WO2008009307A1

WO2008009307A1 - Lighting system comprising a dimmable ballast

Info

Publication number: WO2008009307A1
Application number: PCT/EP2006/007214
Authority: WO
Inventors: Gotthard Schleicher
Original assignee: Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH
Priority date: 2006-07-21
Filing date: 2006-07-21
Publication date: 2008-01-24

Abstract

The invention relates to a lighting system comprising a dimmer switch which is connected to electronic ballasts via optical signal transmission.

Description

Lighting system with dimmable ballast

Technical area

The present invention relates to dimmable electronic ballasts for lamps. In this case, the term "lighting system" for the electronic ballast is used together with a dimmer switch for its dimming control, wherein the appropriate lamp may be included, but not necessarily. The term "lamp" applies to bulbs in the most general sense including LED and LED modules.

State of the art

It is known to dim electronic ballasts and thus supplied by them lamps via dimmer switch. The dimmable ballasts and lamps can be used for brightness control or adjustment or for "soft" on and off or similar purposes. For this purpose, dimmer switches are electrically connected to a ballast, but are often located away from it.

The invention relates specifically to the latter case that the electronic ballast receives a signal for dimming operations via a dimmer switch separate from the ballast. The signals can thereby define the start of a dimming process and its end or also a dimming process up to a predefined next brightness value, or else give specifications for a dimming process which is otherwise to be performed by the electronic ballast itself. In the prior art are integrated into the power supply of the ballasts Dimming devices, in particular Phasenanschnittsimmer known, which trigger the dimming process by influencing the power supply and thus do not control a dimming process to be performed by the ballast itself.

Presentation of the invention

The invention is based on the technical problem of providing an improved lighting system of this type, which offers improved possibilities of use due to a favorable compromise between reliability and technical complexity.

The invention relates to an illumination system with a dimmable electronic ballast and a dimming switch connected to the ballast for dimming control of the ballast, characterized by an optical signal transmitter connected to the dimmer switch, an optocoupler electrically connected to the ballast and an optical waveguide which optically couples the optical signal transmitter to the optocoupler,

and to a lighting system with a digital control device and such a lighting system with a plurality of digitally controllable ballasts,

and finally to a method for operating a lamp with such an illumination system, in which method a dimming signal is input via a dimmer switch, converted into an optical signal via an optical signal transmitter, transported via an optical waveguide to an optocoupler and through the optocoupler is converted into an electrical signal which is supplied to an electronic ballast and used for dimming control of this ballast, wherein the ballast operates the lamp in response to the dimming control.

Preferred embodiments are specified in the dependent claims and are explained below. The entire revelation is there both with regard to the device character and the method character of the invention, without any explicit distinction between them in detail.

The basic idea of the invention is the use of an optical waveguide between see the dimmer switch and the ballast. The optical waveguide should optically connect an optical signal transmitter connected to the dimmer switch to an optocoupler, which in turn is electrically connected to the ballast. The dimming signal is thus transported after conversion into an optical signal through the optical waveguide to the optocoupler, which in turn can be arranged in the immediate vicinity of the ballast if necessary or preferably even structurally integrated in the ballast.

By eliminating the electrical transmission between the optical signal transmitter and the optocoupler electromagnetic interference and problems with insulation resistance, voltage protection and the like. Avoid. Specifically, the input of the optocoupler, preferably a control input of the ballast, remains voltage isolated and therefore inherently safe. Short circuit risks are largely eliminated.

The optical fiber between the signal transmitter and the optocoupler does not necessarily have to be continuous. In individual cases, it may be of interest to interpose an electrical device, for example for signal amplification during long transmission distances or for signal distribution, mixing or coupling in complex lighting systems. However, it is preferred that the optical waveguide is designed to be continuous, ie a purely optical transmission takes place via optical conductors between the signal transmitter and the optocoupler. Furthermore, this optical waveguide is preferably also in one piece, that is not composed of a plurality of structurally separate parts in order to minimize the structural complexity and the losses.

Furthermore, it is preferable to use optical connector elements which are known per se for the invention, that is to say the optical waveguide at least on the latter - A -

Optocoupler and / or to be mounted on the signal generator by an optical connector element. Since the optocoupler is preferably integrated in the ballast, in this case, of course, results in an optical connector element on the device itself.

The mentioned advantages of avoiding electromagnetic interference in optical transmission are particularly important in applications where relatively large transmission lengths occur. In this sense, the invention is preferably directed to applications with lengths of the optical waveguide of at least 2.5 m.

