WO2009036795A1

WO2009036795A1 - Improved applicability of lamps with electronic ballast without a protective earth conductor

Info

Publication number: WO2009036795A1
Application number: PCT/EP2007/059563
Authority: WO
Inventors: Reinhard Lecheler; Siegfried Mayer
Original assignee: Osram Gesellschaft mit beschränkter Haftung
Priority date: 2007-09-12
Filing date: 2007-09-12
Publication date: 2009-03-26
Also published as: CN101803468B; CN101803468A; PL2189045T3; ATE536084T1; KR20100075495A; EP2189045B1; ES2375282T3; EP2189045A1

Abstract

The invention relates to improving the electromagnetic compatibility for lamps with integrated electronic ballast which are operated without a protective earth supply line, and involves capacitively coupling the electronic ballast housing to insulated conductive parts of the lamp by means of a capacitor (C3), possibly in conjunction with a further capacitor (C1) for fixing the touch voltage, and a radio frequency-absorbing damping element (F).

Description

Improved applicability of luminaires with electronic ballasts without PE

ladder

Technical area

The present invention relates to lights with integrated electronic ballast (ECG).

State of the art

The term "luminaire" means a lighting device designed for the installation of a lamp or already containing a built-in lamp, which has a housing, a frame or a reflector for the lamp beyond the lamp and a connection terminal for the power line. The term "lamp" in turn here means the light source, such as a discharge lamp or a halogen lamp or even an LED or an LED module.

In this case, the invention relates only to such lights that include an integrated electronic ballast with protective earth terminal. If such luminaires are operated without the supply of a protective earth (PE conductor), they may have reduced electromagnetic compatibility (EMC) or increased contact voltages, or the ECG may malfunction.

Presentation of the invention

The object of the invention is to provide a luminaire which, even when operated without a protective earth lead, offers improved usability in terms of EMC or touch voltages. The problem is solved by a luminaire with integrated electronic ballast ECG having a protective ground connection and a luminaire connection terminal AK without protective earth connection of the luminaire itself, characterized by a first capacitor C3 integrated in the luminaire connection terminal, which has at least one conductive insulated part of the luminaire MP connects to the protective earth terminal PE of the electronic ballast.

As a precaution, it is stated that the disclosure also relates to a method for operating such a luminaire and that the various features should also be regarded as disclosed for the method category, without any further explicit distinction being made between the device and method categories below.

Preferred embodiments are given in the dependent claims.

Namely, the inventors have recognized that parasitic capacitances of conductive parts of the luminaire which are insulated from operating voltages and currents, for example conductive housings, metallic reflectors or mounting plates of the luminaire housing, cause a coupling to operating currents leading lines within the luminaire. This coupling can reduce the EMC of the luminaire with regard to sturgeon resistance and storeroom transmission and also enable the generation of contact voltages of up to a few hundred volts. Both lead to problems with compliance with the relevant standards. In addition, the inventors have recognized that it is possible in the TOE by coupling voltage peaks into the circuit electronics, in particular of integrated circuits, may malfunction during operation.

The idea underlying the invention is to produce a conductive high-frequency alternating current connection between conductive insulated luminaire parts, in particular housing or mounting parts, and the protective earth connection of the ballast by means of a capacitor. High-frequency common-mode interference, which, for example, has its origin in the high-frequency generator of the electronic ballast, shorts this capacitor short. In this case, the galvanic separation of housing or assembly parts and live cables within the luminaire is not canceled and the optional use of a special type of capacitor does not affect double or reinforced insulation distances.

The potential difference of these parts and the protective earth is hereinafter referred to as Beruhr voltage, regardless of whether the parts are actually beruhrbar during operation. The touch voltage can be fixed by means of one or more additional capacitors between the light part and one or both power lines. For this purpose, the luminaire part in question may be additionally connected, for example by only one further capacitor, to the phase conductor (L-conductor) or the neutral conductor (N-conductor). In another variant of this idea, L and N conductors are connected by two further capacitors connected in series, wherein the luminaire part in question is additionally connected to the common point of the capacitors. The capacitors used preferably have a dielectric strength in the range of a few kilovolts and do not lose their insulating capability even in the case of a malfunction. These conditions are met, for example, by capacitors of the type 'Y ¹ known from the prior art. Their capacity should be small enough to ensure a sufficiently small amount of current during normal operation. The capacitance of the capacitors is in this case down through the values 1OpF, 10OpF and 50OpF, the larger, the more preferred, and upwardly limited by the values 5nF, 1OnF, 22nF, the smaller, the more preferred. Ideally, in many applications, the capacity is in the range of about 2nF.

