EP3128811B1 - Device for supplying light sources with energy in a manner that increases their service life, by reducing current/voltage surges - Google Patents

Description

Introduction and state of the art

The invention relates to a circuit for supplying power to a sequential circuit of typically non-linear loads by means of a current source. Preferably, the load is a series circuit of LEDs. This current-driven load, preferably an LED series circuit, consisting of one to N elements and is to be partially short-circuited or dimmed.

Various power supply circuits for LEDs or LED series circuits are off US-A-2012/223649 . DE-A-10 2009 025 752 . US-A-2012/153844 and US-A-2010/194274 known.

For each of the non-linear loads connected in series, one switch is typically connected in parallel. These are each opened and / or closed.

The problem now arises that the current through the resulting voltage change is a combination of the current of the current source and the changing voltage of a typically existing energy storage and thus is no longer determined directly from the power source. Such a current source can be, for example, a current-controlled DC / DC converter.

1. a Der erste Fall, nämlich der Fall SCHLIESSEN, betrifft das Schließen oder die Durchlasswiderstandsverringerung eines oder mehrerer der besagten Schalter: Die daraus resultierende kurzfristige Stromüberhöhung kann unerwünschte Nebenwirkungen bis zur Beschädigung der nachfolgenden Last haben.
2. b Der zweite Fall, d. h. der Fall ÖFFNEN, betrifft das Öffnen oder die Durchlasswiderstandserhöhung eines oder mehrerer der besagten Schalter: Bis zur Ladung eines unterstützenden Energiespeichers auf einen erhöhten Energieinhalt - im Falle eines Kondensators auf eine erhöhte Spannung - steht möglicherweise kein oder ein nicht ausreichender Strom für die vergrößerte Last zur Verfügung. Dies kann die Funktion zeitweise einschränken. Beispielsweise kann es zu einer wahrnehmbaren Absenkung der Leuchtintensität einer LED-Kette kommen. Bei kurzen Transienten werden diese jedoch in der Regel durch LEDs als Lasten nicht wahrgenommen. Falls es sich allerdings um Motorphasen oder Relais handelt, könnte ein Abriss des Stromes, wie beschrieben, unerwünschte Nebeneffekte haben.

There are two cases:

1. a The first case, the case CLOSE, concerns the closing or the reduction of the ON resistance of one or more of said switches: the resulting short-term current overshoot can have undesirable side effects until the subsequent load is damaged.
2. b The second case, ie the OPEN case, concerns the opening or the On-resistance increase of one or more of said switches: Until charging a supporting energy storage to an increased energy content - in the case of a capacitor to an increased voltage - there may be no or insufficient current available for the increased load. This can temporarily restrict the function. For example, there may be a noticeable reduction in the luminous intensity of an LED chain. For short transients, however, these are usually not perceived by LEDs as loads. However, if they are motor phases or relays, current demolition, as described, could have undesirable side effects.

Object of the invention

It is the object of the invention to deliver a constant, optionally maximum energy at all times without limit values being exceeded, in particular by transients, and without significant changes in the energy conversions taking place in the actuators.

At the same time, the device should be able to detect faulty consumers.

This object is achieved with a device according to claim 1. Individual embodiments of the invention are the subject of the dependent claims. 1

• mindestens ein Zustandswert der Vorrichtung über eine Schnittstelle übertragen werden, wobei dieser Zustandswert einer der folgenden Zustandswerte oder deren zeitliche einfache oder höhere Ableitung sein kann:
  1. a) ein Regelwert eines der Ausgänge des Reglers
  2. b) ein interner Regelwert des Reglers
  3. c) ein Messwert oder Zustandswert eines der Sensoren
  4. d) der Stromwert einer der Strommessstellen
  5. e) der Spannungswert an einem der Knoten
  6. f) die Differenz zwischen Regelwert und Messwert am Regler
  7. g) der Zustand eines oder mehrerer der beteiligten Schaltelemente
  8. h) ein Messwert entsprechend der Spannung über mindestens einem der Schaltelemente
  9. i) ein Messwert entsprechend dem Strom in mindestens einem der Schaltelemente

This may be useful if

• At least one state value of the device can be transmitted via an interface, wherein this state value can be one of the following state values or their temporally simple or higher derivative:
  1. a) a control value of one of the outputs of the regulator
  2. b) an internal control value of the controller
  3. c) a measured value or state value of one of the sensors
  4. d) the current value of one of the current measuring points
  5. e) the voltage value at one of the nodes
  6. f) the difference between the control value and the measured value at the controller
  7. g) the state of one or more of the involved switching elements
  8. h) a measured value corresponding to the voltage across at least one of the switching elements
  9. i) a measured value corresponding to the current in at least one of the switching elements