Some of the mentioned advantages of using optical fibers also exist for additional signaling connections in a lighting system or a larger lighting system. It is therefore preferred that the ballast has an optical output and / or input for data communication via a further or the same optical waveguide.

The dimmer switch is within the scope of the invention preferably a push button or "button". Such buttons are already known per se as a dimmer switch. In conventional solutions, the time duration of the signal is evaluated and represents the desired brightness change.

The optical signal transmitter may be preceded by a filter for filtering the current for generating the optical signal. Of course, the filter does not have to be integrated in the optical signal transmitter. What is essential is that the current used to generate the optical signal be filtered. In order for a low-interference or interference-free light signal can be generated, which allows a particularly clean and undisturbed detection in the optocoupler or the ballast. For example, zero crossings are counted in existing digitally controllable ballasts ("touch-dim") for evaluating a dimming signal. If additional zero crossings occur due to disturbances, this can lead to errors, such as the signal is rejected or misinterpreted. Preferred applications are also in more complex lighting systems or lighting systems in which a plurality of ballasts occur and are preferably connected via a common optical waveguide with a common signal generator and dimmer switch. In this case, the optical waveguide can be divided or multiple present so that it provides the coupled light signal to the optocouplers of the various ballasts. In a further preferred embodiment, the ballasts also share the optocoupler and are electrically connected to a common optocoupler.

In the following, the invention will be explained in more detail with reference to an embodiment, wherein the disclosed individual features may be essential to the invention in other combinations and the following as well as the above description are based on both the device category and the method category of the invention.

Short description of the drawing

FIG. 1 shows a simplified block diagram of a lighting system according to the invention.

Figure 2. shows a block diagram corresponding to Figure 1 to a variant of the illumination system according to the invention as a second embodiment.

Preferred embodiment of the invention

An inventive lighting system according to Figure 1 has three low-pressure discharge lamps LA1, LA2 and LA3, which are each operated by a suitable ballast electronic ballast QT DALI 1, 2 and 3 respectively. These are controllable according to the DALI protocol, so digitally addressable, electronic ballasts of the type "Quicktronic" manufacturer OSRAM. Their connections 1 to 4 are each used for lamp supply, two respective connections DA for digital control by a respective optocoupler OK1, 2 or 3 and further two designated with an AC symbol terminals for connection to a power supply. The power supply shown on the top left has three phases L1, L2 and L3 associated with the respective electronic ballasts, which can be switched separately, as well as a neutral conductor N and a tester line PE also connected to the electronic ballasts.

The already mentioned opto-couplers OK1 to OK3, which are connected to one another in series with an optical waveguide LWL as an optical signal line, which likewise produces a connection to a light-emitting diode D as an optical signal generator, are connected to the aforementioned digital drive connections DA.

The light-emitting diode D is supplied via a filter F of the phase line L1 and the neutral conductor N, wherein the phase line L1 must be switched by a button T1 as a dimmer switch and an optional second button T2 as parallel-connected second dimmer switch. If the first dimmer switch T1 or, in the optional case, one of the two dimmer switches T1 and T2 is pressed, the supply current is filtered through the filter F to generate a light signal in the light-emitting diode D. For this purpose, only a comparatively small current of the order of magnitude of a few mA is required, which is very favorable in relation to the currents required for electrical dimming signal lines, in particular for larger lighting installations. Accordingly, the filter F can be made small and also designed to be integrated with the probe or buttons D1 and D2.

The light signal generated by the light-emitting diode D is supplied via the optical fiber LWL the three optocouplers OK1 to OK3 and forwarded by them as an electronic digital signal to the respective control terminals DA of the ECGs. The ECGs therefore have a dimming signal generated by the button operation, which they can evaluate according to their duration and can be used for switching on and off from or in dimming stages as well as for the continuous or stepped changing of dimming levels. It can the optical fiber LWL between the optocouplers OK1 to OK3 and in particular between the optocouplers and the light-emitting diode D as an optical signal generator without special circumstances relatively long fail. In particular, there are no difficulties due to electromagnetic interference. Together with the filtering of the supply current of the diode, this ensures a particularly interference-free dimming signal, so that the ECGs can evaluate the duration of the dimming signal without interference by counting zero crossings. These include the zero crossings that occur at 50 Hz every 10 ms.

The maximum signal line length is significantly increased in comparison to electrical signal lines, with special suppression measures can be omitted, and here can be about several hundred meters in principle here.

Incidentally, the control inputs of the electronic ballasts are de-energized, although the one or more buttons T1 and T2 are powered by one phase.

