AU2006348910A1

AU2006348910A1 - EMC improvement by means of RF absorption in luminaires and electronic ballasts

Info

Publication number: AU2006348910A1
Application number: AU2006348910A
Authority: AU
Inventors: Reinhard Lecheler; Siegfried Mayer
Original assignee: Osram GmbH
Current assignee: Osram GmbH
Priority date: 2006-09-25
Filing date: 2006-09-25
Publication date: 2008-04-03
Also published as: CN101513130B; EP2067386B1; KR20090077929A; WO2008037292A1; ATE489837T1; DE502006008412D1; EP2067386A1; ES2356260T3; CN101513130A

Abstract

The invention relates to the improvement of the EMC of an electronic ballast or a luminaire with an integrated electronic ballast by means of introducing a radiofrequency-absorbing damping element (F), in particular a ferrite bead.

Description

PCT/EP2006/066715 - 1 2006P10335WOAU Description EMC improvement by RF absorption in luminaires and ECG Technical field This invention relates to a luminaire with integrated electronic control gear (ECG) and to ECG as such, in which the electromagnetic compatibility (EMC) is improved. Prior art In luminaires with electronic control gear and also in electronic control gear as such, interference may arise in the radiofrequency range, in particular between 20 and 30 MHz. This interference is caused by resonance phenomena between grounded metal parts of the luminaire or of the control gear and the surrounding environment close to the gear, with the inductance of the ground conductor feed line (PE) and the capacitive coupling between the metal parts of the luminaire housing, the control gear housing and the surrounding environment playing a particular role. These faults impair the EMC quality and can result in difficulties in terms of adherence to EMC requirements. Circuitry measures in ECG for reducing such interference which involve a certain amount of complexity are known. Description of the invention The invention is based on the technical problem of specifying a luminaire with integrated ECG and ECG itself which demonstrate improved electromagnetic compatibility in relation to such resonance phenomena in the radiofrequency range.

PCT/EP2006/066715 - la 2006P10335WOAU This problem is solved by a luminaire with integrated electronic control gear, characterized by a damping element which is made from PCT/EP2006/066715 - 2 2006P10335WOAU a material absorbing radiofrequency radiation and is designed to damp radiofrequency currents in a line of the luminaire between a PE connection terminal of the luminaire and a ground terminal in the luminaire, by means of radiofrequency radiation absorption, and electronic control gear for a lamp, characterized by a corresponding damping element, which is designed to damp radiofrequency currents in a line of the control gear between a PE connection terminal of the control gear and a ground terminal in the control gear. Preferred configurations are specified in the dependent claims. The term "luminaire" in this case incidentally relates, in contrast to the term "lamp", not to a luminous means as such, i.e. the use article appropriate for the actual generation of light, but to a lighting apparatus with, or for accommodating, a luminous means, i.e. a lamp. A luminaire therefore has a housing and often a shield, a reflector, translucent covering sheets of glass or the like. The basic concept of the invention consists in providing a damping element in the luminaire or in the control gear, which damping element produces radiofrequency radiation losses in the frequency range of interest as a result of material-specific, radiofrequency-damping properties, and therefore damps disruptive resonance phenomena and reduces the amplitude thereof. Particularly suitable here are materials with appropriate magnetic properties which can damp by means of magnetic RF losses. This applies in particular to ferromagnetic ceramic materials, in particular also materials of iron oxide, which are also known as damping ferrites PCT/EP2006/066715 - 2a 2006P10335WOAU Such a damping element should in this case preferably not be integrated in the conductor itself - the ferrites would in this regard also lack conductivity - PCT/EP2006/066715 - 3 2006P10335WOAU but should merely be fitted in the vicinity of the conductor. Preferably, the damping element surrounds the conductor by virtue of it being a body with a through-opening. So-called beads, i.e. small spherical bodies with a bore, rings or small tubes are particularly suitable. In the case of the control gear claimed per se, the line to be damped is present between the PE connection terminal of the control gear and the ground contact on the control gear housing or a corresponding part thereof. The line currents involved in the resonance phenomena therefore need to pass through this line. In the case of the luminaire, the PE connection terminal of the luminaire overall often differs from the PE connection terminal of the control gear integrated in the luminaire, or the control gear possibly also does not have a dedicated PE connection terminal. Preferably, the line to be damped by the damping element is in this case positioned between the PE connection terminal of the luminaire and the ground contact of a luminaire housing part which is also responsible for the resonance phenomena or of the luminaire housing as a whole. Capacitances which are linked to the luminaire housing (part) and contribute to the resonance phenomena then cause damped currents through this line. Secondly, a conductive housing of the integrated control gear can also be involved in considerable capacitances, with the result that it is likewise preferred for the line to be positioned between the PE connection terminal of the luminaire and the ground contact of the control gear housing. Preferably, both cases are true. In particular, the control gear ground contact can take place with respect to the luminaire housing (part), with the result that the currents to the control gear housing are also detected already by damping of the line PCT/EP2006/066715 - 3a 2006P10335WOAU between the PE connection terminal of the luminaire and the ground contact on the luminaire housing (part).

