EP1562408A1 - Electronic ballast with timer-based correction - Google Patents

Abstract

The method involves operating the light generating device with an electronic voltage adapter with an internal time generator and receiving an external signal from the electronic voltage adapter that contains time information (TM), correcting the internal time generation using the time information and controlling operating functions of the light generating device with the aid of the time generation.. An independent claim is also included for an electronic voltage adapter for implementing the inventive method.

Description

Technical area

The present invention relates to a method for operating a Light-generating device, in particular a lamp.

State of the art

It is known per se for the operation of lamps, in particular discharge lamps, or other light-producing devices such as LEDs electronic Use ballasts. This term means electronic Operating devices of various shapes and in particular those with about an inverter from a supply voltage of the ballast one in terms of voltage, frequency and / or other relevant quantities produce adapted supply voltage for the light-generating device. An important application is electronic ballasts with inverters, the discharge lamps, especially, but not exclusively, Low-pressure discharge lamps operate. Such electronic Ballasts are in many cases equipped with controls that have a require internal ballast timer. From the signal of the internal Timer can in particular the operating frequency of a discharge lamp be derived.

Presentation of the invention

The invention is based on the technical problem, an improved operating method and to provide an improved electronic ballast where an internal timer is used.

The invention is directed to a method of operating a light-generating device in which the light-generating device is operated with an electronic ballast having an internal timer for an internal timing, an external signal is received from the electronic ballast containing time information the internal timing is corrected with the aid of the time information and operating functions of the light-generating device are controlled by means of the timing,
and to a correspondingly configured electronic ballast having an internal timer for controlling operation functions of the light-generating device and a time correction device.

Preferred embodiments of the invention are defined in the dependent claims and are explained below. It is between the method character and the device character of the invention not more in detail. The features are each for both aspects of the invention substantially and as disclosed for both categories of claims to watch.

The invention assumes the internal timing of the ballast using time information to correct that in an outer signal were received. This is based on the observation of the inventors that it with a combination of electronic ballasts with others technical equipment, such as other ballasts or sensors or Controllers, problems with inaccurate internal timers come can. This applies, for example, to the evaluation of signals relative to one Reference time or reference frequency, the timed operation of a Multiple ballasts with each other and other situations.

But instead of the internal timer of the ballast by a central Timers replace the timing within the ballast So in principle to make by external signals, beat the Inventors intend to continue to work with an internal timer, but corrections perform. This keeps the ballast a certain Self-employment and can also be operated completely independently of other devices become. On the other hand, there is no need for use technically and financially complex accurate timers, such as Quartz or ceramic oscillators, or an elaborate customization of oscillators in the manufacture to avoid component scattering. However, such accuracy-promoting measures are in the invention not excluded. Rather, the invention merely allows such measures to leave out in individual cases, because they have a lower dependence on the accuracy of the internal timer.

A correction is preferred by calculating and storing a correction value. It should be the oscillator on which the internal timer is based on continue to run unchanged. Of course, the invention also includes solutions where this oscillator changes, so readjusted or tuned becomes. However, the mentioned preferred solution with correction values is in many Cases more pragmatic and simple and equally effective.

The outer signal may be a control signal, preferably a digital one Be control signal with which a control unit, the electronic ballast as part of a lighting system controls. Be considered in particular also control signals according to the so-called DALI protocol, but also digital control signals of other communication protocols.

The time information may be digitally encoded in such digital control signals However, it is preferably included in the digital data rate, ie Bit frequency or comparable sizes. Preferably, the time information becomes determined by the time interval of pulse edges, and especially preferably from first pulse edges of a digital word (Bytes). For example, the time information may be separated by the time interval of the first same-minded, ie the first falling or the first rising, flanks of a byte. First flanks can of course be the first opposing flanks. In some cases, depending on the value the one or more associated with these edges bits a correction must be considered, because the time interval from the bit value can depend. It is on the embodiment and the local correction referenced with the factor 1.5.

