EP0374724A1 - Electrical supply rail for lighting fixtures - Google Patents

Abstract

An electrical supply rail for lighting fixtures, in particular for low voltage tungsten-halogen lamps has at least two mutually insulated rail conductors (5, 6), the mains voltage being converted via a converter into the voltage assigned to the lamp to be switched on. According to the invention, the converter is constructed as a control device (1) which converts the mains voltage into a high frequency voltage on the rail conductors (5, 6), there being arranged on the electrical supply rail or on the lighting fixture, at the tapping point of each lighting fixture (13-16), a high frequency transformer (11) or a HF choke (12), which converts the higher voltage present on the rail conductors (5, 6) into another voltage matched to the particular lighting fixture (13, 16) to be switched on. <IMAGE>

Description

The invention relates to a busbar for lighting fixtures, in particular for low-voltage halogen incandescent lamps, fluorescent lamps, discharge lamps and the like, with at least two mutually insulated rail conductors, in which the mains voltage is converted via a converter to the voltage assigned to the lamp to be switched on.

A disadvantage of the previously known systems, especially in their use for low-voltage halogen incandescent lamps, was that the current-carrying parts had to be dimensioned large in order to be able to accommodate the high current flow densities.

The invention has for its object to further develop a busbar for the lighting fixtures mentioned above so that the current-carrying parts of the busbar can be dimensioned smaller.

To achieve the object, the invention is characterized in that the converter is designed as a control device which converts the mains voltage into a high-frequency voltage on the rail conductors, and that at the tap point of each lighting fixture on the busbar or on the lighting fixture, a high-frequency transformer or an HF Throttle is arranged, which converts the voltage applied to the rail conductors into another voltage that is adapted to the lighting fixture to be switched on in each case.

According to the invention, a control device is therefore available, which

AC mains voltage of z. B. 220 volts 50 Hertz in a corresponding high-frequency AC voltage of 220 volts effectively converted at a frequency of 20 to 200 kHz.

The essence of the invention is that now instead of the conventionally used low-voltage transformers, which are normally present at 220 volt busbars and z. B. are assigned to a lamp, instead, small-sized high-frequency transformers can be used, which are small. They are 30 times smaller than conventional low-voltage transformers.

The advantage of the invention is that a relatively harmless high-frequency voltage is transmitted via the current-carrying parts of the busbar, which results in a contact voltage which is harmless because dangerous frequency conduction through deeper tissues of the human body is avoided in the frequency ranges used.

Conventional transformers have edge lengths of 10 x 10 x 10 cm and an iron core, while the HF transformer according to the invention has only edge lengths of 2 x 2 x 2 cm for the same power and carries a ferrite core. This also makes the transformer lighter; it is therefore not necessary to provide large-sized fastenings for the busbars and the transformers according to the invention can even be integrated in the lamps, which leads to an attractive design.

In a further development of the invention, it is possible to integrate the transformer according to the invention into the adapter, ie into the coupling point at which the lighting fixture attaches to the busbar.

Another advantage is that due to the voltage used on the busbar, only a small power loss can be visualized. This reduction is achieved in two areas, firstly there is a reduction in the transport power loss along the conductor rail and secondly the power loss that occurs at the switch-on point of the lamp body on the conductor rail is reduced - so that heating and premature wear of the contacts and a risk of arcing the assembly or implementation of the luminaire body is avoided when the rail is live.

There is no fear of radio interference from the radio frequency on the conductor rail because the conductor rail is guided as a self-contained system and thus shields itself as a Farady cage.

Another important advantage of the invention is that fluorescent lamps can be connected to the busbar system according to the invention with little effort, because instead of the large-sized iron core-carrying chokes, a small-sized HF choke can now be used. Again, the dimensions of such a choke are reduced by a factor of 30 compared to conventional iron core chokes.

Another important advantage of the invention is that the control device, which is used to generate the high-frequency voltage, only has to be present once in the busbar, and its dimensions are so small that it can be integrated into the busbar itself. It is also possible to integrate this control device into an adapter piece in the busbar.

There is therefore no need to multiply such a control device itself at the coupling point of the respective lighting fixture use.

Of course, it is possible to operate the busbar system according to the invention not only with two conductors, but also with several conductors, the conductors going beyond two being used for the separate control of the individual lighting fixtures.

It is also possible to bring out additional tapping points on the control device in order to simplify the control circuit for a fluorescent lamp. When using high-pressure lamps, the previously mentioned tapping points on the control device also serve to produce a separate starter circuit.

The subject matter of the present invention results not only from the subject matter of the individual patent claims, but also from the combination of the individual patent claims with one another. All information and features disclosed in the documents - including the summary -, in particular the spatial design shown in the drawings, are claimed to be essential to the invention insofar as they are new to the prior art, individually or in combination.

The invention is explained in more detail below with the aid of drawings which illustrate only one embodiment. Further features and advantages of the invention which are essential to the invention emerge from the drawings and their description.

• Figur 1 ein Blockschaltbild eines Stromschienensystems nach der Erfindung mit mehreren verschiedenartig angeschlossenen Beleuchtungskörpern;
• Figur 2 schematisiert ein Ausführungsbeispiel für ein Ansteuergerät
• Figur 3 eine alternative Ausführung eines Leistungsteils.

Show it:

• Figure 1 is a block diagram of a busbar system according to the Invention with several differently connected lighting fixtures;
• Figure 2 schematically shows an embodiment for a control device
• Figure 3 shows an alternative embodiment of a power section.

In Fig. 1, the AC line voltage of 230 volts rms, 50 Hertz is introduced into the control device 1. It arrives in a rectifier network 2, where it is first rectified. Then it reaches an inverter 3, where it is converted to a higher frequency, preferably in the range from 20 to 200 kHz.

