DE102014104365B4 - lighting device - Google Patents

Abstract

The invention relates to a lighting device (15) having a luminous means arrangement (16) which has two illuminant strands (17) each with a plurality of luminous means groups (18) connected in series. Each lamp group (18) is associated with a control circuit (21) of a control arrangement (20). For each light source strand (17) a control arrangement (20) is present. Via the control arrangement (20), the number of current-carrying lamp groups (18) can be increased or reduced in accordance with the course of a supply voltage (V1, V2) applied to the relevant light-source string. As a result, a current (IS1, IS2), which is recorded in total by a light-emitting strip (17), can be increased and reduced depending on the number of current-carrying light-emitting element groups (18). A voltage supply device (27) serves to provide the at least one supply voltage (V1, V2). A rectifier circuit 31 generates from the positive half-waves of all phase-shifted alternating voltages (U1, U2, U3) a pulsating first supply voltage (V1) to a first supply line (38) and from the negative half-waves a pulsating second supply voltage (V2) to a second supply line (39 ). To the supply lines (38, 39) in each case a light source strand (17) is connected.

Description

The invention relates to a lighting device with a lighting arrangement. The light-emitting device has at least one light-emitting strand. In this light source strand are several groups of lamps that are connected to each other in series. Each group of lamps has at least one lamp. In particular, semiconductor lamps, such as light-emitting diodes or light-emitting diodes are used as lamps. The lighting device also includes a power supply device. This provides a supply voltage to each one supply line. To each of the at least one supply line, a light source string is connected. Each illuminant strand is assigned a control arrangement in order to adjust the luminous power, for example, by controlling or regulating the current through the illuminant strand.

A lighting device with LEDs is for example off US 2013/0187551 A1 known. The voltage supply device has there an AC voltage source, which is rectified to generate the supply voltage. The rectified supply voltage is applied to the light source strand of several groups of lamps each having a plurality of LEDs. Each lamp group is connected in parallel to a control circuit of the control arrangement. As a result, each of the lamp groups can be short-circuited via the control circuit as a function of a control signal. The control arrangement can therefore increase the number of non-short-circuited lamp groups with increasing amount of the alternating voltage or the rectified supply voltage in order to adapt the current profile for power factor adjustment to the voltage curve.

Also known by Supertex Inc. is a CL8800 LED driver that can be used to drive a light source string with multiple sequential lighting groups that can be switched on and off.

A disadvantage of the above-described lighting device is the emergence of a flicker at twice the mains frequency, that is, for example, 100 Hz. In the zero crossing of the mains voltage or the rectified supply voltage extinguish all bulbs of the lamp assembly. According to the data sheet for the LED driver CL8800 from Supertex Inc., this can be alleviated by using a capacitor circuit whose capacitor charges during the current flow through the illuminant strand and discharges the supply voltage in the region of the zero crossing. However, the flicker can be reduced only slightly.

Although the flicker could be tolerated, especially if the lighting arrangement is used to illuminate areas in which people are not permanently (corridors, stairwells or the like). However, such flicker is undesirable especially in the field of workplaces. If, for example, monitors or rotating machine parts are present in the illuminated area, beating effects can occur which are not only distracting, but are also of physiological concern. Therefore, the use of the known lighting device in such areas is at least problematic.

DE 10 2007 040 152 A1 describes a lamp arrangement with a light source strand of a plurality of series-connected lighting means. A voltage supply device with an AC voltage source provides an AC voltage. A connected to the AC voltage source rectifier circuit generates from positive half-waves and the negative half-waves of the AC voltage, a pulsating supply voltage to a supply line to which the light source strand is connected. The light source strand is assigned a control arrangement with a plurality of control circuits, which are connected in parallel to a light source via a respective branch line. The control arrangement is configured to influence the branch flow through one or more of the branch lines.

It can therefore be regarded as an object of the invention to enable a more versatile usability of the lighting device and yet to achieve a good power factor adaptation by simple means. In particular, switching controller topologies with a power factor matching stage and an output stage are to be avoided, since these generally require a storage choke, EMC filters and other semiconductors for control and clocking.

This object is achieved by a lighting device having the features of claim 1.

The lighting device has two light-emitting strands. In each light source strand is a series connection of light source groups, each light source group may have one or more light sources. In particular, each group of lamps contains a series and / or parallel connection of a plurality of lamps, in particular semiconductor lamps.