The capacitor according to the invention or the capacitors according to the invention are used in luminaires which are designed for operation without a PE supply line. However, the terminal in which the capacitors are integrated can have not only two (for N and L conductors), but also three terminal contacts (for N, L and PE conductors). It is conceivable that the manufacturer envisages operation without PE supply (and the luminaire protection concept is designed accordingly), but for reasons of cost, in order to simplify production, or for looping through the PE conductor to other consumers Terminal block with three terminal contacts installed, whereby the PE contact inside the luminaire is then no longer interconnected. In this case, there were three terminal contacts, the PE contact does not form a protective contact of the lamp itself.

Furthermore, the inventors have recognized that in the circuit for fixing the contact voltage by the in duktivitaten the power lines resonantly excessive high-frequency alternating currents in a capacitive connection according to the invention between the lighting part and the one or more power lines can occur.

A further embodiment of the Beruhrspannungsflxierungs- circuit therefore provides, by high-frequency radiation absorption high-frequency currents in a line between the network conductors or the respective lighting part to be under pressure. For this purpose, a damping element causes high-frequency radiation losses through material-specific high-frequency vapor-damping properties in the relevant frequency range and thus reduces the amplitude of alternating currents of corresponding frequencies. In particular, materials with suitable magnetic properties, which can evaporate due to magnetic HF losses, come into question as a damping element. Ferromagnetic ceramics, which are known as Dampfungsfernte, in particular iron oxide, are particularly suitable for this purpose.

The damping element should preferably not be integrated into current-carrying conductors themselves, but should be attached only in their vicinity. Preferably, the damping element surrounds the conductor by being a body having a through opening. In particular, so-called pearls come into consideration, so small ball-like body with a hole, rings, or small tubes.

Experience also shows that relatively high inrush current peaks can occur when switching on lamps powered by electronic ballasts, especially if the ballasts are relatively high on the emitter side have large capacitors. Such capacitors are common in many ballast types, for example, as an intermediate circuit storage capacitor. The inrush current peaks lead to loads on the components affected by the current peaks and can also trigger fuses, in particular if several ballasts with such properties are operated together on a fuse. This means that the inrush current peaks that are meaningless for continuous technical operation can considerably reduce the number of ballasts that can be operated together on a fuse.

On the other hand, the production of ballasts and lamps is under considerable cost pressure, so that additional measures to limit the current, for example by power factor correction circuits with inherent current limiting function, are in many cases practically out of the question.

As a further embodiment, the circuit according to the invention is therefore combined with an inrush current limiting circuit. The inrush current limiting circuit is defined in the most general sense that when it is switched on in the switch-on phase, it first generates a voltage drop in the line in which the inrush current peak would otherwise occur, and then this voltage drop then becomes relatively fast, for instance in a time of at most 500 ms , disappears or decreases significantly.

In a concrete embodiment of the inrush current limiting the voltage drop can be generated via an open additional switch in the line, which is closed only delayed, in the area small instantaneous values of the applied supply voltage and preferably at the voltage zero crossing. If the supply of the ballast is then started with small or even near zero supply voltage values, the inrush current is limited and in particular capacitors in the ballast can be charged without problems due to the small supply voltage values.

In another embodiment, the voltage drop in the Emschaltstrombegrenzungsschaltung is generated by an initially high resistance in the line in which otherwise the inrush current peak would occur. Also, this resistance should then disappear in a relatively short time, such as the highest 500 ms, or decrease by a factor of at least 50. The initial resistance to inrush current limiting depends on the wiring and may be in the range of 50 Ω to 1 kΩ, for example.

A favorable possibility for realizing the switch-on current limitation consists for example in a thermistor or "NTC"("Negative Temperature Coefficient", ie resistance element with increasing temperature as the temperature increases). When switching on, the thermistor is initially still cold or room warm and thus relatively high impedance. The current can thus be limited to contractual values, but heats up the thermistor relatively quickly and thus converts it into a much lower-impedance state. In continuous operation, the low power loss in the thermistor suffices to maintain a sufficiently low resistance value therein. Depending on the ambient thermal conditions, this may depend on conditions, the type of thermistor and the load current to set a suitable temperature and resistance balance.