The optocouplers OK1 to OK3 are implemented in the present case integrated in the ECGs. Also, between the optical fibers LWL and the optocouplers OK1 to OK3 known per se optical connector elements are used. This also applies to the connection between the light emitting diode D as a signal generator and the optical fiber LWL.

The exemplary embodiment shows how a plurality of ECGs can be controlled by a serial interconnection between the optocouplers OK1 to OK3. Of course, star-shaped interconnections are possible or the supply of several ECGs by an optocoupler.

The digital signal transmission between the optocoupler (s) and the ECGs may conform to the DALI standard, but may also be another digital transmission path, for example according to the standard used by the manufacturer OSRAM, which is known under the brand name "touch-dim". An advantage of the invention may also lie in the fact that the dimming signal inputs are basically free of voltage. In conventional solutions, on the other hand, if the signals corresponding to the mains voltage are also used for dimming, there is the danger that mains power will still be present at the dimming signal input even if the phase has failed. A worker or electrician may not be able to count on this, resulting in potential hazards.

Furthermore, the dimming signal inputs are basically galvanically isolated, because here only a light signal coupling takes place, so that there can be no mutual impairment of the circuits via these inputs even in short-circuit situations.

Figure 2 shows a variant of the embodiment of Figure 1. Here, a total of six electronic ballasts with the reference number ECG QT DALI 1-6 are provided and consequently also six lamps LA1-6. The ECGs are connected in pairs to common optocouplers OK1-3, the are connected via a respective optical waveguide LWL1-3 to a common light-emitting diode D for all optical couplers OK1-3 and optical waveguides LWL1-3. The three optical waveguides LWL1-3 can also be combined on a common optical waveguide, which is then uniquely connected to the LED D, ie the optical waveguide would be split.

Claims

claims

1. lighting system with a dimmable electronic ballast (electronic ballast QT DALI 1 - 6) and a dimming switch (T1 / T2) connected to the ballast (ballast QT DALI 1 - 6) for dimming control of the ballast,

characterized by an optical signal transmitter (D) connected to the dimmer switch (T1 / T2), an opto-coupler (OK, OK1-3) electrically connected to the ballast (ECG QT DALI 1-6), and an optical fiber (LWL, LWL1 - 3), which connects the optical signal transmitter (D) optically with the optocoupler (OK, OK1 - 3).

2. Lighting system according to claim 1, wherein the optocoupler (OK, OK1 - 3) structurally in the ballast (electronic ballast QT DALI 1 - 6) is integrated.

3. Illumination system according to claim 1 or 2, wherein the optical waveguide (LWL, LWL1 - 3) between the optical signal transmitter (D) and the optocoupler (OK, OK1 - 3) is continuous and preferably in one piece.

4. Lighting system according to one of the preceding claims, wherein the optical waveguide (LWL, LWL1 - 3) on the optocoupler (OK, OK1 - 3) and / or on the optical signal transmitter (D) can be mounted by an optical connector element.

5. Lighting system according to one of the preceding claims, wherein the ballast at least one optical input or for data communication via an optical waveguide (fiber optic ₁ fiber optic cable ₁

- 3).

6. Lighting system according to one of the preceding claims, wherein the optical signal transmitter (D) is preceded by a filter for filtering the current for generating the optical signal.

7. Lighting system according to one of the preceding claims with a plurality of ballasts (electronic ballast QT DALI 1-6) with a common optical signal transmitter (D), the at least one optical fiber (fiber optic, fiber optic 1-3) with the individual ballasts (electronic ballast QT DALI 1 - 6) is optically connected, and a common, via this signal generator (D) connected dimmer switch (T1 / T2).

8. Lighting system according to one of the preceding claims with a plurality of ballasts (electronic ballast QT DALI 1-6), which are electrically connected to a common optocoupler (OK1 - 3), wherein the common optocoupler (OK1 - 3) via a common optical waveguide (LWL1 - 3) and a common optical signal transmitter (D) with a common dimmer switch (T1 / T2) is connected.

9. A method for operating a lamp (LA1-6) with an illumination system according to any one of claims 1-8, wherein the method via a dimmer switch (T1 / T2), a dimming signal is input, via an optical signal transmitter (D) in an optical signal is converted over an optical waveguide (fiber optic ₁ LWL1

- 3) is transported to an optocoupler (OK ₁ OK1 - 3) and is converted by the optocoupler (OK ₁ OK1 - 3) into an electrical signal, which is an electronic ballast (ECG QT DALI 1 -

6) and for dimming control of this ballast (ballast QT DALI 1-6), the ballast (ballast QT DALI 1-6) operating the lamp (LA1-6) in response to the dimming control.