The voltage supply device of the lighting device has two alternating voltage sources. The two alternating voltage sources each supply an alternating voltage, which are phase-shifted relative to each other. In a preferred embodiment, three alternating voltage sources are used, which preferably each have an outer conductor and the neutral conductor of the 3-phase alternating voltage network.

A rectifier circuit, which preferably consists of a plurality of diodes, is connected to the alternating voltage sources and provides a pulsating supply voltage at the at least one supply line. Each existing light source is assigned a supply line. The pulsating supply voltage to a supply line can be generated by the positive half-waves and / or the negative half-waves of the AC voltages of the available AC voltage sources by the rectifier circuit.

Each illuminant strand is also associated with a control arrangement, wherein a plurality of control circuits are present. Each control circuit is connected via a respective branch line with a respective associated light source group in series or in parallel thereto. Via the control circuit, the luminous flux can be influenced by the respectively associated light-emitting group and / or the branch current through the branch line.

By means of the control arrangement, it is therefore possible to vary the number of current flows used for the illumination, active lighting means groups. In this way, the current flow through the light source strand can be changed stepwise by increasing or decreasing the number of current-carrying light-emitting groups, so that an increasing or constant or decreasing current profile can be achieved by the light source arrangement for adaptation to the associated pulsating supply voltage. This makes it possible to achieve a good power factor adaptation with simple means.

In addition, at least two alternating voltages phase-shifted relative to one another are used to generate a pulsating supply voltage. This avoids flickering at twice the mains frequency or twice the frequency of the alternating voltages used. The phase-shifted alternating voltages can preferably be formed by the phases of the 3-phase alternating voltage network.

Alternatively or additionally, at least one of the alternating voltages can also be generated via a phase shifter circuit from one of the other alternating voltages. In this embodiment, however, there may be a deterioration of the power factor adjustment.

The alternating voltages are preferably sinusoidal alternating voltages which have the same frequency and / or the same amplitude.

There are two supply lines. The rectifier circuit generates a pulsating first supply voltage for the first supply line from positive half-waves of the available alternating voltages. The rectifier circuit generates a second supply voltage for the second supply line from the negative half-waves of the available alternating voltages. On each supply line, a light source string is connected in each case. Two light-emitting strands are thus operated independently of each other, whose pulsating supply voltages have a mutually phase-shifted course. In addition, two, three or more mutually phase-shifted AC voltages are used to generate each supply voltage. Overall, this results in a very balanced lighting of a range and disturbing beats in the operation of monitors or moving machine parts are avoided. In this arrangement, the component cost is low and the quality of the lighting is good.

In one embodiment, the rectifier circuit may include a first diode and a second diode for each AC voltage source present. Only one of the two terminals of each alternating voltage source is connected in each case via one of the first diodes to a first supply line and also in each case via one of the second diodes to a second supply line. The respective other terminal of each AC voltage source is connected to a reference line. As a result, a half-wave rectification is achieved.

In a non-inventive embodiment, the rectifier circuit can have two first diodes and two second diodes per existing alternating voltage source. Both terminals of each alternating voltage source are preferably connected in each case via one of the first diodes to a first supply line and also in each case via one of the second diodes to a reference line. As a result, full bridge rectification is achieved.

In a preferred embodiment, each control circuit is connected in series with the associated lamp group via the respective branch line connected to the control circuit, and therefore connected to the output of associated lamp group connected. By the control circuit, a branch flow through the branch line can be turned on and / or off and / or limited and / or controlled or regulated. Accordingly, the current is influenced by the following lighting groups. In this way, the number of current-carrying lamp groups can be changed very easily, so that the current through the light source for power factor adjustment adapted to the course of the supply voltage, ie increased, maintained or reduced.

Alternatively, it is also possible to switch the control circuits via the branch line in each case parallel to an associated light source group. Via the control circuit and the branch line, each light source group of a light source strand can be short-circuited if no current should flow through the associated light source group. Otherwise, the electrical line in the branch line is interrupted by the control circuit. This also makes it possible to adapt the current consumption of a light-emitting string to the applied supply voltage for power factor adaptation as described above.

At least several of the control circuits each have a controllable control switch in a preferred embodiment. The control switch is arranged in the branch line and can be switched between a conducting and a blocking state. In this way, the branch stream can be interrupted by the branch line or a flow of current can be made possible.

It is also possible to control, regulate or limit the size of the branch current when the control switch is conductive. For this purpose, the control circuit, for example, have a current sink, which is connected in series with the control switch, if it is present.