Another implementation of the inrush current limiting circuit is a relay with a resistor in parallel. The resistor initially, with the relay open, the initial current limit. The relay can either be closed via a separate timer circuit and then bypasses the resistor (or can be closed by the applied voltage and a time delay element) or can also be controlled directly by the applied voltage and then closes with a for Relay typical time delay. One can therefore depend on the technical data of the relay used, d. H. its design-related pull-in delay, add another timer or delay circuit or not.

An advantage over the variant described above is that the resistance value in continuous operation can be particularly low and the resistance value at the inrush current limit is freely adjustable. Furthermore, there are no thermal inertia as in the case of thermistors, so that even quick disconnection and reconnection processes are unproblematic.

An alternative to the described combination of relay and resistor consists in a timed switching transistor with a resistor connected in parallel. In contrast to the "classic" relay, the switching transistor is practically wear-free. The in principle more complex circuit structure does not necessarily have to result in a higher price.

Instead of the switching transistor, it is also possible to use a thyristor, TRIAC or IGBT, which is triggered and / or switched on time-controlled after switching on and thus becomes low-impedance.

The timing of the two variants described above can be realized via an RC element, but can also be carried out in an advantageous manner by a microcontroller already provided in many modern electronic ballasts or another electronic control of the ballast.

Finally, an inrush current limit can also be set by the controlled delayed activation of a transistor.

Ib tors done. This controlled turn on may mean a timed slow turn on. "Slow" here means that the transistor reaches its full conductivity during the switch-on process over a period of a few 10 ms. For this, the transistor, about one

20 MOSFET, driven according to time-controlled. The parallel resistor can therefore also be omitted if the switching transistor is sufficiently strong.

Preferably, however, an additional circuit between a control terminal of the transistor and a

Provided 25 more of its terminals, which controls in response to the current to be limited by the transistor, the control of the control terminal, so in particular limits the potential at the control terminal. Such a circuit then limits in the switch-on process,

30 in which otherwise current peaks would occur, the current through the transistor by not completely closing it. After completion of the actual turn-on operation, when inrush current peaks are no longer to be feared, the circuit may preferably turn on the transistor completely, but this is not absolutely necessary. For the rest, reference is made to the explanations of the exemplary embodiments.

Finally, it is advantageous if a thermal fuse is provided. This may be a simple fuse or other thermally tripping fuse. This can prevent the components according to the invention from causing a danger in the case of a short circuit in the ballast.

In all variants of the invention, it is generally preferred to integrate, in addition to the capacitor according to the invention / capacitors according to the invention optionally the Dampfungselement / the Dampfungselemente or optionally the Emschaltstrombegrenzungsschaltung in the terminal. The term "integrated in" here means that the components should be included or held in the terminal including its insulating support, so that they can be mounted together with and in the terminal by the lighting manufacturer or ballast manufacturer and possibly even already be purchased.

The integration of the inventive circuits in the

Terminal has the advantage that the applicability of the lighting device in a particularly simple manner and without interference with the actual circuit of the ballast equipment, can be improved. The terminal provided with the circuits can be manufactured as a separate part and used in a otherwise unchanged technical environment. In particular, there is no need for the manufacturer to provide additional protective circuits in the electronic ballast and line filter. These measures always mean a high overhead.

Thus, the advantages of an unchanged series production of the ballasts or lamps can be combined with a simple and pragmatic solution for improving the EMC or Berührungsspannungsflxierung the Beruhrspannung or for inrush current limit.

Particularly advantageous embodiments can be found in the dependent claims.

Short description of the drawing

Incidentally, the invention is explained in greater detail on the basis of exemplary embodiments, wherein the disclosed individual features are also essential for the invention in other combinations and the description has only an exemplary character, that is, does not restrict the subject matter of the invention.

Fig. 1 shows a schematic circuit diagram of a lamp with two Y-capacitors as a first Ausfuhrungs- example.

Fig. 2 shows a schematic circuit diagram of a luminaire with three Y-capacitors as a second Ausfuhrungs- example. Fig. 3 shows a schematic circuit diagram of a lamp with two Y-capacitors and a damping element as a third embodiment.

