DE102012006316A1 - LED illumination device for e.g. 230V public electricity main of incandescent lamp in airplane, has short circuit arrangements controlled in super dimming, so that LED subsets are deactivated for partial period of shaft portion - Google Patents

Abstract

The device (1) has multiple LEDs forming a total chain (9). The chain of LEDs is switched into switching states by a control device (10) i.e. microcontroller, based on an amplitude of a power supply voltage. The switching states are changed twice in a normal operation of the device. Short circuit arrangements (8a, 8b) bypass the LEDs of the total chain. The control device is formed such that the short circuit arrangements are controlled in super dimming, so that LED subsets of the total chain are deactivated for a partial period of a shaft portion. An independent claim is also included for a method for operating a LED illumination device.

Description

The invention relates to an LED lighting device for an AC power supply with a plurality of LEDs, which form an overall chain, wherein the LEDs are distributed in LED subgroups, wherein in the LED lighting device, a supply voltage having varying amplitude, wherein the supply voltage formed by repeating wave sections is. The invention also relates to a method for operating the LED lighting device.

LED lighting has advantages over conventional types of lighting in terms of high energy efficiency and low heat generation. Comparing the energy demand between LED lighting and lighting with conventional light sources, such. B. incandescent lamps, so only a fraction of the energy must be expended in the LED lighting to produce the same light flux in a visible to the human area.

In contrast, the requirements for power supplies for LED lighting are significantly higher, compared to power supplies of incandescent lamps. In particular, in AC power supplies incandescent lamps can be supplied with the AC voltage directly, as far as the amplitude of the AC power supply is adapted to the respective bulb. In contrast, LED lighting usually have to be operated in a comparatively small working window for the supply voltage. The working window is chosen so that the supply voltage must be above a threshold voltage, which is needed for LEDs to start lighting. On the other hand, the supply voltage must be operated below an upper limit voltage, so that the current flow through the LEDs is not too high and the LEDs are destroyed by heat. Thus, the use of LED lighting also requires the development of power supplies that work with the LED lighting.

The publication DE 20 2011 105 404 U1 includes various options for supplying power to LEDs, it being also noted that light emitting diodes can be powered by an AC voltage source, wherein between the LEDs with any series resistors a bridge rectifier is arranged so that the LEDs are supplied with pulsating current.

The invention has for its object to provide an LED lighting device, which is adapted for an AC power supply. The invention is also based on the object of proposing a method for operating the LED lighting device.

This object is achieved by a lighting device with the features of claim 1 and by a method for operating the LED lighting device having the features of claim 13. Preferred or advantageous embodiments of the invention will become apparent from the dependent claims, the following description and the accompanying drawings.

In the context of the invention, an LED lighting device is disclosed, which is designed for an AC power supply. The AC power supply can be, for example, a public power grid with an effective mains voltage of 230 volts and a grid frequency of 50 hertz. Particularly preferably, the AC voltage supply has an effective voltage of 115 volts and a mains frequency between 400 hertz and 800 hertz, such an ac voltage supply being provided, for example, in an aircraft.

The LED lighting device has a plurality of LEDs (light-emitting diode / light emitting diode), which form an overall chain. The multiple LEDs can z. B. be designed as white LEDs, red LEDs, green LEDs or blue LEDs or as a mixture thereof. In a specific embodiment, all LEDs of the overall chain have the same color, in particular all the LEDs are designed as white LEDs. The overall chain describes an electrical connection of the plurality of LEDs, wherein the entire chain is powered by a common, in particular two-pole connection with energy. Within the overall chain, the plurality of LEDs may be arranged electrically parallel or serially to one another or in a hybrid form.

The LEDs are organized or distributed in LED subgroups, with at least one LED in each LED subgroup. In the smallest embodiment of the invention, exactly one LED is thus arranged in each LED subgroup, in a preferred embodiment of the invention a plurality of LEDs is arranged in each LED subgroup. Within the LED subgroup, the LEDs can be arranged electrically parallel or serially or in a mixed form with each other. Each LED subgroup also has its own, in particular two-pole, connection to the power supply.

Due to the AC voltage supply is a supply voltage with varying amplitude. In one possible embodiment of the invention, the LED lighting device comprises an optional line filter, a rectifier and a PFC module, which together consist of the AC power supply generate the supply voltage with alternating amplitude. In a special embodiment, the supply voltage is designed as a rectified AC voltage, in particular rectified sinusoidal AC voltage.

It is provided that the curve of the supply voltage is formed by a repeating shaft section. Is the supply voltage z. B. formed as the rectified, sinusoidal AC voltage, the shaft portion is formed in each case as a sinusoidal half-wave.

The LED lighting device comprises a control device for controlling the entire chain, wherein the control device is designed to switch the overall chain into at least two circuit states. The at least two circuit states differ by the forward voltage of the whole chain.

Under the forward voltage - also called forward voltage - is in particular the threshold voltage understood, which must be present so that the actively switched in the respective switching state LEDs of the overall chain to light up.

The different forward voltages of the switching states are achieved by switching the LED subgroups in series or in series or in parallel, depending on the switching state, in order to change the forward voltage. For example, if you switch two LED subgroups with only one LED at a forward voltage of 3.4 volts in series, the common forward voltage is 6.4 volts. If these are switched in parallel, the forward voltage is only 3.4 volts.

The LED illumination device thus makes it possible for the forward voltage of the overall chain to be flexibly adaptable to the changing amplitude of the supply voltage.

In this way, it can be achieved in one possible embodiment that all the LEDs of the overall chain are simultaneously operated with respect to the voltage level in an acceptable working window, in particular without causing losses due to series resistances. In alternative embodiments of the invention, it is implemented that a subset of the LEDs is operated with respect to the voltage level in an acceptable working window and another subset of the LEDs is switched off at least temporarily.