The outer signal, in which the time information is contained, can also from come from a sensor. It can also be a digital signal and also to act as a digital signal within the DALI protocol. It But also analog signals come into consideration. In particular, come here also applications outside of control units controlled by lighting devices in consideration, such as when single or a small number of ballasts communicate with a sensor without lighting a lighting system to form a common control. Of the In particular, the sensor can be a light value sensor which is the ballast Information about the brightness of a light to be lit or illuminated Area supplies. In this case, the ballast can be designed so that it by means of an automatic dimming function dependent on that of the sensor supplied light information controls the lamp brightness or regulates.

Preferably, there is one in the outer signal provided by the sensor Frequency coding, for example, expresses the information about the light value by the frequency of the signal or a frequency within of the signal.

The sensor may instead of a light value sensor or in addition to a Light value sensor can also be a motion detector whose signal and turning off the light-generating device, in particular one Lamp, serves.

Furthermore, in the sensor signal in addition to the frequency coding or instead of the frequency coding, a time duration coding in the sense of coding exist over the duration of certain signal parts or pulse trains. Especially preferred is a combination of light value sensor and motion detector, in the light value information with a frequency coding and in contrast motion detection signals with a fixed one Frequency, but a certain minimum time duration transmitted become. Reference is made to the embodiment.

It has already been mentioned that the electronic ballast preferably has a dimming function, such as a via a light sensor signal automatically operable dimming function. In the invention is also preferred that the dimming function via a control input of the electronic ballast is controllable, in particular on the creation of Supply voltage pulses to the control input. It is preferred that relatively short pulses (in a time-length coding) are on and off commands mean and relatively longer pulses depending on their length dimming commands mean.

In the various mentioned codes, so the frequency coding or time-coding, the signals of the internal timer to the Evaluation used and the invention by correction an improvement cause the described functions. This correction can also be done by the timer signals unchanged for evaluation or control, but in the for this evaluation or control circuit parts of the electronic ballast responsible the corresponding correction values only at the evaluation or Control itself be taken into account. So it can be embodiments where the oscillator signal itself or derived from it purely temporal signals are not corrected but the correction only at the Application of temporal information for control or evaluation made becomes. The term "timing" is not in this sense as on the Oscillator and any subsequent timer limited but to see Also includes the components in which the temporal information for Evaluation or control is used. However, a correction is preferred of the timer (including derived timer).

Since the invention proposes correction possibilities, it is preferable to simple and inexpensive internal timers, so in particular those which contain simple RC oscillators. These can also be on-chip oscillators, So in a control circuit, such as a microcontroller, act integrated oscillators.

Brief description of the drawings

The invention will be described in more detail below with reference to an exemplary embodiment explained, wherein the individual features essential to the invention in other combinations could be.

Figur 1

ein schematisches Diagramm einer Beleuchtungsanlage mit einem erfindungsgemäßen Vorschaltgerät.

Figur 2

ein schematisches Diagramm eines mit einem Sensor eingesetzten erfindungsgemäßen Vorschaltgeräts.

Figur 3

eine schematische Darstellung von digitalen Signalen in der Beleuchtungsanlage aus Figur 1.

Figur 4

ein Flussdiagramm zur Erläuterung des Ablaufs des erfindungsgemäßen Verfahrens in dem Vorschaltgerät aus Figur 1.

Figur 5

eine schematische Darstellung eines Signals des Sensors aus Figur 2.

Figur 6

ein Flussdiagramm zur Erläuterung des erfindungsgemäßen Verfahrens in dem Vorschaltgerät aus Figur 2.

In detail shows:

FIG. 1

a schematic diagram of a lighting system with a ballast according to the invention.

FIG. 2

a schematic diagram of a ballast used with a sensor according to the invention.

FIG. 3

a schematic representation of digital signals in the lighting system of Figure 1.

FIG. 4

a flowchart for explaining the sequence of the method according to the invention in the ballast of Figure 1.

FIG. 5

a schematic representation of a signal of the sensor of Figure 2.

FIG. 6

a flowchart for explaining the method according to the invention in the ballast of Figure 2.

Preferred embodiment of the invention

Figure 1 shows schematically one of a variety of electronic ballasts and connected lamps as well as partially u. U. also without Ballasts powered lamps and sensors existing lighting system. In it is with SG a central digital control unit and with ECG one of the ballasts referred to, which is an inventive Ballast is. One of the electronic ballast ECG operated low-pressure discharge lamp is denoted by L. The remaining outgoing from the control unit SG lines are the Symbolize variety of other elements of the lighting system.