Fig. 4 shows a schematic circuit diagram of a lamp according to Fig. 3 with a thermistor for inrush current limiting as a fourth embodiment.

FIG. 5 shows a schematic circuit diagram of a luminaire according to FIG. 3 with a thyristor and parallel resistor for inrush current limiting as a fifth exemplary embodiment.

Fig. 6 shows a schematic circuit diagram of a lamp according to Fig. 3 with a switching transistor and a shunt resistor for inrush current limiting as the sixth embodiment.

Fig. 7 shows a schematic circuit diagram of a lamp according to Fig. 3 with a relay and shunt resistor for inrush current limiting as the seventh embodiment.

Fig. 8 shows a schematic circuit diagram of a lamp according to Fig. 3 with a linearly operated MOSFET for inrush current limiting eighth embodiment.

9 shows a schematic circuit diagram of a luminaire with a microcontroller as the drive source for a switching transistor for inrush current limiting as the ninth exemplary embodiment.

10 shows a schematic circuit diagram of a luminaire according to FIG. 3 with clocked MOSFET and a smoothing circuit for inrush current limiting as tenth exemplary embodiment.

11 shows a schematic circuit diagram of a luminaire according to FIG. 3 with a voltage-dependent switched MOSFET for inrush current limiting as eleventh exemplary embodiment.

FIG. 12 shows current and voltage waveforms in a luminaire without inrush current limiting circuit according to the invention.

Fig. 13 shows current and voltage waveforms in a luminaire with inventive inrush current limiting circuit

Preferred embodiment of the invention

In Figure 1, the interconnection of a erfmdungsgemaßen circuit is shown in a light in the context of a highly schematic block diagram. On the left is a network connection with phase conductor L and neutral conductor N, which is led to a luminaire connection terminal AK via a network supply line that is not closer to one another. The luminaire connection terminal AK is a uniform plastic housing - represented by the rectangle - with known built-in terminal contacts for the lines L and N, but without PE connection contacts. Capacitors Cl and C3 are Y capacitors with a capacitance of 2.2nF and 1.5nF, respectively. The protective earth terminal PE of the electronic ballast is connected via the capacitor C3 to an insulated conductive luminaire part MP, such as a housing ground terminal contact, a metal housing Reflector or a mounting plate or plate connected. Both capacitors are mounted in the luminaire connection terminal. The line between the capacitor C3 and the mounting plate MP may for example consist of a wire bridge. The capacitor Cl connects the mounting plate MP and the phase conductor L. The capacitor Cl can also be used between the mounting plate MP and the neutral conductor N. In the case illustrated in FIG. 1, the potential of the mounting plate MP is RF-technically fixed at the mains voltage potential. However, the capacitor C1 could also connect the protective earth terminal PE itself to the phase conductor L or the neutral conductor N. To measure the capacitance of the capacitor Cl, it should be noted that the capacitor C1 represents a high impedance on the one hand for possible contact currents arising, for example, from touching the mounting plate MP, and a low impedance on the other for HF currents. This ensures that mains currents supplied by the network can not exceed contractual or standard values and that HF stor- stroms are short-circuited. This condition is easy to fulfill because the grid potential on the time scale of the RF disturbances is quasi-static.

FIG. 2 shows a modification of the circuit arrangement in FIG. 1. Em further Y capacitance C2 integrated in the terminal, whose capacitance m preferably corresponds approximately to that of the capacitors C 1 or C 3 and which more preferably does not deviate more than 50% from that of the capacitor C 2 and which is ideally equal to that of the capacitor C2, connects the mounting plate MP to the neutral conductor N. If the capacitance of the capacitor C1 is equal to that of the capacitor C2, the pole is The potential of the mounting plate MP is fixed at half the mains voltage potential. But the capacitor C 1 and C 2 common point could also be contacted between the capacitor C3 and the protective earth terminal PE itself. The capacitors Cl and C2 not only cause a Beruhrspannungsflxierung, but they also allow the neutralization of symmetrical Storspannungen and act effectively as a line filter.