The lower range of 20 kHz should not be undercut, because otherwise the hearing range will be reached and the upper range of 200 kHz should not be exceeded, because otherwise the high-frequency power losses in the busbar system become too large.

A frequency in the range from 30 to 50 kHz is preferred here.

At the output of the control device, an alternating voltage of approximately 230 volts is then effectively present on the rail conductors 5, 6 at a frequency in the range from 20 to 200 kHz.

Various lighting fixtures 13, 14, 15, 16 are now connected to this busbar system with the rail conductors 5, 6.

The respective connection takes place via tapping points 7, 8, of which lines 9, 10 each lead into a high-frequency transformer 11. The HF transformer is small and has for example with a power of 100 VA, 40 kHz dimensions of 2 x 2 x 2 cm and a ferrite core. The respective lighting fixture 13 is connected to the output of the HF transformer and, in a preferred exemplary embodiment, is designed as a low-voltage halogen incandescent lamp.

It goes without saying that a large number of such lighting fixtures 13, 14 with associated HF transformers can be connected to the busbar system consisting of the rail conductors 5, 6.

The number of lighting fixtures that can be connected depends on the output power of the control device 1.

In addition to the use of low-voltage halogen incandescent lamps, corresponding other types of lighting fixtures can also be connected, such as. B. fluorescent lamps 15 or high pressure lamps 16th

The fluorescent lamp 15 is connected via an RF choke, the choke in turn the small dimensions of z. B. 1.5 x 2 x 2 cm with a power of 58 watts. The fluorescent lamp 15 is associated with a starter 15a known per se.

Instead of such fluorescent lamps with high outputs, compact lamps with an output of 5 watts to 36 watts can also be connected, the RF chokes used being dimensioned correspondingly smaller for this purpose.

In a further embodiment, a high-pressure lamp 16 is connected via a further HF choke 18 and an ignition circuit 17. The output of such high-pressure lamps can be in the range between 35 and 250 watts and the type of high-pressure lamps can be different, e.g. B. high pressure sodium lamps, high pressure mercury lamps or metal halide lamps.

FIG. 2 shows a detailed circuit diagram of a control device 1 according to FIG. 1 as an exemplary embodiment.

The AC mains voltage 4 is fed via a radio interference suppression circuit 19 to a bridge rectifier 20, which outputs its pulsating DC voltage via a charging capacitor 21 to a corresponding power unit 23.

The power section is in the present embodiment, for. B. executed with mutually connected transistors which are controlled by a common control electronics 22.

Instead of using such transistors, other switching elements are of course also possible, such as. B. thyristors, field effect transistors or the like ..

At the output of the power section 23, an artificial HF zero point is formed via, for example, two capacitors 24 connected in series. At this artificial zero point, one rail conductor 5 attaches, while the other rail conductor 6 attaches to the output of the power section 23.

In the exemplary embodiment according to FIG. 3, the artificial center of conduction is achieved by a double bridge equipped with transistors.

It is therefore a simple frequency converter which generates a high-frequency AC voltage from the mains AC voltage and a large number of circuits are suitable for such frequency converters Expert familiar.

In the exemplary embodiment according to FIGS. 2 and 3, only two possible preferred circuit examples are given.

In the exemplary embodiment according to FIG. 3, two power sections 23, 23 'are connected in inverse relation to one another, the transistors shown here being designed as a bridge circuit, with transistors in the bridge diagonal always being connected through while the transistors of the other bridge diagonal are blocked and vice versa.

In addition to the two rail conductors 5, 6 shown here, a further conductor or a plurality of further conductors is provided in another embodiment, not shown in the drawing, one or more further conductors being provided for dimming the corresponding lighting fixtures, the control information being provided via these further conductors the assigned dimming circuits are transmitted.

Claims (8)

1. conductor rail for lighting fixtures, in particular for low-voltage halogen incandescent lamps, fluorescent lamps, discharge lamps and the like, with at least two mutually insulated rail conductors, in which the mains voltage is converted via a converter to the voltage assigned to the lamp to be switched on,
characterized in that the converter is designed as a control device (1) which converts the mains voltage into a high-frequency voltage on the rail conductors (5, 6), and in that at the tap point (7, 8) of each lighting fixture (13-16) on the busbar or a high-frequency transformer (11) or an HF choke (12, 18) is arranged on the lighting fixture and converts the voltage applied to the rail conductors (5, 6) into another voltage that is adapted to the lighting fixture (13-16) to be switched on changes. 2. Busbar according to claim 1, characterized in that the control device on the rail conductors (5, 6) generates an alternating voltage corresponding to the level of the voltage in the network in the frequency range from 20 to 200 kHz. 3. Busbar according to claim 1, characterized in that the preferred frequency range is 30-50 kHz. 4. Busbar according to claims 1 to 3, characterized in that the associated with a low-voltage halogen lamp with a power of 100 VA HF transformer (11) housing dimensions of about 2 x 2 x 2 cm. 5. Busbar according to claims 1 to 3, characterized in that the control device consists of a spark suppressor arranged on the network side (19), which is followed by a bridge rectifier (20) that the pulsating DC voltage generated by the bridge rectifier (20) a power part (23, 23 ') is supplied, the switching elements of which are switched through by control electronics (22) in the HF cycle. 6. A conductor rail according to claims 2 to 4, characterized in that an arrangement of capacitors (24) for generating an artificial zero point for one rail conductor (5) is arranged at the output of the power section (23, 23 '). 7. Busbar according to claim 2, 3 and 5, characterized in that the second line is driven by an inverter circuit operating in push-pull mode. 8. Busbar according to one of claims 1 to 3, characterized in that the HF choke assigned to a fluorescent lamp has housing dimensions of approximately 1.5 x 2 x 2 cm.

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