The control unit SG controls the electronic ballast according to the DALI protocol constructed digital control signals, in Figure 3 schematically are shown. There is always the beginning of a first upper and one second lower signal shown. These are so-called biphase coded Signals. This means that the logical 1 and the logical 0 do not correspond to the electrical low or high level or vice versa but correspond a predetermined level change. For example, an ascending means Level jump a logical 0 and a falling level jump one logical 1. This has the advantage that the presence of a bit is unique can be recognized. For reference, reference is made to the EP 1 069 690.

FIG. 3 shows the beginning of a word (frame), where a left first Start bit with rising edge, so logical 0, is located. It follows a most significant bit # 15 and other bits with the numbers 14-0, of which only the bit no. 14 is drawn. Already the bit number 15 can be different Take values as the two superimposed Word beginnings in Figure 3 illustrate.

The electronic ballast uses the time interval of the first two falling edges, which is denoted by T _M in the figure, as time information.

It can be seen that this time interval in the lower case one and a half times as long as in the upper case and the upper time interval of the bit rate equivalent.

FIG. 4 illustrates, within the scope of a flow chart, the functional sequence within the ballast EVG from FIG. 1. The determined time T _M is received via two signal paths, one of which provides for a multiplication by a factor of 1.5. Depending on the value of the most significant bit (MSB) no. 15, a switch is made between these two signal paths, so that in each case there is the 1.5-fold bit rate behind the symbolic switch labeled MSB. The time T _M is measured by means of the ballast's internal timer and therefore carries its error. The 1.5-fold bit rate is compared with a nominal data rate stored in the ballast EVG, from which a correction value is calculated. The right-hand portion of FIG. 4 illustrates that this correction value may alternatively be applied to the oscillator of the timer itself to adjust it or to be supplied to the internal timers of the timer supplied by the oscillator. In the embodiment, the lower variant is performed, ie that the oscillator in the ballast ECG continues uncorrected. In both cases, the bit rate serves as the time reference of the ECG's internal timing.

A second example is shown in Figure 2. There is the same ballast electronic ballast as used in Figure 1 in a different way. It is an assignment in a single luminaire with a lamp L and a light sensor S. The Ballast ECG is, as symbolically shown below, with a supply voltage supplied, about the usual household voltage. This is via a button T another control input of the ballast ECG supplied.

The light sensor S has both a function as a light value sensor for detection the brightness of a room illuminated by the lamp L as well the function of a motion detector for detecting movements in this room. When the light is always on, switch the ballast EVG the lamp L depending on whether or not a Movement in the space is detected and reported by the light sensor S. or if no movement is reported for an adjustable time, say 15 minutes has been. This can be achieved on the one hand, that the light itself turns on when the room is entered by a person and on the other hand avoiding that the lamp is operated unnecessarily and thus Energy consumed when the room is not used.

In addition, the light sensor S detects the brightness of the illuminated Room, depending on the use of other lights or even dependent may vary from daylight exposure. This can be a dimming function of the electronic ballast automatically the power of the lamp L adjust, so in particular the lamp power back, if in In the morning the daylight radiation increases, and start again, if during the late afternoon and evening the daylight radiation decreases.

In addition, via the button T of the mentioned control input of the ballast ECGs are used. A short touch means a manual one On or Off command. A longer touch leaves the ballast ECG the lamp L cyclically high and after reaching the maximum Power down again and after reaching the minimum dimming power Dimming up again. Thus the user can hold by holding manually set a desired lamp power of the T button, which then depending on the further light value information from the light sensor S is readjusted.

FIG. 5 shows schematically a signal transmitted by the light sensor S to the ballast EVG over the time axis. The individual blocks, as shown in the section in the upper area, stand for a respective sequence of individual pulses. At the same time there is an encoding over the duration as well as the frequency of the signals. The relatively short blocks are transmitted at constant intervals and form a reference signal within the meaning of the time correction as a result of the respectively present pulse frequency within the blocks. Thus, the same standard time duration T _{M is} tapped off as explained with reference to FIGS. 3 and 4, and, however, without distinction between different bit states, used in the same way as explained with reference to FIG. 4 for the correction. This is shown in FIG.

