given below.
  • V in denotes the average common-point voltage of the totem-pole half-bridge. Since a sinusoidal voltage is easiest to deal with mathematically, the formulas are written for the first harmonic of the common-point voltage waveform only. Typically, the peak-to-peak output voltage of the ballast inverter in the applicant's ballast constructions is about 410 V.
  • the peak value of the input voltage V in to the circuit is only half of the peak output voltage 2 ⁇ V in of the ballast inverter inasmuch DC blocking capacitor 5 is omitted from the equivalent circuit. This is permissible because the role of the DC blocking capacitor in the present treatise is relatively insignificant.
  • the lamp circuit inductor is denoted by reference letter L, while reference letter C denotes the starting capacitor.
  • Resistor R denotes the resistance of the lamp at its operating point.
  • Eq. 2 makes it possible to find such circuit parameters that make the lamp drive current independent from the load resistance (which in the equivalent circuit is resistance R that represents the lamp).
  • ⁇ is angular frequency
  • Eqs. 7 and 8 solve as 3.05 nF for the starting capacitor and 3.6 mH for the lamp inductor. Since the capacitance value is rather nonstandard, the equations are solved the other way around by asking: what frequency and inductance values allow the use of standard 3.3 nF capacitor. As a result, the proper frequency appears to be 44.4 kHz and the inductor must be 3.887 mH.
  • FIG. 5 is plotted a family of curves representing the lamp drive current as a function of frequency at different lamp resistances. It can be seen that the curves meet each other at the desired lamp current of 170 mA.
  • control means 3 include current sensing means 6, 3 for measuring the current passing through switch 2 of the half-bridge inverter. Based on these, the control means 3 can elevate the operating frequency of the half-bridge inverter 1, 2 substantially above the resonant frequency of the circuit formed by components L, C in the case that the sensed current, particularly the peak value thereof, tends to exceed or fall below the predetermined limit values. This precaution serves e.g., to prevent the voltage and current of the resonant circuit L, C from growing excessively high after lamp 4 is ignited.
  • Reference numeral 7 denotes a facility of measuring the phase shift between the lamp circuit current and voltage. Such a measurement gives an option to verify that the lamp circuit is operating at its resonant frequency.
  • the measurement facility 7 can be utilized, in addition to monitoring circuit operation at the constant resonant frequency programmed in the control means 3, as an alternative method for determining the operating frequency, whereby control means 3 need not have to be preprogrammed for a constant resonant frequency.
  • ballast is also suited for use in two-lamp configurations where the power ratings of lamps adapted in a single lighting fixture may be different from each other (e.g., one 14 W lamp and one 35 W lamp in combination).
  • the power ratings of lamps adapted in a single lighting fixture may be different from each other (e.g., one 14 W lamp and one 35 W lamp in combination).
  • a greater freedom is gained in the design of illumination distribution.

Landscapes

  • Circuit Arrangements For Discharge Lamps (AREA)
EP01660253A 2001-01-05 2001-12-28 Verfahren und Anordnung zum Betreiben einer Nieder-Druck Entladungslampe mit hochfrequentem Wechselstrom Withdrawn EP1225791A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI20010016A FI109572B (fi) 2001-01-05 2001-01-05 Menetelmä ja laite suurtaajuusvaihtovirran syöttämiseksi pienpaineiselle purkauslampulle
FI20010016 2001-01-05

Publications (2)

Publication Number Publication Date
EP1225791A2 true EP1225791A2 (de) 2002-07-24
EP1225791A3 EP1225791A3 (de) 2004-08-11

Family

ID=8559885

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01660253A Withdrawn EP1225791A3 (de) 2001-01-05 2001-12-28 Verfahren und Anordnung zum Betreiben einer Nieder-Druck Entladungslampe mit hochfrequentem Wechselstrom

Country Status (2)

Country Link
EP (1) EP1225791A3 (de)
FI (1) FI109572B (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7982405B2 (en) 2005-03-22 2011-07-19 Lightech Electronic Industries Ltd. Igniter circuit for an HID lamp

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
YIYOUNG SUN: "Improved simulation accuracy and reduced design time for electronic ballast designs which incorporate fixed frequency controller ICs" INDUSTRY APPLICATIONS CONFERENCE, 1996. THIRTY-FIRST IAS ANNUAL MEETING, IAS '96., CONFERENCE RECORD OF THE 1996 IEEE SAN DIEGO, CA, USA 6-10 OCT. 1996, NEW YORK, NY, USA,IEEE, US, 6 October 1996 (1996-10-06), pages 2183-2188, XP010201350 ISBN: 0-7803-3544-9 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7982405B2 (en) 2005-03-22 2011-07-19 Lightech Electronic Industries Ltd. Igniter circuit for an HID lamp

Also Published As

Publication number Publication date
FI20010016A0 (fi) 2001-01-05
EP1225791A3 (de) 2004-08-11
FI109572B (fi) 2002-08-30

Similar Documents

Publication Publication Date Title
US6876160B1 (en) Fluorescent ballast with fiber optic and IR control
US4399391A (en) Circuit for starting and operating fluorescent lamps
US5422546A (en) Dimmable parallel-resonant electric ballast
US4712170A (en) Power supply having tuned radio frequency circuit
JPH0317197B2 (de)
CA2104252A1 (en) Lamp ballast circuit
US7923942B1 (en) Constant current source mirror tank dimmable ballast for high impedance lamps
EP1227706A3 (de) Neue Schaltungsentwürfe und Steuerungstechniken für elektronische Hochfrequenz-Vorschaltgeräte für Entladungslampen hoher Intensität
CN1196379C (zh) 通用高强度放电电子起动器
EP1225791A2 (de) Verfahren und Anordnung zum Betreiben einer Nieder-Druck Entladungslampe mit hochfrequentem Wechselstrom
EP1986475B1 (de) Zündschaltung für eine HID-Lampe
US5510681A (en) Operating circuit for gas discharge lamps
EP0840537A1 (de) Vorschaltgerät für eine Hochleistungsentladungslampe
US4608523A (en) Phase correction for series-resonant ballasts
US5013974A (en) Electronic ballast with improved lamp current crest factor
BR0016751A (pt) Lastro eletrônico e transformador eletrônico
US4651271A (en) Power supply having tuned radio frequency circuit
AU777106B2 (en) Ballast for gas discharge lamps with shutdown of the filament heating
Migo et al. Start-up of SSTC semiconductor tesla coil-an example of an educational project
US5004947A (en) Fluorescent lamp ballast with high power factor
US5434481A (en) Electronic ballast for fluorescent lamps
JP2000021594A (ja) 圧電素子を用いた安定器および力率補償回路
CA2456367A1 (en) Circuit arrangement and method for starting and operating gas discharge lamps with heatable electrode filaments
US5270618A (en) Magnetic-electronic dual-frequency ballast
GB2211038A (en) Protective electronic ballast circuit for fluorescent lamps

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

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Extension state: AL LT LV MK RO SI

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20040819