The switching state of the controllable control switch in a branch line may depend on an electrical variable in and / or on another branch line, in particular on an immediately adjacent branch line. About the control circuit, the electrical variable detected at another branch line and depending on the switching state of the controllable control switch can be changed. If the branch lines, which are connected to a light source, consecutively numbered 1, 2,..., I,..., N-1, n in the flow direction of the string current, the electrical quantity for the control switch of the branch line with the number i for i = 1, 2, ..., n - 1 in and / or on the branch line with the number i + 1 detected. The last branch line with the number n preferably has no control switch.

Alternatively, the control signal for the control switch can also be obtained by detecting an electrical quantity at another location, for example by detecting the supply voltage and / or the string current. The control switches in the branch lines could be switched via a control unit depending on the supply voltage and / or the string current.

Preferably, a capacitor circuit is present. The capacitor circuit has at least one capacitor and at least one controllable switch. The capacitor circuit is connected to an associated supply line. If several supply lines are present, several capacitor circuits can also be provided.

The capacitor circuit is preferably configured to charge the capacitor when the pulsating supply voltage of the associated supply line exceeds a predetermined amount. If a sufficiently high supply voltage is available, a sufficiently large current flows through all groups of lamps as a rule and the maximum luminous power is available. In this condition, part of the electrical power provided may be used to charge the capacitor. If the available electrical power decreases when the supply voltage drops in magnitude, the luminous power of the associated light source string also decreases. In order to reduce the difference between the maximum luminous power and the minimum luminous power, the capacitor can be discharged via at least one luminous means of a lighting group when the pulsating supply voltage falls below a predetermined further amount. A flickering of the lighting device can thereby be at least somewhat reduced.

The number of lamp groups per lamp string can be chosen arbitrarily, wherein in preferred embodiments of the lighting device at least 3 and a maximum of 5, 6 or 7 light-emitting groups are present.

Advantageous embodiments of the invention will become apparent from the dependent claims, the description and the drawings. Reference to the drawings preferred embodiments of the invention will be explained in detail below. Show it:

1 to 3 each a block diagram of an embodiment of a lighting device with two supply lines,

4 a non-inventive block diagram of a lighting device with only one supply line,

5 FIG. 2 a block diagram of a partial representation of a light-emitting-material strand with a plurality of light-emitting means groups, and of an exemplary embodiment of an associated control arrangement, FIG.

6 2 is a block diagram of a partial representation of a light-emitting-material strand with a plurality of light-emitting means groups and of a further exemplary embodiment of an associated control arrangement,

7 a schematic time course of three alternating voltages of three alternating voltage sources and the pulsating supply voltages generated therefrom, and also schematically the principle of a stepwise adjustment of a current intensity of a current through a light source strand to a supply voltage,

8th a schematic representation of the time-dependent course of two mutually phase-shifted pulsating supply voltages and the respective associated current through the light source strand and

9 a schematic representation of the time course of the supply voltage to a supply line and the current in the connected light-emitting strand in the non-inventive lighting device according to 4 ,

In the 1 to 3 is in each case an inventive embodiment of a lighting device 15 illustrated. The lighting device 15 has a lighting arrangement 16 on, the at least one light source strand 17 contains. Every light source string 17 consists of a series connection of at least two groups of lamps 18 , Each group of bulbs 18 contains at least one light source 19 , in particular a semiconductor illuminant, such as a light emitting diode. The bulbs 19 a lighting group 18 can each other in a series and / or parallel circuit to form the light source group 18 be arranged.

Each light source string 17 is a control arrangement 20 assigned. Every control arrangement 20 indicates according to the number of lamp groups 18 the associated light source strand 17 a number of control circuits 21 on. The control circuits 21 are in branch lines 22 arranged. With the help of the branch lines 22 is every control circuit 21 in series or parallel to the assigned lighting group 18 connected.

The lighting device 15 also has a power supply 27 on. The power supply device 27 provides for the supply of the lamp assembly 17 at least one AC voltage ready. In the preferred embodiments described herein, the power supply has 27 a first AC voltage source 28 for providing a first alternating voltage U1, a second alternating voltage source 29 for providing a second alternating voltage U2 and a third alternating voltage source 30 for providing a third AC voltage U3.

In the embodiments described here, each AC voltage source 28 . 29 . 30 formed by a phase of the 3-phase alternating voltage network. In other words, the first AC voltage source 28 by a first outer conductor L1 and a neutral conductor N of the 3-phase AC voltage network, the second AC voltage source 29 by a second outer conductor L2 and the neutral conductor N and the third AC voltage source 30 formed by the third outer conductor L3 and the neutral conductor N.