FIG. 3 shows, on the basis of FIG. 1, Y capacitors C 1 and C 3 integrated in the lamp terminal and a damping element, in this case a ferritic element F. The capacitors and their arrangement correspond to the situation illustrated in FIG. The ferrite bead F is seated on a terminal internal line piece which connects the mounting plate MP to the capacitor C1. In the same way, however, it could also be mounted inside the terminal between the capacitor C1 and the phase conductor L. As already mentioned in the text to FIG. 1, the capacitor Cl could just as well connect the neutral conductor N to the mounting plate MP instead of the phase conductor L or one of the power conductors to the protective earth connection PE.

The damping element F by high-frequency radiation absorption vaporizes resonant high-frequency alternating currents which arise from parasitic inductances of the network conductor in conjunction with the capacitive coupling of conductive luminaire parts to the mentioned light-internal current-carrying conductors. In a circuit arrangement according to FIG. 2, a ferrite bead according to the invention could be mounted on a terminal internal line between the common point of the capacitors C 1 and C 2 and the mounting plate MP on the one hand, or the protective earth terminal PE on the other hand. On the other hand, or there could be a Dampfungselement between the common point of the capacitors Cl and C2 and the capacitor Cl on the one hand and the capacitor C2 on the other hand, or between the capacitor C2 and the neutral conductor N and the capacitor Cl and the phase conductor L. In the latter Case, the circuit has so two damping elements.

FIGS. 4-11 show exemplary embodiments with inrush current limiting circuits. For the capacitors Cl and C3 and the damping element F in Figs. 4-11 reference is made in each case to the description of FIG.

In FIG. 4, a thermistor NTC is connected as inrush current limiting circuit in the phase line L. When switching on, the voltage applied to phase L is suddenly applied to the NTC NTC thermistor and, as a result of its residual conductivity, to the electronic ballast. At the ECG input there is a diode rectifier bridge, via which a DC link capacitor (not shown) is charged for the DC voltage supply of a converter of the ECG. The initially high-resistance thermistor NTC does not permit large charging currents, so that the charging process of the DC link capacitor in the electronic ballast is somewhat delayed. Meanwhile, the suitably dimensioned NTC thermistor is heated sufficiently to go into a low-coherence state. Thus, the charging process is completed and the Vorschaltgerat- and lamp operation is incidentally as usual.

The residual resistance of the thermistor NTC plays in this

Exemplary embodiment not essential. After switching off, wait a sufficient amount of time until the thermistor NTC has cooled down before the protective function is available again. However, this disadvantage is in many cases tolerable, at least if a fast startup and reclosure only affects one ballast or a small number of ballasts on a common fuse.

FIG. 5 shows a fifth exemplary embodiment and largely corresponds to FIG. 4, in which case the NTC thermistor is replaced by an inrush current limiting circuit shown in detail. This circuit has a built-up of four diodes D1-D4 rectifier bridge. Between the two nodes of the bridge, which do not coincide with the phase leads or leads, there is a resistor R and, in parallel thereto, a thyristor Thy polarized in the same sense as the diodes D1-D4. Instead, a TRIAC or IGBT could be chosen as well. The thyristor Thy is controlled by a symbolically represented by a timing diagram timing circuit, which can be realized by a simple RC element. In both polarity-different half phases of the phase L, the resistor is in the current path to the ECG shortly after switching on and before the ignition of the thyristor Thy. When the thyristor Thy is ignited, it short-circuits the resistor R as a result of its conducting state and thus terminates the inrush current limitation. S denotes a likewise integrated thermal fuse.

Both embodiments relate to a luminaire tenanschlussklemme AK. However, they can also be easily transferred to an ECG connection terminal. For this you have to use the terminal AK only as an integral part of the Introduce ECG. This ballast connection terminal could then be connected to a luminaire terminal via a separate cable or could itself already form the luminaire connection terminal.

Figure 6 shows a sixth exemplary embodiment, which is modified compared to the fifth exemplary embodiment of Figure 5 insofar as there is a switching transistor, namely a power MOSFET M, instead of the thyristor. The source, gate and drain contacts are labeled S, G and D, respectively. Incidentally, the explanations regarding FIG. 5 apply.

Figure 7 shows a seventh exemplary embodiment, which can be explained in the lightest compared to Figure 4. The thermistor NTC is here replaced by an ordinary ohmic resistance R, which incidentally, as in the second and third exemplary embodiment, typically 220 Ω. The resistor R can be bridged by a ReI designated classic relay, which see in the manner shown with its control contacts between the phase conductor L and the neutral conductor N and thus controlled with the switch-on. The marked with an X part of the relay should be symbolic of a pull delay, which is realized either due to design or by a delay circuit, such as an RC element.