In particular, the control device is designed to control the overall chain such that the circuit state is activated, which has the highest forward voltage, wherein the forward voltage is at the same time less than or equal to the current supply voltage. It is thus preferably always selected the circuit state, which makes the best use of the supply voltage. This mode of operation prevents overheating of the LEDs due to excessive voltage and at the same time operates the LEDs in an energy-efficient range.

For example, the control device is designed as a programmable, in particular digital data processing device. In particular, the controller is implemented as a microcontroller, DSP or FPGA. This implementation has the advantage that the control of the overall chain can be flexibly adapted by programming the data processing device.

The at least two circuit states are in particular taken regularly and / or on average at least once during one of the shaft sections. In particular, the circuit states are changed at least twice during normal operation of the LED lighting device during one of the shaft sections. Thus, on a rising edge, one of the circuit states is regularly changed to another one of the circuit states, and the switching states are changed in the opposite direction on a falling edge of the shaft section. This embodiment emphasizes that the adaptation of the circuit states is implemented highly dynamically, namely during the repeating wave section. In particular, it is not a static change in the circuit state, which extends over several shaft sections. In this way, the overall chain during a shaft section is preferably adjusted on average by at least two, preferably three and in particular at least four circuit state changes to the instantaneous value of the supply voltage.

According to the invention, the LED lighting device has a short-circuit arrangement which is designed to bridge the LED subgroups of the overall chain, in particular such that a switchable, electrical bypass to the LED subgroups of the overall chain is formed. The short-circuit arrangement may be formed as an integral part of the overall chain and thus form an internal bypass or be formed as an additional component as an external bypass. By the short circuit arrangement is achieved in particular that a supply current for the LED subgroups of Overall chain is passed past the LED subgroups of the overall chain, in particular such that no supply current flows through the LED subgroups of the overall chain. By this measure, in particular all LED subgroups of the overall chain are deactivated at the same time.

The control device is designed to control the short-circuit arrangement in a super dimming operation of the LED lighting device in such a way that the LED subgroups of the overall chain are bridged for at least a subperiod of the wave section and thus deactivated. In particular, the subset of the LED subgroups is bypassed by the short circuit arrangement, which are active in the current circuit state. However, it is provided in particular that for a different period of the same shaft section, the short circuit arrangement is deactivated, so that the supply current can flow through the LED subgroups of the overall chain and at least a subset of the LED subgroups shines. The shaft section thus has the sub-period with deactivated LED subgroups and a period in which at least a subset of the LED subgroups lights up.

Particularly preferably, the activation of the short-circuit arrangement is synchronized with the supply voltage. The synchronization is realized in particular such that, for a selected super dimming operation, the sub-period or sub-periods for each shaft section have the same time length or the same time lengths and occupy the same temporal position or position within the shaft section or the same temporal positions or Occupy positions within the shaft section. In particular, the synchronization is independent and / or unsynchronized with a PWM clock or a switching clock of the PFC module. This preferred embodiment ensures that the LED lighting device in the super dimming operation emits the same brightness in each wave section, thus avoiding flicker, as could happen if the time length and / or the time position of the sub-period within the successive Shaft sections would vary arbitrarily.

It is a consideration of the invention to achieve a dimming, ie a reduction in the brightness of the plurality of LEDs, the LED subgroups or the entire chain by short-circuiting all active LED subgroups of the overall chain within a wave section for a sub-period and thus disabled so that the whole chain is disabled in its entirety.

Conventionally, lighting devices are dimmed by reducing the voltage. This is not easily possible with LEDs, since a simple reduction of the voltage amplitude below the forward voltage would not lead to a dimming behavior, but to a switching off of the LEDs. Due to the fact that LEDs react very quickly and in addition the frequent switching on and off of LEDs does not reduce their life-relevant practical relevance, the invention makes use of the possibility of not reducing the brightness of the entire chain by reducing the brightness of a single LED. but by a temporary deactivation of the LED subgroups to realize.

It is provided in particular that the sub-period overlaps with a period of the shaft section in which the supply voltage is greater than the forward voltage, in particular the forward voltage of all possible or all switching states used in the overall chain. This training again underlines the inventive idea to activate the whole chain in a sub-period in which this would be activated in normal operation.

In a preferred embodiment of the invention, the at least one sub-period overlaps with an initial section and / or with an end section of the shaft section. If the shaft section is designed as a sinusoidal half-wave as described above, then it has an ascending and a descending edge and two zero crossings. In the region of the zero crossings, the supply voltage is less than the forward voltage of that switching state of all possible or used switching states, which has the lowest forward voltage. Thus, it is particularly preferable that the short-circuiting arrangement is activated as long as the supply voltage is smaller than the lowest possible forward voltage. This sub-period is also referred to as the activation period of the short-circuit arrangement. However, it is proposed to extend this activation period of the short-circuit arrangement in order to maintain the deactivated state of the overall chain on the rising edge longer and / or to start earlier in the falling edge. Both alternatives reduce the time during which the entire chain lights up, thus reducing the brightness of the entire chain and thus dimming the LED lighting device.

Optionally additionally, the LED lighting device has a controllable current source, wherein the control device is designed to control the current source in a dimming operation, so that a supply current for the entire chain is reduced to a dimming supply current. In a special embodiment, it can be provided that the dimming supply current is less than 20%, preferably less than 10% and in particular less than 5% of the supply current is formed in normal operation. For example, the power source may be formed as the previously described PFC module. It has been found that such dimming operation is possible to a certain extent; Below a certain limit, however, it is to be feared that the power supply will become unstable, so that the active LEDs of the LED subgroups begin to flicker and thus a proper dimming operation is no longer ensured.

Although with the inventive design of the LED lighting device is possible to start the super dimming operation already at 100% of the supply current, but it is preferred to reduce the supply current as far as possible on the dimming supply current via the controllable current source and a weather dimming on the described Implementation of the short-circuit arrangement implement.