The light sensor S interrupts this sequence of regular reference signals then, when he has sensed a movement, by a motion signal. This signal is shown in the middle in FIG. 5 and differentiates away from the reference signals in that it has a specific Minimum duration. A motion signal leads, as already explained, for switching on or maintaining the operation of the lamp L.

Between the already explained reference signal blocks are slightly longer continuous light value signal blocks are drawn, which in principle like the motion signal are constructed. However, they have a different one Frequency up. The difference of the frequency of the light value signals from the set frequency of the reference signals and motion signals represents the detected light value and leads in the ballast ECG to a here Not shown in detail evaluation and control of the dimming function.

With the help of the invention can in the electronic ballast electronic ballast simple on-chip RC oscillator can be used without leaving its Inaccuracy disadvantages grown up. In particular, in the lighting system according to Figure 1 avoided that the scattering between different Oscillators in different electronic ballasts leads to functional deviations. If, for example, by a certain DALI command a parallel dimming of different lamps via a uniform time is performed, typical tolerances of about ± 4%, for example, to deviations between a dimming time of 16.6 s in one ballast and 15.4 s in another. These Difference of 1.2 s is clearly visible and disturbs the actually intended Parallelism of the dimming processes. The same is true of course by temporal shifts, Temperature drift and the like occurring deviations.

In the application according to FIG. 2, in turn, besides the above Explanation corresponding inaccuracies control problems result. For example, if a thermal drift of the oscillator in the Ballast electronic ballast with its increasing warming during operation to a Change of the reference frequency for the evaluation of the light value information leads, the ballast ECG in response to the Activate dimming function. The temperature drift of the oscillator frequency would thus without the invention to a change in the total light intensity in the room or lead to a temperature drift caused drift of the lamp power. If several ballasts were provided in the room, would be in Result of the now drifting total light intensity in the room other ballasts in turn, readjust, leaving an overall unstable control situation could arise.

Claims (16)

Method for operating a light-generating device (L), in which
the light-generating device (L) is operated with an electronic ballast (ECG) having an internal timer for an internal timing,
an external signal is received from the electronic ballast (ECG) containing timing information (T _M ),
the internal timing is corrected using the time information (T _M ) and
Operating functions of the light-generating device (L) are controlled by means of the timing. The method of claim 1, wherein the correction of the timing by calculating and storing a correction value if left unchanged an oscillator included in the internal timer even done. Method according to Claim 1 or 2, in which the external signal is a digital signal Control signal of the electronic ballast (EVG) in one Lighting system driving control unit (SG) is. Method according to Claim 3, in which the time information (T _M ) is determined from the data rate of the digital control signal. Method according to Claim 4, in which the time information (T _M ) is determined from the time interval between first pulse edges of the digital control signal. Method according to Claim 5, in which the time information (T _M ) is determined from the distance between the first two equidirectional pulse edges of the digital control signal and a correction factor is taken into account as a function of the bit value connected to the pulse edges. Method according to one of the preceding claims, wherein the outer Signal from a sensor (S) is supplied. Method according to Claim 7, in which the sensor (S) is a light value sensor is the brightness of a light-generating device (L) illuminated or illuminated area detected. A method according to claim 7 or 8, wherein the external signal is frequency encoded is. The method of claim 7, 8 or 9, wherein the sensor (S) is a motion detector is whose signal to turn on the light-generating Device (L) leads. Method according to one of claims 7 - 10, wherein the external signal is time-coded. Method according to one of the preceding claims, wherein the electronic Ballast (ECG) via time-duration-coded supply voltage pulses is dimmable at a control input. The method of claim 12, wherein short supply voltage pulses On and Off commands are. Method according to one of the preceding claims, in which the internal Timer has an RC oscillator. Method according to one of the preceding claims, in which the light generating device (L) a lamp, in particular a discharge lamp is. Electronic ballast (ECG) adapted for a method according to one of the preceding claims, and comprising
an internal timer for controlling operation functions of the light-generating device (L),
to perform and a time correction device which is adapted to receive an external signal with time information (T _M) a correction of the timing of the internal timer by the time information (T _M).

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