Figure 8 shows schematically a circuit in which a controlled switching on of a MOSFET Tl is used for inrush current limiting. L and N again designate phase and neutral; S again denotes an integrated thermal fuse. The MOSFET Tl is with Help of four Gleichπchterdioden D5 - D8 so switched into the phase supply line L that it is always polaπtatsπch- tig flows through the supply current. Incidentally, the phase supply line L and the neutral conductor N are connected to a conventional rectifier bridge of four rectifier diodes (not separately shown in FIGS. 4 to 7) in the input of the electronic ballast. The DC link capacitor of the electronic ballast is denoted by CL and represents here the input capacitance of the electronic ballast responsible for the inrush current peaks. R1 (for example 10 kΩ) designates an ohmic resistance, which is only symbolic here for the load formed by the electronic ballast.

FIG. 8 also shows that the gate of the MOSFET T1 is connected to the neutral conductor via two resistors R4 (approximately 1 kΩ) and Rβ and a diode D9. The example here with 100 kΩ rated resistance Rβ is used for potential separation and forms together with a capacitor CR of z. B. 3.3 μF a smoothing member. A resistor R7, for example of 1 MΩ, is used to discharge the capacitor C2 in the off state.

The supply current of the phase conductor L through the MOSFET Tl is passed through a small resistor R3 of, for example, 1 Ω to produce a proportional voltage drop. This voltage drop is used for the monitoring of the gate voltage of the MOSFET T1, via a bipolar (npn) transistor T2, whose collector at the gate, its base at its source and its emitter via another resistor R5 (about 22 Ω) and the mentioned resistor R3 is at its base and thus at the source terminal of the MOSFET Tl. Finally, the gate voltage is limited via a zener diode ZD with a threshold voltage of about 18V.

After the phase is switched on at L, the capacitor CR is slowly charged via the resistor R6 and generates an increasing drive voltage for the gate of the MOSFET T1. As soon as a supply current begins to flow through the MOSFET T1 in its turn-on process, the resistance R3 drops a voltage which reduces the gate voltage of the MOSFET Tl when the emitter base threshold voltage of the bipolar transistor T2 is reached.

Thus, the increased internal resistance of the MOSFET T1 in the switch-on process can be used to limit the inrush current caused by the charging of the capacitor CL. As soon as the capacitor CL is charged to a substantial extent, the supply currents for the electronic ballast decrease so much that no voltage sufficient for closing the bipolar transistor T2 drops across the resistor R3. In continuous operation, therefore, the bipolar transistor T2 remains open and thereby the MOSFET Tl can be completely closed by the voltage applied to the capacitor CR in order not to generate unnecessary losses.

Incidentally, the emitter base threshold voltage of the bipolar transistor T2 with a large order of 0.7 V is so small that the resistor R3 can be sized correspondingly small and therefore low loss.

In alternative embodiments with a similar function, the bipolar transistor could also be produced by a zener diode with a correspondingly lower threshold voltage. which, when turned on as a result of a voltage drop across the resistor R3, limits the gate voltage at the MOSFET Tl. However, the threshold voltages necessary here were greater than the emitter base threshold voltage of the bipolar transistor T2 and would thus lead to a somewhat larger dimensioning of the resistor R3, that is, to somewhat greater losses.

Conversely, the circuit shown in Figure eight could also be made even more sophisticated by the bipolar transistor T2 serving here Pπnzipdarstellung is replaced by a Meßverstarkerschaltung with operational amplifiers. As a result, fluctuations due to temperature variation and specimen scattering could be avoided, and the threshold value of 0.7 V could be further reduced.