The AC voltages U1, U2, U3 of the voltage supply device 27 are not in phase, but out of phase with each other. In particular, the amount of phase shift between the alternating voltages U1, U2, U3 is equal in each case. If the phases of the 3-phase alternating voltage network are used, then the amount of the phase shift between in each case two alternating voltages U1, U2 or U2, U3 or U1, U3 is 120 ° in each case.

As an alternative to the preferred embodiments, it is also possible to use only a single phase of the AC voltage network and to generate at least one additional AC voltage phase-shifted by a phase shifter circuit. As a result, however, the power factor adjustment of the lighting device 15 be reduced to the AC voltage provided by the network. Therefore, it is preferred that the phase-shifted AC voltages already provided by the network in the voltage supply device 27 to use.

In all exemplary embodiments, the alternating voltages U1, U2, U3 used have the same frequency and the same amplitude. These are preferably alternating voltages U1, U2, U3 with a sinusoidal profile. If the Phases of the 3-phase AC network are used, the frequency is 50 or 60 Hz and the amplitude about 325 volts.

The power supply device 27 also has a rectifier circuit 31 on. The rectifier circuit 31 is preferably designed as a pure diode circuit. For each in the power supply 27 existing AC voltage source are preferably two diodes present (embodiments according to the 1 to 3 ). Alternatively, in a noninventive embodiment, a full-bridge rectification with four diodes each may be provided for each AC voltage source ( 4 ).

In the embodiments according to the 1 to 3 are connected to the power supply 27 a first supply line 38 , a second supply line 39 and a reference line 40 connected. The reference line 40 may be connected to ground M in some embodiments. In the embodiments described herein, the reference line 40 to the neutral conductor N of the alternating voltage sources 28 . 29 . 30 connected. The other potential of the alternating voltage sources 28 . 29 . 30 is each a first diode 41 with the first supply line 38 and via a respective second diode 42 the rectifier circuit 31 with the second supply line 39 connected. The cathodes of the first diodes 41 are with the first supply line 38 and the anodes with the respectively associated AC voltage source 28 . 29 . 30 connected. Conversely, the anodes are the second diodes 42 with the second supply line 39 and the cathodes with the respective associated AC voltage source 28 . 29 . 30 connected. The positive half-waves of the alternating voltages U1, U2, U3 are therefore on the first supply line 38 on, while the negative half-waves of the AC voltages U1, U2, U3 on the second supply line 39 issue. Thus, at the first supply line 38 a pulsating first supply voltage V1 based on the positive half-waves and on the second supply line 39 Based on the negative half-waves of the AC voltages U1, U2, U3, a second supply voltage V2 each with respect to the reference line 40 generated.

The power supply device 27 is in the embodiments according to the 1 to 3 identically designed. In a modification to this, the power supply device not according to the invention 27 according to 4 for each AC source 28 . 29 . 30 two first diodes each 41 and two second diodes 42 on. Both connections of a respective AC voltage source 28 . 29 . 30 each have a first diode 41 with the supply voltage line 38 and via a respective second diode 42 with the reference line 40 connected. The reference line 40 is not connected to ground M in this case. According to the embodiment not according to the invention 4 is only a single supply line 38 with a connected light source string 17 intended. Between this supply line 38 and the reference line 40 is the pulsating supply voltage V1 on.

The tax code 20 for each light source string 17 is adapted to the number of current-carrying lamp groups 18 to vary depending on the course of the respective supply voltage V1, V2. As a result, a phase current IS1, IS2, ie the current consumption of the relevant light source strand 17 , adapted to the course of the respectively applied pulsating supply voltage V1, V2, and thus a power factor matching high quality can be achieved.

At the in 1 illustrated embodiment, the control circuits 21 each via a branch line 22 parallel to the associated light source group 18 connected. Through the branch line 22 and the control circuit 21 a branch current IA _{i flows} with i = 1 to n, if n branch lines 22 or control circuits 21 or lighting groups 18 available. In the embodiments described herein, a control circuit 21 interrupt or allow the branch current IA _i . For this purpose, each control circuit 21 a controllable control switch 45 on ( 5 and 6 ). The control switch 45 can be switched between a conducting and a blocking state. In the conducting state is a current flow through the branch line 22 possible.