PCT/EP2006/066715 - 4 2006P10335WOAU In all variants of the invention, it is in principle preferred to integrate the damping element in the connection terminal. Where it has until now been mentioned that the damping element is intended to damp a line between the PE connection terminal and a specific ground contact, the expression "between" means the region from the actual connection contact for the external line onward. The preferred integration in the terminal is intended to mean that the damping element is intended to be integrated in the connection terminal body, i.e. for example in a conventional luster terminal in the vicinity of the conductive piece between the connection contact for the external line and the internal connection contact, to be precise in particular in a form surrounding this conductive piece. The term "integrated in" therefore in this case means that the damping element is intended to be contained or held in the component part including its insulating holder, with the result that it can be fitted together with and in the terminal by the luminaire manufacturer or control gear manufacturer and possibly even purchased in this form. Brief description of the drawing(s) Figures 1-3 show three circuit arrangements according to the invention with a luminaire connection terminal with an integrated damping element. Figure 4 shows an interference spectrum of a luminaire with electronic control gear without damping of the radiofrequency interference. Figure 5 shows an interference spectrum of a luminaire with electronic control gear and with a luminaire connection terminal according to the invention with an integrated damping element in the circuit shown in figure 1.

PCT/EP2006/066715 - 4a 2006P10335WOAU Preferred embodiment of the invention Figure 1 shows a circuit arrangement according to the invention with a luminaire connection terminal LK with an integrated damping element F for a PCT/EP2006/066715 - 5 2006P10335WOAU luminaire with electronic control gear ECG. The damping element F is a radiofrequency-absorbing ferrite bead and is integrated in the luminaire connection terminal itself. In this case, said ferrite bead is positioned on the conductive connection between the terminal connection contact for the external PE mains feed line, on the one hand, and an internal line, which leads to the luminaire housing. The line section with the damping element F is therefore connected between the luminaire housing and the ground conductor PE, with in this case the electronic control gear ECG being connected to the ground conductor PE via the luminaire housing (or else a line) and finally the damping element. In this circuit arrangement, the damping element F absorbs the interference spectrum which results from the resonant oscillations of the luminaire housing and the housing of the electronic control gear, in particular from the capacitive couplings between the luminaire housing and the surrounding environment, and in this way damps the radiofrequency interference. Figure 2 shows a modification of the circuit arrangement shown in figure 1. In this case, a ferrite bead is likewise integrated in the luminaire connection terminal, but only positioned on a PE connecting line, with which the control gear ECG is connected to the external PE line via the luminaire connection terminal. The housing of the luminaire, as illustrated, is either connected to the external PE feed line independently thereof or could in this exemplary embodiment also be configured entirely without a ground contact, for example in the case of a plastic luminaire. In this case, therefore, the capacitive influence of the luminaire housing does not play a decisive role and is not taken into consideration in the damping in accordance with the invention. Conversely, in the variant in figure 3, only a conductive link to the line to the ground contact of the luminaire housing is affected by the ferrite bead F, which is likewise integrated in PCT/EP2006/066715 - 5a 2006P10335WOAU the luminaire connection terminal. Since the control gear ECG, in contrast to the variant in figure 1, is in this case connected to the external PE line via a feed line to the luminaire connection terminal, and this feed line is not also covered by the ferrite bead, PCT/EP2006/066715 - 6 2006P10335WOAU the capacitive influence of the ECG housing is not also taken into consideration here. In specific cases it may be uncritical. As a deviation from the figure, it could also be possible for a conductive and grounded ECG housing to be dispensed with owing to the grounding of the luminaire housing. However, it is naturally also possible for a second or a common ferrite bead to be provided for both housing ground feed lines. Figure 4 shows an interference spectrum (in dBpLV at 50 Q) of a luminaire with electronic control gear without a damping element and thus without radiofrequency interference suppression. Furthermore, in figure 4 the rated value curves to be adhered to for the quasi peak (QP) and average values (AV) are illustrated. The interference levels determined markedly exceed the rated values to be adhered to with respect to the quasi peak (60 dBpV) and average values (50 dBpV) in the frequency range of from 10 to 30 MHz, with the overshoot values being approximately 5 dBiV. Figure 5 shows an interference spectrum of the same luminaire with electronic control gear with a luminaire connection terminal and an integrated damping element with a circuit arrangement as shown in figure 1. The rated values prescribed in the frequency range of between 10 and 30 MHz with respect to quasi peak (QP) and average values (AV) are undershot, with the undershoot values being approximately 5 dBptV.

Claims

1. A lighting device, namely a luminaire with integrated electronic control gear (ECG) characterized by a damping element (F) which is made from a material absorbing radiofrequency radiation and is designed to damp radiofrequency currents in a line of the luminaire between a PE connection terminal of the luminaire and a ground terminal in the luminaire, by means of radiofrequency radiation absorption.

2. The lighting device as claimed in claim 1, in which the ground connection in the luminaire is a ground contact of at least part of the luminaire housing.

3. The lighting device as claimed in claim 1 or 2, in which the ground connection in the luminaire is a ground contact of at least part of the control gear housing.

4. The lighting device as claimed in one of the preceding claims, in which a ground contact of the control gear (ECG) is connected to the luminaire housing.

5. A lighting device, namely electronic control gear (ECG) for a lamp, characterized by a damping element (F) which is made from a material absorbing radiofrequency radiation and is designed to damp radiofrequency currents in a line of the control gear (ECG) between a PE connection terminal of the control gear (ECG) and a ground terminal in the control gear (ECG), by means of radiofrequency radiation absorption. PCT/EP2006/066715 - 8 2006P10335WOAU

6. The lighting device as claimed in one of the preceding claims, in which the damping element (F) has a radiofrequency absorbing ferrite.

7. The lighting device as claimed in one of the preceding claims, in which the damping element (F) is a body which is closed around a through-opening, and the line in which radiofrequency currencies are to be damped passes through the through-opening.

8. The lighting device as claimed in one of the preceding claims, in which the damping element (F) is integrated in a connection terminal (LK).