FIG. 9 shows a further exemplary embodiment in which a MOSFET M, as in FIG. 6, is actuated by a simple function of a microcontroller instead of the simple timer circuit shown there, which in many cases is already present in electronic ballasts and thus provides a connection to the unit with negligible additional expense Gate connection of the MOSFET M could get. For ballasts without current limiting function, this connection would then remain functionless, so that nothing stands in the way of the modular use of connecting terminals according to the invention. This applies in particular to the integration of the terminal into the ballast. Incidentally, the thyristor from FIG. 5 can also be activated in a corresponding manner via the microcontroller. FIG. 10 shows a further exemplary embodiment, in which a MOSFET, as in FIGS. 6 and 9, is controlled via a pulse-width-modulated PWM signal, that is to say it is clocked in time. Thus, an intermittent supply current is generated, which is converted by a serial smoothing circuit of an inductance L, a rectifier diode and a resistor R to a quasi-continuous current. The time constant resulting from L and R must therefore be adapted to the clock frequencies of the PWM signal. The diode corresponds to the polarity of the rectifier bridge Dl - D4. This exemplary embodiment shows that a controlled switch-on process in the exemplary embodiment from FIG. 8 can also be implemented in a control-technology digital manner, wherein the exemplary embodiment in FIG. 10 does not focus on the internal resistance of the MOSFET present in the switch-on process in the vicinity of the threshold voltage.

FIG. 11 shows a final exemplary embodiment which has similarities with the exemplary embodiments from FIG. 6 and FIG. In contrast to the exemplary embodiment from FIG. 6, the switching on of the MOSFET M is not delayed according to a predefined time scheme but in response to the detection of the voltage between phase L and neutral N. The voltage is switched at the next voltage zero crossing, so that the charging process of the Input capacitance of the ECG as a result of initially only m small values increasing voltage without power surge in problematic height. Therefore, the resistor R connected in parallel can be omitted and plays out in comparison to the exemplary embodiment Figure 8, the internal resistance of the MOSFET M in the power-up also not essential.

FIG. 12 and FIG. 13 show in comparison the effect of the inrush current limiting circuits according to the invention on the basis of measurements. The horizontal axis in both cases shows the time scale from 0 to 90 ms. The vertical axis, plotted on the left, shows a voltage scale in each case from -350 V to +350 V, and plotted on the right, a current scale from -100 A to +100 A in FIG. 9 and from -2 A to +2 A in FIG.

The time at the beginning of the graph corresponds to the actual switch-on time. In FIG. 12, this switch-on instant (approximately 5 ms) is selected such that a peak value of the phase L is reached, namely at just under 350 V. The voltage at the phase L oscillates sinusoidally. A saw tooth-like graph in the upper area, labeled U _z , shows the voltage at the already mentioned intermediate circuit capacitor m the ECG. This is practically at the peak of the supply voltage from the beginning and decays synchronously therewith as a result of the load within the TOE to be recharged with each new phase L peak. The correspondingly very rapid charging of the DC link capacitor at the switch-on time is manifested in a current pulse I which is practically infinitesimally short in FIG. 12 and immediately passes over a current curve which remains practically at 0 on the scale shown. The initial inrush current thus amounts to a large order of 100 A (it is shown reversed in the figure in FIGS. 12 and 13 so that it can be seen in addition to the voltage curve L). In contrast, Figure 13 shows a much slower charging of the DC link capacitor. In the variant according to the invention in FIG. 13 as well, the switch-on process takes place practically at the peak value of phase L (approximately at 5 ms). The slightly smaller triangle below the initial phase L triangle represents the first charging current pulse I. However, this is the case here In response to the change in vertical current scaling, the amplitude remains below 1.5 A. Synchronous with the sinusoidal oscillations of phase L, there are then two sinusoidal charging current pulses slightly decreasing in amplitude and time, with much smaller current amplitudes. At approximately 60 ms, the time signal corresponding to the fifth and the sixth exemplary embodiment from FIGS. 5 and 6 takes place (or if the thermistor NTC from FIG. 4 is sufficiently warm or the relay ReI from FIG. 7 is switched on). This is shown at the bottom in FIG. 13 by the rectangular rising curve. As a result, the charging current peaks become larger again in amplitude owing to the now inrush current limiting resistor R, but due to the increasing charging of the DC link capacitor, which is increasing independently of the switching process, is consistently shorter in time. They stabilize at an amplitude of well below 1 A, cf. The voltage waveform U _z therefore shows in the right half of the sawtooth waveform of Figure 12, in the left half of Figure 13 but a modulated with the same period and smeared otherwise over the already mentioned time of 60 ms increase , With the invention, the full DC link capacitor voltage is therefore delayed by a few 10 ms, however, the inrush current peaks can be reduced by almost a factor of 100 in this case.