When the control circuits 21 parallel to the respective assigned lighting group 18 are switched, the associated lighting group 18 by closing the control switch 45 in the branch line 22 bridged or shorted. As a result, no current flows through the light source group 18 but the entire stream flows through the branch line 22 and the control circuit 21 , In this way, the number of current-carrying lamp groups 18 and consequently the relevant phase current IS1, IS2 to the course of the associated light source strand 17 adjacent supply voltage V1, V2 can be adjusted.

Furthermore, in the embodiment according to 1 in series with the lighting groups 18 a current limiting device 44 be switched to the string current IS1, IS2 through the light source strand 17 limit if all branch lines 22 are interrupted, so the respective control switch 45 lock. The current limiting device 44 can one Resistor or a current sink 46 be as they are in the control circuits 21 is used.

In other embodiments ( 2 to 4 ) are the branch lines 22 in series with each associated with an illuminant group 18 connected. The branch lines 22 connect one output at a time 18a the assigned lighting group 18 with the reference line 40 , As an exit 18a is the connection of the light source group 18 referred to, which is based downstream of the string current IS1, IS2. For a group of bulbs 18 with semiconductor lights is the output 18a associated with the cathode side of the semiconductor lamps.

In the arrangement of a control circuit 21 in series with a respective assigned lighting group 18 can be adjusted by setting or limiting a branch current IA _i through the branch line 22 Number i are influenced, whether in the current direction of the string current IS1, IS2 downstream of this branch line 22 with the number i located light source groups 18 are current-carrying, or how large of these groups of light sources 18 flowing electricity is. For example, via a branch line 22 and the control circuit disposed therein 21 a short to the reference line 40 produced, are in the flow direction of the phase current IS1, IS2 downstream arranged light emitting groups 18 no current flowing through.

The branch currents IA _i (i = 1 ... n) through the branch lines 22 with the numbers i = 1 to n are via the respective control circuit 21 influenced and can in the different branch lines 22 be different.

In the 5 and 6 is schematically the structure for a control circuit 21 the tax code 20 illustrated. The embodiments of the control circuits 21 refer to the embodiments of the lighting device 15 according to the 2 to 4 ,

The control circuit 21 , in the current direction of the phase current IS1, IS2 at the end of the last group of lamps 18 (nth group of bulbs 18 ) can be arranged without control switch 45 be executed. An interruption of this branch line 22 not necessary. Otherwise, in every other branch line 22 (i = 1 to n - 1) each have a control switch 45 available.

Every control circuit 21 has, for example, a current sink 46 to adjust the through the branch line 22 flowing branch current IA _i (i = 1 ... n). The current sink 46 is in series with the control switch 45 switched if it exists. In the connection of the branch lines 22 to the reference line 40 is a resistor arrangement 47 consisting of several series resistors Rx, Ry, Rz. The number of series resistances Rx, Ry, Rz corresponds to the number of control circuits 21 , The series resistors Rx, Ry, Rz are connected in series with each other and one end of this series circuit is connected to the reference line 40 connected. The one, last series resistor Rz is between the last branch line 22 with the number n and the reference line 40 connected. The other series resistors Rx, Ry are each between two immediately adjacent branch lines 22 with consecutive numbers i - 1 and i (i = 1 to n).

The control switch 45 and / or the current sink 46 are controlled depending on an electrical size. As electrical size of the current sink 46 for example, at the output of the same branch line 22 and therefore the at the in the connection of the branch line 22 to the reference line 40 existing series resistors Rx, Ry, Rz respectively applied reference voltage Ux, Uy, Uz for setting the relevant branch current IA _i transmitted.

The respective reference voltage Ux, Uy, Uz at the connection node of the adjacent branch line 22 and the series resistance Rx, Ry, Rz is in the embodiment after 5 used for the switching signal for the control switch 45 to generate. This is for a control switch 45 the branch line 22 with the number i for i = 1, 2, 3,..., n-1 a reference voltage Ux, Uy, Uz of the subsequent branch line 22 with the number i + 1 used when the branch lines 22 consecutively numbered from 1 to n in the flow direction of the phase current IS1, IS2. In the last branch line n example is - as stated - no control switch 45 ,

Is the branch current IA _{i + 1} through the immediately downstream with respect to the current direction of the phase current IS1, IS2 branch line 22 with the number i + 1 sufficiently large, then the control switch 45 the upstream adjacent control circuit 21 in the branch line 22 opened with the number i. As a result, adapted to the pulsating profile of the respective supply voltage V1, V2, the number of current-carrying lamp groups 18 be increased sequentially with increasing supply voltage and again be reduced sequentially with decreasing supply voltage. To reduce the current-carrying light-emitting groups 18 can the control switch 45 be correspondingly closed again when the reference voltage in the downstream immediately adjacent branch line 22 has fallen below a threshold.