In a preferred development of the invention, the LED lighting device has a current sink device which is connected in series (or in series) with the overall chain. The supply voltage and the supply current are applied to the current sink device. The current sink device is designed to control a chain current for the entire chain, so that the time profile of the supply current is synchronized with the time profile of the supply voltage or the time profile of a mains voltage of the AC voltage supply. This development of the invention is based on the consideration that by changing the circuit states, the changing amplitude of the supply voltage and the activation or deactivation of the short-circuit arrangement would flow without further measures a very uneven current through the entire chain. Due to the uneven chain current, a similarly uneven mains current would be drawn from the AC power supply on the one hand, and on the other hand, a very uneven brightness would be output at the several LEDs. In order to reduce these effects, the current sink device ensures that the chain current is always selected so that the supply current is optionally synchronized with the time profile of the supply voltage or the time profile of the mains voltage of the AC voltage supply.

The mentioned time profiles can be introduced in the current sink device as a reference variable. The current sink device has z. B. a controllable internal resistance whose height is calculated by the quotient of the differential voltage between the supply voltage or mains voltage and the current forward voltage of the entire chain divided by the desired supply current. In particular, the current sink device is controlled or regulated such that a power factor of the LED lighting device remains high.

It is particularly preferred that the supply current or chain current available on the basis of the activated short-circuit arrangement is destroyed by the current sink device or converted into heat in order to keep the power factor of the LED lighting device high.

Considered in an overall concept, the LED lighting device is thus first dimmed by the control of the controllable current source by the control device by reducing the supply current and thus the chain current. If further dimming is no longer possible by reducing the supply current or chain current, the short circuit arrangement is additionally activated in order to deactivate the entire chain during a subperiod of the shaft section. In order to keep the power factor of the LED lighting device as high as possible in spite of this activation, the supply current or chain current available or excess during the activation of the short-circuit arrangement is converted into heat by the current sink device. Since at the same time the dimming of the entire chain takes place by reducing the supply current, the losses due to the current sink device are low.

In a preferred embodiment of the invention, the super dimming operation is infinitely adjustable, d. that is, the sub-period may, for example, extend over a time range of 1% to 99% of the entire period of the shaft portion.

In an alternative embodiment of the invention, it is provided that a switching state or a switching state change per shaft section can be saved by the super dimming mode.

In a first possible circuit configuration of the invention, the LED subgroups are reorganized when the circuit state of the interconnection changes. In a lower circuit state of the overall chain, at least two LED subgroups are electrically connected in parallel with one another, so that the overall chain has a first forward voltage in the lower circuit state than one of the at least two switching states. A parallel connection of two LED subgroups in the overall chain is present in particular when the poles of the same name of the LED subgroup are connected to one another are connected. in the reorganization of the interconnection of the entire chain, which is controlled by the controller, the entire chain is switched to a higher circuit state, the at least two LED subgroups are connected in series with each other, so that the entire chain in the higher circuit state than one of the at least two circuit states has a second forward voltage which is greater than the first forward voltage.

In a preferred embodiment of the invention, the circuit device is designed to interconnect the overall chain in at least three different circuit states, wherein the total chain in each case has a different forward voltage in the at least three circuit states. The transition from one to a next circuit state is each time converted by a transition from a lower circuit state to a higher circuit state (or in the opposite direction). The terms "lower circuit state" and "higher circuit state" thus refer to a relative change in the circuit states, the at least three circuit states, however, refer to absolute circuit states.

In a second circuit configuration of the invention, a plurality of LED subgroups are arranged serially with respect to one another so that they form an LED strand or at least one LED strand. In the case of serial connection of the LED subgroups, the LED subgroups are switched one after the other or one after the other. This type of circuit is also referred to as a series circuit. In addition, it is proposed to provide a plurality of short-circuit devices, which are each designed to bridge one of the LED subgroups in the LED string. The short-circuit devices are preferably designed to be switchable or controllable, these being activated as a function of their condition and bridging the associated LED subgroup short-circuited or bypassed or inactive, so that a current can flow or flows through the LED subset. Preferably, one of the short-circuit devices is assigned to each of the LED subgroups in the LED string. The control device is designed to control the short-circuit devices, so that the state of the short-circuit devices can be changed from active to inactive and in the opposite direction. The control of the short-circuit device is carried out such that the LED string is displaceable in the at least two circuit states, wherein the at least two circuit states differ by the forward voltage of the LED string and thus the total chain.

In one possible development of the invention, the short-circuit devices as a whole form the short-circuit arrangement. In a further possible development of the invention, the overall chain has a plurality of such LED strands, wherein the LED strands are electrically connected in parallel to each other.

In a third circuit configuration of the invention, the LED lighting device comprises a plurality of series switching devices, which are designed in particular as controllable breaker switches, wherein a series switching device and an LED subgroup together form an LED assembly. The series switching device is formed in the LED assembly so that a current flow through the respective LED subgroup can be interrupted. In particular, the series switching device is arranged in series with the LED subgroup with respect to an input and an output of the LED package, or with respect to two poles of the LED package. If the series switching device is opened, the current flow through the LED subgroup and through the LED module is interrupted. The LED lighting device comprises a plurality of such LED assemblies, which are connected in series - also called row - are connected, so that an LED column is formed, wherein the plurality of LED assemblies form LED rows to the LED column. In the simplest embodiment of the circuit configuration with m LED modules, which are organized in an LED column, an m × 1 matrix is formed in this way. In further embodiments of the circuit configuration, the overall chain has a plurality of LED columns, in particular n LED columns, so that an m × n (rows × columns) matrix is formed. The arrangement of the LED assemblies in the respective matrix is to be understood in particular as a logical or electrical arrangement, in the actual spatial distribution, the LED assemblies may also be arranged like a matrix, but may also take any other arrangement. In the latter case, corresponding connection lines must be led to the LED modules.

