Electronic ballast having timing unit correction

• US 20050174067A1
• Filed: 02/01/2005
• Published: 08/11/2005
• Est. Priority Date: 02/06/2004
• Status: Active Grant

• Current Assignee: Optotronic GmbH (Inventronics (Hangzhou), Inc.)
• Original Assignee: Patent-Treuhand-Gesellschaft Fur Elektrische Gluhlampen mbH (Ams-Osram AG)
• Inventors: Norali-Ghasemi, Shokrollah, Huber, Andreas, Pilz, Axel, Langgassner, Wolfgang
• Granted Patent: US 7,193,371 B2
• Time in Patent Office: Days
• US Class Current: 315/291
• CPC Class Codes: H05B 41/2828 using control circuits for the switching elements H05B41/2827 takes precedence
• CPC Class Codes: H05B 47/18 via data-bus transmission

Abstract

The invention relates to an operating method and an electronic ballast (EVG) for operating a light-producing apparatus (L), for example a discharge lamp. In this case, an internal timing unit in the ballast (EVG) is corrected with the aid of time information (TM) received in external signals.

Claims

1. A method for operating a light-producing apparatus, in which

the light-producing apparatus is operated using an electronic ballast which has an internal timing unit for internal timing purposes,

an external signal, which contains time information, is received by the electronic ballast,

the internal timing is corrected with the aid of the time information, and

operating functions of the light-producing apparatus are controlled with the aid of the timing.

2. The method as claimed in claim 1, in which the correction of the timing takes place by calculating and storing a correction value whilst an oscillator itself, contained in the internal timing unit, remains unchanged.

3. The method as claimed in claim 1, in which the external signal is a digital control signal of a control device driving the electronic ballast in an illumination system.

4. The method as claimed in claim 3, in which the time information is determined from the data rate of the digital control signal.

5. The method as claimed in claim 4, in which the time information is determined from the time interval between the first pulse edges of the digital control signal.

6. The method as claimed in claim 5, in which the time information is determined from the interval between the first two equidirectional pulse edges of the digital control signal, and a correction factor is taken into account depending on the bit value associated with the pulse edges.

7. The method as claimed in claim 1, in which the external signal is supplied by a sensor.

8. The method as claimed in claim 7, in which the sensor is a light value sensor which detects the brightness of a region which is illuminated or is to be illuminated by the light-producing apparatus.

9. The method as claimed in claim 7, in which the external signal is frequency-encoded.

10. The method as claimed in claim 7, in which the sensor is a movement sensor whose signal leads to the light-producing apparatus being switched on.

11. The method as claimed in claim 7, in which the external signal is duration-encoded.

12. The method as claimed in claim 1, in which the electronic ballast can be dimmed by means of duration-encoded supply voltage pulses at a control input.

13. The method as claimed in claim 12, in which short supply voltage pulses are switch-on and switch-off commands.

14. The method as claimed in claim 1, in which the internal timing unit has an RC oscillator.

15. The method as claimed in claim 1, in which the light-producing apparatus is a lamp, in particular a discharge lamp.

16. An electronic ballast which is designed for the method as claimed in one of the preceding claims and has an internal timing unit for controlling operating functions of the light-producing apparatus,

and a time correction device which is designed to carry out, once an external signal having time information has been received, a correction of the timing of the internal timing unit using the time information.