The embodiment of the control arrangement 20 in 6 essentially corresponds to the 5 so that reference may be made to the above description. In contrast to the embodiment according to 5 it is according to the embodiment 6 provided, instead of the reference voltages Ux, Uy, Uz another electrical variable for switching the control switch 45 to use. For this example, the group output voltage UA _n , UA _n-1 can be used, which at the output 18a the downstream in the flow direction of the strand current IS1, IS2 located downstream lighting group 18 is applied. This is for a control switch 45 the branch line with the number i a group output voltage UA _{i + 1 of} the subsequent branch line 22 with the number i + 1 used when the branch lines 22 consecutively numbered from 1 to n in the flow direction of the phase current IS1, IS2. The operation is basically the same as in the embodiment of FIG 5 ,

Based on 7 and 8th the operation of the embodiments according to the 1 to 3 the lighting device 15 explained. In 7 schematically shows the course of the three alternating voltages U1, U2, U3. The first AC voltage U1 is shown by a solid line, the second AC voltage U2 is dashed and the third AC voltage U3 is shown in phantom. Through the rectifier circuit 31 will be on the first supply line 38 the first supply voltage V1 and the second supply line 39 formed the second supply voltage V2. The two supply voltages V1, V2 each have a pulsating course and are in 7 dotted illustrated.

As can be seen, the alternating voltages U1, U2, U3 are each phase-shifted by the amount of 120 °. The respective positive half-waves are used to form the first supply voltage V1 and the respective negative half-waves to form the second supply voltage V2. Accordingly, the two supply voltages V1, V2 are phase-shifted with respect to each other, wherein a magnitude maximum of the first supply voltage V1 coincides in time with an absolute minimum of the second supply voltage V2. Since the two supply voltages V1, V2 each a light source strand 17 are assigned, thereby a particularly uniform illumination can be achieved.

In 7 is also schematically using the example of the first AC voltage U1, the stepwise increasing and decreasing the first phase current IS1 through the associated first light source strand 17 for a pulse arc of the pulsating first supply voltage V1 exemplified. It is made up of three groups of bulbs 18 in a light source string 17 went out. It should be noted that the number of lamp groups per lamp string 17 can be chosen arbitrarily.

The explanations regarding the process relate to the embodiments according to FIG 2 and 3 , At a first time t1 is determined by the control arrangement 20 the current flow through a first group of lamps 18 authorized. At the second time t2 and at the third time t3 in each case a further light source group 18 connected, so that the first phase current IS1 gradually increases in accordance with the rising first supply voltage V1. Subsequently, in reverse order, the number of current-carrying lamp groups 18 again reduced. At a fourth time t4, the current flow through one of the groups of light sources 18 and at a fifth time t5 by another group of lamps 18 prevented. Finally, at a sixth point in time t6, all the groups of illuminants are again 18 de-energized. Following this, the sequential connection and disconnection for the next pulse arc of the first supply voltage V1-which is based, for example, on a positive half cycle of the second AC voltage U2-begins in the same way.

The same procedure is followed for the second phase current IS2 by the second supply line 39 connected second light source 17 executed with respect to the second supply voltage V2. As a result, the two phase currents IS1, IS2 then arise, adapted to the respective supply voltage V1 or V2, by the respectively relevant light source string 17 as it is in 8th is shown schematically. Due to the selected arrow directions in the figures, in which the actual technical flow direction of the second phase current IS2 is illustrated, shows 8th the current profile for -IS2, ie the negative (multiplied by -1) time-dependent value of the second phase current IS2.

Are the control circuits 21 in series with the respectively assigned lamp group 18 switched ( 2 to 4 ), the lamp groups can be switched one after the other only in a predetermined order in the marked flow direction of the phase current IS1, IS2 and switched off in the reverse order. In contrast, according to the embodiment 1 the possibility of the order of activation and deactivation of the lighting groups 18 to choose freely.

In 9 is the first supply voltage V1 for the embodiment according to 4 of the lighting device 15 illustrated. By the full-bridge rectification of the rectifier circuit used there 31 is the regularity of the first supply voltage V1 and corresponding to the current flow IS1 through the light source strand 17 even bigger. The half-waves of the alternating voltages U1, U2, U3 generating the supply voltage V1 are also illustrated schematically.