In the third circuit configuration, the LED lighting device, in particular the overall chain, comprises a plurality of short-circuit devices, wherein the LED lines are each assigned one of the short-circuit devices and wherein the short-circuit device is designed to bridge the LED module or modules in the LED line ,

In the simplest embodiment of the further circuit design described above, such a short-circuit device forms a bypass to that in the respective LED Row arranged LED assembly. In particular, the series switching device of the LED module is bridged by the short-circuit device, in particular the bypass. As far as several LED columns are provided, all LED modules in the associated LED row are bridged by a common short-circuit device.

The control device is designed in the third further circuit configuration for driving the short-circuit devices and the series-switching devices in order to put the entire chain in the at least two circuit states. In one possible development of the invention, the short-circuit devices as a whole form the short-circuit arrangement.

In a preferred embodiment of the invention, in particular in connection with the second and the third circuit configuration, the control device is designed to control the overall chain so that the entire chain can be placed in several variants of a circuit state. The different variants of a circuit state have the same forward voltage of the entire chain, the selection of the active, ie current-carrying LED subgroups, however, varies from variant to variant. If all LED subgroups are considered as elements of a set, the active LED subgroups form as elements a (real) subset of the set in a switching state. In a variant of the same circuit state, a second (true) subset of the set is formed with active LED subgroups, the first and second subset being unequal.

The advantage of the multiple variants of a switching state is that the control device is designed, for example, such that in a preferred operating mode all or most of the LEDs of the overall chain can be activated for the same amount of time over a time average. Another advantage of the different variants is that LEDs can be activated at different positions. Thus, even with a larger number of deactivated LEDs in the overall chain by using the different variants in the time average, a uniform illumination can be achieved. Optionally, the variants can also be used to activate LED subgroups with different colors depending on a desired overall color of the overall chain, without changing the forward voltage of the overall chain.

Another object of the invention relates to a method for operating the LED device according to one of the preceding claims and / or as has been previously described.

Further features, advantages and effects of the invention will become apparent from the following description of a preferred embodiment of the invention and the accompanying figures. Showing:

1 a schematic block diagram of an LED lighting device as an embodiment of the invention;

2 a graph illustrating the operation of the LED lighting device in the 1 ;

3 a graph illustrating an improved switching operation of the LED lighting device in the 1 ;

4 a graph illustrating the super dimming behavior of the LED lighting device in the 1 ;

5a , b, c is a schematic representation of a first embodiment of an overall chain of LEDs in the 1 in different switching states;

6a , b, c is a schematic representation of a second embodiment of the overall chain of LEDs in the 1 in different switching states;

7a , b the total chains in the switching states of 6a , b each in a variant of the switching state;

8th a schematic representation of a modification of the overall chain of LEDs in the 6a , b, c, d;

9a , b, c, d a schematic representation of an overall chain of LEDs in the 1 in a circuit state in four different variants;

10a , b is a schematic representation of the overall chain in the preceding 9a , b, c, d in a second circuit state in two different variants;

11 a schematic representation of a modification of the overall chain of LEDs in the 9a , b, c, d.

The 1 shows a schematic block diagram of an LED lighting device 1 which is suitable for operation with an AC power supply 2 is trained. The LED lighting device 1 serves, for example, to illuminate the interior of an aircraft in Passenger area. The LED lighting device 1 is to the AC power supply 2 from which it relates a mains voltage and a mains current. After an entrance 3 in the LED lighting device 1 Optionally follows a line filter 4 , which is formed, interference, which in the AC power supply 2 could be fed back to filter. In particular, it is a low-pass filter, which is formed for example by an interconnection of capacitors and inductors.

The mains filter 4 is a rectifier 5 downstream, which is designed to convert the applied mains voltage or filtered mains voltage in a rectified supply voltage. The rectifier 5 is designed for example as a bridge rectifier. The rectified supply voltage and the rectified supply current is sent to a PFC module 6 which comprises a harmonic filter or a power factor correction filter and a smoothing device, such as a capacitor. In the power correction filter, at least one switching element is arranged, so that the power factor correction filter as a clocked system or the combination of rectifier 5 and PFC module 6 is designed as a switching power supply.

The PFC module 6 provides a supply voltage and a supply current following a current sink device 7 - also called electronic load - to be handed over. The current sink device 7 is designed, regulated or controlled electricity and thus to destroy power by converting it into heat.

Starting from the current sink device 7 become a chain tension and a chain stream over an external short circuit arrangement 8a to an LED overall chain 9 passed with a plurality of LEDs. Alternatively or additionally, the LED overall chain has an internal short-circuit arrangement 8b on.

The short circuit arrangement 8a , b is switchable and bridges the LED overall chain in the activated state 9 so that the plurality of LEDs are disabled.

The LED lighting device 1 also includes a circuit device 10 , which - as shown here - may be formed in one piece or multi-part and which for controlling the LED overall chain 9 and the short circuit arrangement 8a , b is formed. As an input signal, the circuit device receives 14 the chain tension, which also corresponds to the supply voltage. Alternatively, the circuit device receives 10 the supply voltage as the input signal. The circuit device 10 can z. B. be designed as a programmable microcontroller.

The LED overall chain 9 is via the circuit device 10 switchable to different circuit states I, II and possibly III, wherein the circuit states differ by the forward voltage (also called forward voltage) of the LED overall chain. A corresponding control circuit for this type of switching can be realized, for example, with the aid of diodes and transistors. Thus, the forward voltage of the switching state I is smaller than the forward voltage of the switching state II and the forward voltage of the switching state II smaller than the forward voltage of the switching state III. The LED overall chain has at least two switching states I, II. However, at least a third switching state III is advantageous. Under the forward voltage - also called forward voltage - is understood in particular the threshold voltage, which at the LED overall chain 9 must be present, so that in the respective switching state actively switched LEDs of the LED overall chain 9 start to shine.