Claims

claims

1. luminaire with integrated electronic ballast (ECG) having a protective earth connection and a luminaire connection terminal (AK) without protective earth connection of the luminaire itself,

characterized by a first capacitor (C3) integrated in the luminaire connection terminal, which connects at least one conductive insulated part of the luminaire (MP) to the protective earth connection (PE) of the electronic ballast.

2. Lamp according to claim 1 with a second capacitor (Cl), which connects one of the group of luminous part (MP) and protective earth terminal (PE) with one of the group of phase conductors (L) and neutral (N).

3. Luminaire according to claim 2 with a third capacitor (C2) between the network side facing away from the second capacitor (Cl) and that mains supply line which is not connected to the second capacitor (Cl).

4. Luminaire according to one of the preceding claims, wherein the capacitor / the capacitors (C1, C2, C3) have capacitance values between 1OpF and 22nF.

5. Luminaire according to claim 3 or 4, wherein the second and third capacitor (Cl, C2) have the same capacitance.

6. Luminaire according to one of the preceding claims, wherein the lamp terminal (AK) has no connection terminal contact for a PE conductor.

7. Lamp according to one of the preceding claims, wherein the conductive insulated part of the lamp (MP) a

Mounting plate is.

8. Luminaire according to one of claims 2 to 7 with a damping element (F), which consists of high-frequency radiation absorbing material and is adapted by high-frequency radiation absorption high-frequency currents in at least one of the group of second capacitor (Cl) and third capacitor (C2) Steaming the line containing the lamp.

9. Luminaire according to claim 8, wherein the Dampfungsele- element (F) has a high frequency absorbing ferrite.

10. Luminaire according to claim 8 or 9, wherein the damping element (F) is a closed passage through a body and through the Durchgangsoff- tion runs the line to be steamed in the high frequency currents.

11. Luminaire according to one of the preceding claims with an inrush current limiting circuit (NTC, Dl-D4, R, Thy, M, ReI, L, Tl, T2, R1-R7, ZD, CR), which is designed so that they When the lamp is switched on, excessive inrush current is prevented by a voltage drop in the inrush current limiting circuit (NTC, D1-D4, R, Thy, M, ReI, L, T1, T2, R1-R7, ZD, CR) during the switch-on phase.

12. Luminaire according to claim 11, wherein the inrush current limiting circuit has a voltage monitoring circuit and a controllable switch and is designed to close the controllable switch ter after switching on the lamp only in a voltage zero crossing.

13. Luminaire according to claim 11, wherein the inrush current limiting circuit (NTC, D1-D4, R, Thy, M, ReI, L, T1, T2, R1-R7, ZD, CR) is designed so that they at power the lamp initially provides a high resistance (R, Tl), which is then reduced.

14. Luminaire according to claim 13, wherein the inrush current limiting circuit (NTC) has a thermistor (NTC).

15. Luminaire according to claim 13, wherein the inrush current limiting circuit (R, ReI) comprises a relay (ReI) with a parallel resistor (R).

16. Luminaire according to claim 13, wherein the inrush current limiting circuit (D1-D4, R, M) comprises a timed switching transistor (M) with a parallel resistor (R).

17. Luminaire according to claim 13, wherein the inrush current limiting circuit (D1-D4, R, Thy) has a timed thyristor (Thy), TRIAC or IGBT with a parallel resistor (R).

18. Luminaire according to claim 16 or 17, wherein the time control via a in the electronic Switching device (ECG) integrated microcontroller takes place.

19. Luminaire according to claim 13, wherein the inrush current limiting circuit (L, D5-D9, Tl, T2, R1-R7) has a controlled turn-on transistor (Tl).

20. Luminaire according to claim 19, wherein between a control terminal of the transistor and a further terminal of the transistor, a circuit (T2, R3-R7, ZD, CR) is connected, in response to the m the transistor (Tl) guided current the Steueran - Final potential limited.

21. Light according to one of claims 11-20, which has a thermal fuse (S).

22. Luminaire according to one of the preceding claims, wherein the at least one element selected from the group consisting of the second capacitor, the third capacitor, the damping element (F) and the Emschaltstrombegrenzungs- circuit (NTC, D1-D4, R, Thy, M, ReI , L, Tl, T2, R1-R7, ZD, CR, S) is / are integrated in the luminaire connection terminal (AK).