Each light source string 17 Optionally, a capacitor circuit 50 with a capacitor 51 be assigned, which is merely exemplary in 6 is shown, however, in all embodiments of the lighting device 15 can be used. The capacitor circuit 50 has a first connection 50a , a second connection 50b and a third connection 50c , All three connections 50a . 50b . 50c are with a light source string 17 connected, being between two connections 50a . 50b . 50c the capacitor circuit 50 at least one group of bulbs 18 is interposed.

The capacitor circuit 50 has at least one controllable switch and in the embodiment a controllable first switch 52 and a controllable second switch 53 on. In series to the condenser 51 and according to example between the first switch 52 and the capacitor 51 is a diode 54 switched, whose cathode is connected to the capacitor 51 connected is. The series connection from the first switch 52 and the diode 54 is between the first port 50a and the third port 50c the capacitor circuit 50 arranged. The second connection 50b the capacitor circuit 50 is over the second switch 53 with the cathode of the diode 54 and the capacitor 51 connected.

By closing the first switch 52 can the capacitor 51 charged, provided the second switch 53 is open. Will be the second switch 53 closed, is the capacitor 51 at least in parallel to a group of bulbs 18 connected. He can discharge himself to the capacitor 51 connected in parallel, at least one light source group 18 over the through the capacitor 51 supplied capacitor current for a short time to feed. A controller, which can be built by discrete components or by a microcontroller, the two switches 52 . 53 adapted to the course of the relevant supply voltage V1, V2 are opened and closed. Thus, charging the capacitor 51 be in the range of the magnitude maximum of the relevant supply voltage V1, V2, while the capacitor 51 discharges when the amount of supply voltage has a minium. With the help of this capacitor circuit 50 Thus, further minimizing the flicker can be achieved.

In the description of the figures were exemplary in each light source strand 17 three groups of bulbs 18 illustrated. The number of lamp groups 18 may deviate from this also be larger or smaller. Preferably, at least three and at most five to seven bulbs groups 18 per light source string 17 connected in series. Five or six groups of bulbs 18 per light source string 17 are considered to be particularly advantageous in terms of the component cost and a homogenization of the lighting.

A particularly uniform luminous impression can also be achieved by a suitable arrangement of the lamp groups or of the individual lamps, which are optionally provided with an additional diffuser.

The invention relates to a lighting device 15 with a lighting arrangement 16 , The lighting arrangement 16 has two light sources 17 on. In every light source 17 are several groups of bulbs 18 connected in series. Each group of bulbs 18 is a control circuit 21 a control arrangement 20 assigned. For every light source 17 is a control arrangement 20 available. About the control arrangement 20 can the number of current-carrying lamp groups 18 adapted to the course of a light at the respective strand 17 applied supply voltage V1, V2 increased, maintained or reduced. This allows a current IS1, IS2, by a light source strand 17 is taken in total, depending on the number of current-carrying lamp groups 18 be increased and decreased. A power supply device 27 serves to provide the at least one supply voltage V1, V2. For this purpose, the power supply device generates 27 from at least two and preferably three mutually phase-shifted alternating voltages U1, U2, U3 at least one pulsating supply voltage V1, V2 by means of a rectifier circuit 31 , The rectifier circuit 31 generates from the positive half-waves of all AC voltages U1, U2, U3 a pulsating first supply voltage V1 to a first supply line 38 and from the negative half-waves of all AC voltages U1, U2, U3 a pulsating second supply voltage V2 to a second supply line 39 , A light source string 17 is to the first supply line 38 and another light source string 17 is to the second supply line 39 connected.

LIST OF REFERENCE NUMBERS

15

lighting device

16

Lamp positioning

17

Lamp strand

18

Lamp group

18a

Output of the light source group

19

Lamp

20

control arrangement

21

control circuit

22

branch line

27

Power supply means

28

first AC voltage source

29

second AC voltage source

30

third AC voltage source

31

Rectifier circuit

38

first supply line

39

second supply line

40

reference line

41

first diode

42

second diode

44

Current limiting means

45

control switch

46

current sink

47

resistor arrangement

50

capacitor circuit

50a

first connection of the capacitor circuit

50b

second terminal of the capacitor circuit

50c

third connection of the capacitor circuit

51

capacitor

52

first switch

53

second switch

54

diode

IA _i

Branch current through branch line number i

IS1

first phase current

IS2

second phase current

L1

first outer conductor

L2

second outer conductor

L3

third outer conductor

M

Dimensions

N

neutral

Rx

series resistance

Ry

series resistance

March

series resistance

t1

first time

t2

second time

t3

third time

t4

fourth time

t5

fifth time

t6

sixth time

U1

first alternating voltage

U2

second AC voltage

U3

third alternating voltage

U _n-1

Group output voltage

U _n

Group output voltage

Ux

reference voltage

uy

reference voltage

Uz

reference voltage

V1

first supply voltage

V2

second supply voltage

Claims (10)