The 2 shows a half-wave in a schematic graph 13 the chain tension, which also corresponds to the supply voltage. In the graph, the time t is plotted on the x-axis and the amplitude in any units on the y-axis. The circuit device 10 receives as input signal the chain tension or a proportional signal. At the beginning of the half-wave 13 becomes the total LED chain 9 switched on the circuit state I, so that the LED overall chain 9 has a first, low forward voltage. As a result, even with the comparatively low chain tension, the active LEDs of the LED overall chain can 9 be lit up. If the chain tension continues to increase, this in particular exceeds the second forward voltage of the LED overall chain 9 in the circuit state II, the circuit device switches 10 the LED overall chain 9 in the second circuit state II order. Once the chain tension the third forward voltage of the third circuit state III of the LED overall chain 9 has exceeded, is from the scarf processing device 10 the circuit state III is set. On the descending flank of the half wave 13 the process repeats in reverse order. By switching the LED overall chain 9 in the manner described, it is possible to use the forward voltage of the LED overall chain 9 much better to the current chain tension of the half-wave 13 adapt and thus the efficiency and the light duration of the LED overall chain 9 to improve.

The short circuit arrangement 8a , b serves - as shown schematically in the 3 is shown - at the beginning and at the end of the half wave 13 during an activation period K, the total LED chain 9 during which the chain tension is lower than the lowest forward voltage of the circuit states I, II, III. During these periods, the current sink device 7 let a chain current flow, so that the power factor requirements of the LED lighting device 1 continue to be fulfilled. The activation period K is at the beginning and at the end of the half wave 13 ,

In a super dimming operation, the activation period K z. B. by the circuit device 10 controlled magnified, as in the 4 is shown, so that a sub-period KX results in which the short-circuit arrangement 8a or 8b is activated. This will set the time within a half-wave 13 while the LED overall chain 9 lit, reduced. Since the supply voltage has a frequency greater than z. B. 60 Hertz, this deactivation of a human observer is not as flicker, but as a reduction in the brightness of the LED overall chain 9 perceived.

In this way it is possible, a super dimming behavior of the LED overall chain 9 to reach. It is also possible by controlling the short circuit arrangement 8a or 8b the or another sub-period KX in the middle part of the half-wave 8th to lay. For example, the sub-period KX in its entirety more than 10%, 20% or 30% of the duration of the half-wave 13 be. However, the complementary period in which the LED overall chain should be 9 or subsections light up, at least 5%, 10% or 20% of the duration of the half wave 13 be. The available supply current or chain current during the sub-period KX can be determined by the current sink device 7 consumed, so that a power factor of the LED lighting device 1 stays high.

Optionally additionally it can be provided that the supply current or the chain current through the PFC module is reduced to a dimming operation of the LED lighting device 1 to reach. For example, the current can be reduced to a dimming supply current, which z. B. only 5% of the normal supply current of the LED total chain 9 is. As a result, the LEDs of the LED total chain 9 already heavily dimmed. A further reduction of the brightness is not possible by a reduction of the current flow, since the LED total chain 9 then it would start to flicker. However, the brightness can be controlled by the super dimming operation by activating the short circuit arrangement 8a , b be further reduced.

The 5a shows the LED overall chain 9 of the 1 in a first exemplary circuit implementation. The LED overall chain 9 includes an input E and an output A (or a first and a second pole), via which the LED overall chain 9 to the in the 1 shown power supply is connected.

The LED overall chain 9 includes four LED subgroups in this example 11a , b, c, d, where each LED subgroup 11a , b, c, d has at least one LED. In particular, each LED subgroup has 11a , b, c, d are the same forward voltage (also called forward voltage). The LEDs in the LED subgroups 11a , b, c, d can - as symbolically in the 5a shown - in each of the LED subgroups 11a , b, c, d be connected in series (or in series) to each other. In modified embodiments, the LEDs in the LED subgroups 11a , b, c, d are also connected in parallel, in series or in parallel and mixed in series with one another.

The four LED subgroups 11a However, b, c, d are in the in the 5a shown first circuit state I of the LED overall chain 9 arranged electrically parallel to each other, so that the forward voltage of the LED overall chain 9 the forward voltage corresponds to one of the LED subgroups.

In the 5b a second circuit state II is shown, wherein the LED subgroups 11a , b, c, d in the overall LED chain 9 now partly electrically connected in series (in series). For example, it is provided that in the first group, the LED subgroups 11a , B are arranged parallel to each other and in the second group, the LED subgroups 11c , D are also arranged parallel to each other, but the two groups are arranged serially to each other. In the circuit state II, the forward voltage corresponds to the total LED chain 9 now twice the forward voltage of one of the LED subgroups 11a , b, c, d.

In the 5c a third circuit state III is shown, where now all four LED subgroups 11a , b, c, d to each other are arranged electrically in series (in series). The forward voltage of the LED overall chain 9 now corresponds to four times the forward voltage of one of the LED subgroups 11a , b, c, d.

At each transition from one circuit state to a next circuit state, there is a transition from a lower circuit state to a higher circuit state in which at least one pair of LED subgroups previously connected in parallel 11a , b, c, d have been connected in series. Thus, in the transition from the circuit state I to II, the previously arranged parallel LED subgroups 11a and 11c as well as the previously parallel LED subgroups 11b . 11d connected in series with each other. During the transition from circuit state II to circuit state III, the LED subgroups connected in circuit state II become parallel to one another 11a , b or parallel to each other LED subgroups 11c , d in each case connected in series with each other.

The circuit device 10 is formed, the LED overall chain 9 to switch to the different circuit states I, II, III. A corresponding control circuit for this type of switching can be realized, for example, with the aid of diodes and transistors.

