Ignition Device

• US 20080174252A1
• Filed: 08/03/2005
• Published: 07/24/2008
• Est. Priority Date: 09/22/2004
• Status: Active Grant

• Current Assignee: Bag Electronics GmbH (Ams-Osram AG)
• Original Assignee: Bag Electronics GmbH (Ams-Osram AG)
• Inventors: Schauerte, Reinhard, Schulte, Tobias, Mertens, Ferdinand
• Granted Patent: US 8,080,944 B2
• Time in Patent Office: Days
• US Class Current: 315/290
• CPC Class Codes: H05B 41/042 using semiconductor devices
• CPC Class Codes: H05B 41/2881 Load circuits; Control thereof
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

In order further to improve the ignition of gas-discharge lamps, in particular high-pressure gas discharge lamps, there is proposed an ignition circuit arrangement for a discharge lamp, with which there is associated a supply circuit for providing an ac supply voltage to the lamp. The ignition circuit arrangement according to the invention (1) includes an ignition transformer (20) which is connected to a trigger circuit (2) on the primary side and to the lamp (3) on the secondary side for transmitting an ignition pulse; an input energy source (30) for the ignition trigger circuit; a first switch means (40) in the trigger circuit and a control means which actuates the first switch means. The ignition circuit arrangement according to the invention is distinguished in that to assist with the ignition process an energy storage means (10) controllable by the control means, in particular a voltage source controllable by the control means, is arranged in the supply circuit in series with the gas-discharge lamp (3). In that case the controllable energy storage means serves to provide an additional energy supply during the ignition process beyond the actual ac supply for the lamp. In addition the invention concerns a method of igniting a gas-discharge lamp.

Claims

1. An ignition circuit arrangement for the ignition of a gas-discharge lamp, in particular a high-pressure gas-discharge lamp, with which there is associated a supply circuit for providing an ac supply voltage (U_N) to the lamp, comprising:

an ignition transformer having a primary side and a secondary side, a trigger circuit electrically coupled to the primary side, the lamp electrically coupled to the secondary side, said ignition transformer configured to transmit an ignition pulse;

an input energy source for the ignition trigger circuit;

a first switch in the trigger circuit, and;

controller configured to control the first switch, said controller is further configured to control a voltage source in series with the lamp to assist in the ignition process of the lamp.

2. An ignition circuit arrangement according to claim 1, further comprising a circuit for detecting the instantaneous value of the supply voltage, wherein the first switch is actuated by the controller within a time interval for opening and closing within at least one half-wave of the supply voltage after a predetermined instantaneous value of the supply voltage is exceeded.

3. An ignition circuit arrangement according to claim 2, wherein the actuation frequency for the first switch varies within the time interval, and wherein the actuation frequency is greater than 290 kHz.

4. An ignition circuit arrangement according to claim 1, further comprising a current path which by-passes the gas-discharge lamp for charging the voltage source, said current path comprises a second switch controlled by the controller.

5. An ignition circuit arrangement according to claim 1, wherein said voltage source comprises an energy storage means, said energy storage means comprises a choke.

6. An ignition circuit arrangement according to claim 1, wherein the input energy source for the ignition trigger circuit include said voltage source and is variably adjustable by the controller.

7. An ignition circuit arrangement according to claim 5, further comprising a circuit for detecting the charging current and/or the charging voltage of the energy storage means.

8. An ignition circuit arrangement according to claim 3, wherein the actuation frequency of the first switch varies within the time interval from a predetermined lower frequency in the direction towards higher frequencies.

9. An ignition circuit arrangement according to claim 8, wherein the actuation frequency of the first switch increases within the time interval to a predetermined upper frequency.

10. An ignition circuit arrangement according to claim 3, wherein the actuation frequency of the first switch changes continuously within the time interval.

11. An ignition circuit arrangement according to claim 9, wherein the time interval is established by the period of time between the moment of reaching the predetermined value and the moment of reaching a predetermined limit value, in particular the peak voltage of the supply voltage.

12. An ignition circuit arrangement according to claim 2, wherein the actuation frequency of the first switch is between 290 kHz and 700 kHz or between 800 kHz and 5 MHz.

13. A method of igniting a gas-discharge lamp, in particular a high-pressure gas-discharge lamp, which in operation is supplied with electrical energy by means of an ac supply circuit, said method comprising:

generating at least one ignition pulse by means of an ignition circuit arrangement having an ignition transformer charging a controllable energy storage means coupled in series with the gas discharge lamp, to assist with the ignition process prior to the production of the at least one ignition pulse; and

superimposing at least a part of the energy stored in the controllable energy storage means on the ac supply of the lamp in the ignition process.

14. A method according to claim 13, wherein a single ignition pulse is produced within a half-wave of the supply voltage.

15. A method according to claim 13, wherein after the production of at least one ignition pulse within a half-wave of the supply voltage at least one further ignition pulse is produced within a subsequent half-wave upon the attainment of a predetermined instantaneous value of the supply voltage.

16. A method according to claim 15, wherein the input voltage of a trigger circuit for the production of the at least one ignition pulse is adjusted to be less in the subsequent half-wave in comparison with the input voltage for the production of the at least one ignition pulse in the preceding half-wave.

17. A method according to claim 13 wherein a charging current path is connected for charging the chargeable energy storage means prior to the production of the at least one ignition pulse, which charging current path is interrupted prior to the production of the first ignition pulse.

18. A method according to claim 17, wherein a capacitor arranged in parallel with the lamp is charged up after the termination of the charging of the energy storage means and prior to the production of the at least one ignition pulse by opening of the charging current path.

19. A method according to claim 13, wherein the charging current and/or the instantaneous voltage of the energy storage means is detected.

20. A method according to claim 19, wherein the input voltage of an ignition trigger circuit for producing the at least one ignition pulse is controlled in response to the detection of the charging current and/or to the detection of the instantaneous voltage of the energy storage means.