Lighting device ( 15 ), with a lighting arrangement ( 16 ), the two illuminant strands ( 17 ) each having a plurality of light-emitting groups connected in series with one another ( 18 ), with a voltage supply device ( 27 ) containing at least two AC sources ( 28 . 29 . 30 ), each of which provides an alternating voltage (U1, U2, U3) which are phase-shifted relative to one another, with a rectifier circuit ( 31 ) connected to the AC sources ( 28 . 29 . 30 ) is connected, the positive half-waves and / or the negative half-waves of all alternating voltages (U1, U2, U3) a pulsating supply voltage (V1, V2) on each supply line ( 38 . 39 ), wherein the supply line ( 38 . 39 ) to an associated light source string ( 17 ) is connected, each illuminant strand ( 17 ) a control arrangement ( 20 ) associated with a plurality of control circuits ( 21 ), and wherein each control circuit ( 21 ) via a respective branch line ( 22 ) with a respective assigned lighting group ( 18 ) is connected in series or parallel thereto, the rectifier circuit ( 31 ) from the positive half-waves of all alternating voltages (U1, U2, U3) a pulsating first supply voltage (V1) to a first supply line ( 38 ) and from the negative half-waves of all AC voltages (U1, U2, U3) a pulsating second supply voltage (V2) to a second supply line ( 39 ) and wherein a light source strand ( 17 ) to the first supply line ( 38 ) and another light source string ( 17 ) to the second supply line ( 39 ) connected. Lighting device according to claim 1, characterized in that the rectifier circuit ( 31 ) three first diodes ( 41 ) and three second diodes ( 42 ), wherein one of the two terminals of each AC voltage source ( 28 . 29 . 30 ) via one of the first diodes ( 41 ) with the first supply line ( 38 ) and in each case via one of the second diodes ( 42 ) with the second supply line ( 39 ) connected is. Lighting device according to one of the preceding claims, characterized in that the control circuit ( 21 ) is arranged to divert the branch stream (IA _i ) through one or more of the branch lines ( 22 ) to influence. Lighting device according to one of the preceding claims, characterized in that three alternating voltage sources ( 28 . 29 . 30 ) are present whose AC voltages (U1, U2, U3) are each phase-shifted by the amount of 120 ° relative to each other. Lighting device according to one of the preceding claims, characterized in that each AC voltage source is formed by a respective outer conductor (L1, L2, L3) and a neutral conductor (N) of a three-phase alternating voltage network. Lighting device according to one of the preceding claims, characterized in that the at least one control arrangement ( 20 ) is adapted to the number of current-carrying groups of lamps ( 18 ) of the associated light source string ( 17 ) adapted to the amount of the pulsating supply voltage (V1, V2) of the relevant supply line ( 38 . 39 ) to vary. Lighting device according to one of the preceding claims, characterized in that at least several of the control circuits ( 21 ) a controllable control switch ( 45 ), which in the branch line ( 22 ) is arranged and switchable between a conductive and a blocking state. Lighting device according to claim 7, characterized in that the switching state of the controllable control switch ( 45 ) in a branch line ( 22 ) of an electrical variable (Ux, Uy, Uz) in and / or on the immediately adjacent branch line ( 22 ) depends. Lighting device according to one of the preceding claims, characterized in that at least one capacitor circuit ( 50 ) with a capacitor ( 51 ) and at least one controllable switch ( 52 . 53 ), wherein the capacitor circuit ( 51 ) to an associated supply line ( 38 . 39 ) connected. Lighting device according to claim 9, characterized in that the capacitor circuit ( 50 ) is adapted to the capacitor ( 51 ) when the pulsating supply voltage (V1, V2) at the associated supply line ( 38 . 39 ) exceeds a predetermined amount, and which is adapted to the capacitor via at least one light source ( 19 ) of a lighting group ( 18 ) when the pulsating supply voltage (V1, V2) at the associated supply line ( 38 . 39 ) falls below a predetermined further amount.

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