The bridging of the LED overall chain 9 takes place during the first circuit implementation via the external short-circuit arrangement 8a ,

The 6a , b, c, 7a , b show the LED overall chain 9 in the 1 in a second circuit configuration in a schematic representation. The LED overall chain 9 includes the input E and the output A (or a first and a second pole), via which the LED overall chain 9 to the in the 1 shown power supply is connected.

The LED overall chain 9 includes in this example three LED subgroups 11a , b, c, which analogous to the LED subgroups in the 5a , b, c, so that reference is made to the preceding description.

The three LED subgroups 11a , b, c are in the in 6a , b, c shown total chains 9 electrically serially arranged to each other. The series-connected LED subgroups 11a , b, c form in the overall LED chain 9 at the same time a LED string 18 , Each of the LED subgroups 11a , b, c is a short-circuit device 22a , b, c associated with the corresponding or associated LED subgroups 11a , b, c can bridge. This forms the short-circuit device 22a , b, c a switchable bypass for the associated LED subgroups 11a , b, c.

In the in the 6a shown first circuit state I is the short-circuiting devices 22a opened and the short-circuit facilities 22b , c closed. The forward voltage of the entire chain 9 between input E and output A thus corresponds to the forward voltage of the LED subgroup 11a ,

In the 6b is a second switching state II of the same overall chain 9 shown, wherein in the switching state II, the short-circuiting devices 22a and 22b are open and the short-circuit device 22c is closed, so that the forward voltage of the whole chain 9 between input E and output A of the sum of the forward voltages of the LED subgroups 11a , b corresponds.

In the 6c is a third switching state III of the whole chain 9 shown, wherein in this switching state III all three short-circuiting devices 22a , b, c are opened so that the forward voltage of the whole chain 9 the sum of the forward voltages of the LED subgroups 11a , b, c corresponds.

In the 7a is a variant of the switching state I in the 2a shown, wherein instead of the short-circuit device 22a the short-circuit device 22c is open and the other two short-circuit facilities 22a , b are closed. In the same way is in the 7b a variant of the switching state II of 6b shown, wherein instead of the short-circuit device 22c the short-circuit device 22a is closed and the other short-circuit facilities 22b , c are open.

At each transition from one circuit state to a next circuit state, the forward voltage of the entire chain also becomes 9 changed. If the forward voltage between input E and output A in the 6c as the maximum forward voltage of the whole chain 9 Thus, the forward voltage in the circuit state I in the 6a . 7a one third of the maximum forward voltage of the entire chain 9 , In the switching state II in the 6b and 7b the on-state voltage is two-thirds of the maximum forward voltage in the circuit state III.

The control device 10 is educated, the whole chain 9 in the different circuit states I, II, III and their variants to switch. A corresponding control circuit for this type of switching can be z. B. by means of diodes and transistors realize. It is also possible that the short-circuiting devices 22a , b, c via control signals from the controller designed as a microcontroller 10 to be controlled.

To the LEDs in the LED subgroups 11a The same time, to activate b, c on the average or to achieve an improved areal distribution of the illuminated LEDs are provided by the control device 10 the different variants of the circuit states I and II activated. Thus, for example, be provided that at a first half-wave in the 6a shown variant, in the second half wave in the 7a shown variant and in a third half-wave, another variant of the circuit state I is activated, in the further variant, the short-circuit device 22b is open. If the frequency of the AC power supply is sufficiently high, at this Distribution the three LED subgroups 11a , b, c perceived by a human observer as uniformly bright, since the rapid change is not traceable to the human eye.

Although in the 6a , b, c or 7a , b only three LED subgroups 11a , b, c, the number of LED subgroups can be arbitrarily selected, so it is possible that in the overall chain 9 only two LED subgroups are provided, but it may also be that in the overall chain 9 four, five or more LED subgroups are connected in series.

In the 8th is a schematic representation of a modification of the second circuit implementation shown, which several LED strands 18a , b, c, wherein further LED strands are possible, as indicated by the dots. Each of the LED strands 18a , b, c in this embodiment comprises three (or more) LED subgroups 11a , b, c with short-circuiting devices 22a , b, c and connected in series to a common switching device 15a , b, c, which is in each case designed as a controllable switch and an interruption of the LED string 18a , b or c allows. In this embodiment, it is possible, on the one hand via the activation or deactivation of the short-circuiting devices 22a , b, c in the different LED strings 18a , b, c is the total forward voltage between input E and output A of the whole chain 9 set in the manner described.

By switching on or off of LED strings 18a , b, c it is also possible, the distribution of the power absorbed and / or the absorbed chain flow through the control device 10 to change. In this embodiment, it is thus possible that the control device 10 the LED overall chain 9 controls so that this one has a forward voltage, which is adapted to the current chain tension and the second on the connection and disconnection of LED strands 18a , b, c can control the distribution of the absorbed current.

In the 8th is again the current sink device 7 shown, which is designed as a controllable or controllable current sink, which is driven in this embodiment with a synchronous to the mains voltage or the filtered mains voltage or supply voltage sinusoidal signal, so that the modules comprising the current sink device 7 and the LED overall chain 9 receives a sinusoidal chain current synchronous with the sine signal.

The short-circuiting devices 22a , b, c possibly form together with the group switching device 15a , b, c the internal short circuit arrangement 8b in the 1 ,

The 9a , b, c, d, 10a , b show the LED overall chain 9 in a third circuit implementation in a schematic representation. The LED overall chain 9 includes the input E and the output A (or a first and a second pole), via which the LED overall chain 9 to the in the 1 shown power supply is connected.

The LED overall chain 9 includes four LED subgroups in this example 11a , b, c, d, which analogous to the LED subgroups in the 5a , b, c, so that reference is made to the preceding description.

Each of the LED subgroups 11a , b, c, d is a series switching device 32a , b, c, d assigned. The series switching devices 32a , b, c, d are in series with the associated LED subgroup 11a , b, c, d arranged such that upon opening of the series switching device 32a , b, c, d a current flow through the associated LED subgroups 11a , b, c, d is interrupted. The LED subgroups 11a , b, c, d form with the associated series switching devices 32a , b, c, d each have an LED assembly 33a , b, c, d.

The LED assemblies 33a , b, c, d are in LED columns 34a b arranged and connected in series with each other, wherein in the LED row 34a the LED assemblies 33a , c and in the LED column 34b the LED assemblies 33b , d are arranged.

In addition, the LED modules 33a , b, c, d in LED lines 35a , b being arranged, being in the led row 35a the LED assemblies 33a , b and in the LED line 35b the LED assemblies 33c , d are arranged. In terms of the LED lines 35a , b are the LED assemblies 33a , b, c, d electrically connected in parallel.

Every LED line 35a , b is a short-circuit device 36a , b, which allows the associated LED rows 35a , short circuit, bypass, or make a bypass to it.

The series switching devices 32a , b, c, d and the short-circuiting devices 35a , b are by the controller 10 switchable. Thus, it is possible via the control device 10 the whole chain 9 in a different switching states, wherein a switching state by the forward voltage - also called forward voltage - between input E and output A - or between the two poles of the overall chain 9 - is defined.

In the 9a , b, c, d four different variants of a switching state I are shown. In the 9a the switching state is designed so that the forward voltage of the LED overall chain 9 by the forward voltage of the LED subgroup 11a is formed, since all other LED subgroups 11b , c, d either via the series switching device 32b for the LED subgroup 11b or by the short-circuiting device 35b for the LED subgroups 11c , d are disabled.

By changing the control is in the 9b exclusively the LED subgroup 11b , in the 9c exclusively the LED subgroup 11c and in the 9d exclusively the LED subgroup 11d illuminated. However, all variants of the switching state I have the same forward voltage, since the forward voltages of the LED modules 33a , b, c, d or the LED subgroups 11a , b, c, d are the same.

In the 10a , b is the same overall LED chain 9 shown in a circuit state II, wherein the forward voltage between the input E and the output A or the two poles of the sum of the forward voltages of the LED assemblies 33a , c for the variant in the 10a and the sum of the LED assemblies 33b , d for the variant in the 10b results. If one goes back to the same passage voltages in the LED modules 33a , b, c, d off, the forward voltage in the switching state II in the 10a , b twice as high as the forward voltage of the LED overall chain 9 in the 9a , b, c, d in the switching state I.

At each transition from a switching state I to a next switching state II or in the opposite direction, the forward voltage of the LED overall chain 9 changed. The control device 10 is educated, the whole chain 9 in the different circuit states I and II and their variants to switch. A corresponding control circuit for this type of switching can be z. B. by means of diodes and transistors realize. It is also possible that the short-circuiting devices 35a , b or the series switching devices 32a , b, c, d via control signals from the controller designed as a microcontroller 10 to be controlled.

To the LEDs in the LED subgroups 11a , b, c, d on average to activate the same or to achieve an improved areal distribution of the illuminated LEDs are from the control device 10 the different variants of the circuit states I and II activated. Thus, for example, be provided that at a first half-wave in the 9a shown variant, in the second half wave in the 9b shown variant, in a third half wave in the 9c shown variant and in a fourth half wave in the 9d shown half-wave is activated. In the same way, the two variants of the circuit state II can alternate. If the frequency of the AC power supply is sufficiently high, the four LED sub-groups will be used in this distribution 11a , b, c, d perceived by a human observer as uniformly bright, since the rapid change is not traceable to the human eye.

Although in the 9a , b, c, d or 10a , b only four LED subgroups 11a , b, c, d, the number of LED subgroups can be arbitrarily selected. So it is possible that in the overall chain 9 only two LED subgroups are provided, but it may also be that in the overall chain 9 four, five or more LED subgroups are present.

To clarify is the 11 is a schematic representation of another LED overall chain 9 shown which multiple LED columns 34a , b, x, wherein still further LED columns are possible, as indicated by the dots. Each of the LED columns 34a , b, x in this embodiment comprises two LED assemblies 33a , b, c, d, x, y, which in this example two LED rows 35a , b, in other embodiments, other LED lines can be added. Also in this embodiment, it is possible, on the one hand on the activation or deactivation of the short-circuiting devices 36a , b, c and the series switching devices 32a , b, c, d, x, y in the different LED columns 34a , b, x is the total forward voltage between input E and output A of the overall chain 9 set in the manner described.

By switching on or off of parallel LED modules 33a , b, c, d, x, y, it is also possible, the distribution of the power absorbed and / or the absorbed chain flow through the control device 10 to change. In this embodiment, it is thus possible that the control device 10 the LED overall chain 9 by controlling the short-circuiting devices 36a , b controls so that on the one hand this has a forward voltage, which is adapted to the current chain tension and the second on the connection and disconnection of LED modules 33a , b, c, d, x, y via the series switching devices 32a , b, c, d, x, y can control the distribution of the absorbed current.

The internal short circuit arrangement 8b gets through the short-circuiting devices 36a , b formed together.

LIST OF REFERENCE NUMBERS

1

LED lighting device

2

AC power supply

3

entrance

4

Line filter

5

rectifier

6

PFC module

7

Current sink means

8a, b

Short circuit arrangement

9

LED total chain

10

circuit means

11a, b, c, d

LED subgroups

13

half-wave

14

empty

15, 15a, b, c

Collective switching device

17

empty

18a, b, c

LED cluster

19-21

empty

22a, b, c, d

Short-circuit device

32a, b, c, d

Series switching device

33a, b, c, d

LED assembly

34a, b

LED columns

35a, b

LED lines

36a, b

Short-circuit device

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 202011105404 U1 [0004]

Claims (13)

LED lighting device ( 1 ) for an AC power supply ( 2 ), with several LEDs, which is an overall chain ( 9 ), the LEDs being divided into LED subgroups ( 11a, b, c, d ), wherein in the LED lighting device ( 1 ) is a supply voltage of varying amplitude, the supply voltage by repeating wave sections ( 13 ), characterized by a control device ( 10 ), wherein the control device ( 10 ), the overall chain ( 9 ) in at least two circuit states (I, II, III), the circuit states (I, II, III) being determined by the forward voltage of the overall chain ( 9 ), the control device ( 10 ), the overall chain ( 9 ) in response to the amplitude of the supply voltage, wherein the circuit states (I, II, III) in a normal operation of the LED lighting device ( 1 ) during one of the shaft sections ( 13 ) are changed at least twice, and by a short circuit arrangement ( 8a, b ) for bridging the LED subgroups ( 11a , b, c, d) of the total chain ( 9 ), wherein the control device ( 10 ), the short-circuit arrangement ( 8a, b ) in a super dimming operation, so that the LED subgroups ( 11a , b, c, d) of the total chain ( 9 ) for at least a sub-period (KX) of the wave segment ( 13 ) are disabled. LED lighting device ( 1 ) according to claim 1, characterized in that the at least one sub-period (KX) overlaps with a period of the wave segment in which the supply voltage is greater than the forward voltage of the overall chain (KX). 9 ). LED lighting device ( 1 ) according to claim 1 or 2, characterized in that the at least one sub-period (KX) with an initial section (K) and / or with an end section (K) of the shaft section ( 13 ) overlaps. LED lighting device ( 1 ) according to one of the preceding claims, characterized by a controllable current source ( 6 ), wherein the control device ( 10 ), the controllable current source ( 6 ) in a dimming operation, so that a supply current is reduced to a Dimmversorgungsstrom. LED lighting device ( 1 ) according to claim 4, characterized in that the dimming supply current is less than 20%, preferably less than 10% and in particular less than 5% of the supply current is formed in normal operation. LED lighting device ( 1 ) according to claim 4 or 5, characterized in that the control device ( 10 ) is designed to set the super dimming operation at the same time as the dimming operation. LED lighting device ( 1 ) according to one of the preceding claims, characterized by a current sink device ( 7 ), which are in series with the total chain ( 9 ) is connected and at which the supply voltage and a supply current is applied, wherein the current sink device ( 7 ) is formed, a chain flow for the entire chain ( 9 ), so that the time profile of the supply current with the time profile of the supply voltage or the time course of a mains voltage of the AC power supply ( 2 ) is synchronized, LED lighting device ( 1 ) according to one of the preceding claims, characterized in that the Superdimmmbetrieb is continuously adjustable. LED lighting device ( 1 ) according to one of the preceding claims, characterized in that the control device ( 10 ), the overall chain ( 9 ) in a lower circuit state (I, II), wherein at least two LED subgroups ( 11a , b, c, d) are connected in parallel with each other and wherein the total chain ( 9 ) in the lower circuit state (I, II) has a first forward voltage, and the whole chain in a higher circuit state (II, III) connect the at least two LED subgroups in series with each other, the overall chain ( 9 ) in the higher circuit state (II, III) has a second forward voltage which is greater than the first forward voltage. LED lighting device ( 1 ) according to one of claims 1 to 8, characterized in that a plurality of LED subgroups ( 11a , b, c) are arranged in series with each other and an LED strand ( 18 . 18a , b, c), wherein the LED lighting device ( 1 ) Short-circuit devices ( 22a , b, c), each for bridging one of the LED subgroups ( 11a , b, c) in the LED strand ( 18 . 18a , b, c) are formed, wherein the control device ( 10 ), the short-circuit devices ( 22a , b, c) to control the LED string ( 18 . 18a , b, c) into at least two circuit states (I, II), the short-circuit devices ( 22 . 22a , b, c) the short-circuit arrangement ( 8b ). LED lighting device ( 1 ) according to one of claims 1 to 8, characterized by a plurality of series switching devices ( 32a , b, c, d, x, y), where the LED subgroups ( 11a , b, c, d, x, y) each one of the series switching device ( 32a , b, c, d, x, y) associated with the LED subgroups ( 11a , b, c, d, x, y) with the associated series switching devices ( 32a , b, c, d, x, y) each have an LED assembly ( 33a , b, c, d, x, y), the series switching devices ( 32a , b, c, d, x, y) for interrupting a current flow in the respective LED subgroup ( 11a , b, c, d, x, y) are formed, and wherein a plurality of series-connected LED assemblies ( 33a , b, c, d, x, y) an LED column ( 34a , b) with LED lines ( 35a , b) by a plurality of short-circuiting devices ( 36a , b), wherein the LED rows ( 35a , b) one of the short-circuit devices ( 36a , b) and wherein the short-circuit device ( 36a , b) for bridging the LED assembly ( 33a , b, c, d, x, y) in the LED row ( 35a , b), wherein the control device ( 10 ), the short-circuit devices ( 36a , b) and the series switching devices ( 32a , b, c, d, x, y) to control the total chain ( 9 ) into the at least two circuit states (I, II), the short-circuit devices ( 36a , b) the short-circuit arrangement ( 8b ) form. LED lighting device ( 1 ) according to one of the preceding claims 10 or 11, characterized in that the control device ( 10 ), the overall chain ( 9 ) to control the overall chain ( 9 ) in several variants of a circuit state (I, II), wherein the variants the same forward voltage of the total chain ( 9 ), but a different selection of deactivated LED subgroups ( 11a , b, c, d, x, y). Method for operating the LED lighting device ( 1 ) according to one of the preceding claims, wherein the control device ( 10 ) the short-circuit arrangement ( 8a , b) in a super dimming operation controls so that the LED subgroups ( 11a , b, c, d) of the total chain ( 9 ) for at least a sub-period (KX) of the wave segment ( 13 ) are bridged.

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