1. a) Messung des Stroms durch die LED-Kette und Messung des Energieinhalts des Kondensators (Energiespeicher) sowie deren zeitlichen Ableitungen zur Steuerung der Leistungstransistoren
2. b) Messung der zeitlichen Ableitungen des Stroms durch die LED-Kette oder Messung des Energieinhalts sowie dessen zeitlichen Ableitungen des Kondensators (Energiespeicher)zur Steuerung der Leistungstransistoren
3. c) Messung des Stroms durch die LED-Kette und/oder Messung des Energieinhalts des Kondensators (Energiespeicher) sowie deren zeitlichen Ableitungen zur Steuerung der Leistungstransistoren und Änderung des Duty-Cycles, wenn ein Maximalwert für den Strom durch die LED-Kette oder für dessen zeitliche Ableitungen überschritten wird oder wenn ein Minimalwert analog unterschritten wird.
4. d) Messung des Stroms durch die LED-Kette und/oder Messung des Energieinhalts des Kondensators (Energiespeicher) sowie deren zeitlichen Ableitungen zur Steuerung der Leistungstransistoren und Änderung des Duty-Cycles, wenn ein Maximalwert für den Energieinhalt des Energiespeichers (Kondensator) oder für dessen zeitliche Ableitungen überschritten wird oder wenn ein Minimalwert analog unterschritten wird.
5. e) Messung des Stroms durch die LED-Kette und/oder Messung des Energieinhalts des Kondensators (Energiespeicher) sowie deren zeitlichen Ableitungen zur Steuerung der Leistungstransistoren und gleichzeitig wird kein Schalter geschlossen, wenn der Strom oder eine seiner Ableitungen über einem Maximalwert liegt und/oder kein Schalter geöffnet, der Strom oder eine seiner Ableitungen unter einen Minimalwert liegt
6. f) Messung des Stroms durch die LED-Kette und/oder Messung des Energieinhalts des Kondensators (Energiespeicher) sowie deren zeitlichen Ableitungen zur Steuerung der Leistungstransistoren und es wird kein Schalter gleichzeitig mit einem anderen geschlossen oder geöffnet.
7. g) Messung des Energieinhalts des Kondensators (Energiespeicher) sowie deren zeitlichen Ableitungen zur Steuerung der Leistungstransistoren

The term "current source" in the context of this invention generally means a source for the supply of electrical energy. In this regard, in addition to a power source in the narrower sense alternatively offers a switching regulator. It is crucial that electrical energy can be introduced into the output node by the provision of electrical current and / or electrical voltage. As an aspect of the measurement, one or more of the following aspects can be cited.

1. a) Measurement of the current through the LED chain and measurement of the energy content of the capacitor (energy storage) and their time derivatives for controlling the power transistors
2. b) Measurement of the time derivatives of the current through the LED chain or measurement of the energy content and its time derivatives of the capacitor (energy storage) for controlling the power transistors
3. c) Measurement of the current through the LED chain and / or measurement of the energy content of the capacitor (energy storage) and their time derivatives for controlling the power transistors and change the duty cycle, if a maximum value for the current through the LED chain or for its time derivative is exceeded or if a minimum value is fallen below analog.
4. d) Measurement of the current through the LED chain and / or measurement of the energy content of the capacitor (energy storage) and their time derivatives for controlling the power transistors and change the duty cycle, if a maximum value for the energy content of the energy storage (capacitor) or for its time derivative is exceeded or if a minimum value is fallen below analog.
5. e) Measurement of the current through the LED chain and / or measurement of the energy content of the capacitor (energy storage) and their time derivatives for controlling the power transistors and at the same time no switch is closed when the current or one of its derivatives is above a maximum value and / or no switch is open, the current or one of its derivatives is below a minimum value
6. f) measurement of the current through the LED chain and / or measurement of the energy content of the capacitor (energy storage) and their time derivatives for controlling the power transistors and no switch is closed or opened simultaneously with another.
7. g) Measurement of the energy content of the capacitor (energy storage) and their time derivatives for controlling the power transistors

Description of the basic invention

Figur 1

ein Blockschaltbild der erfindungsgemäßen Vorrichtung,

Figur 2

einen beispielhaften sehr einfachen Regler für einen Schalter,

Figur 3

eine Ausführung der erfindungsgemäßen Vorrichtung mit zwei parallelen Strängen,

Figur 4

eine Ausführung zur Ansteuerung einer farblich steuerbaren RGB Beleuchtung.

In the following the invention will be described with the aid of the exemplary figures. Show here

FIG. 1

a block diagram of the device according to the invention,

FIG. 2

an exemplary very simple regulator for a switch,

FIG. 3

an embodiment of the device according to the invention with two parallel strands,

FIG. 4

a version for controlling a color-controllable RGB lighting.

The object is achieved by an evaluation of the current in the loads 4 during the switching transition to the switching elements 3 by a current-measuring element 5 or by a regulator 6.

The task of the controller 6 is to evaluate either the voltage or the voltage change rate dU / dt at the energy storage 2 or the current change at the measuring element 5 or at both components in order to predetermine the operation within a predefined operating state space, to check and thus to ensure.

The described critical faults in OPENING and CLOSING see above can thus be prevented. Thus, an uncontrolled increase or reduction of the current during the transient transitions in the system can be prevented or at least controlled in its effect controlled. In particular, in the case of LEDs as consumers, the life of the diodes can thereby be significantly increased by attenuating peak currents through the device described and controlled controlled.

Another advantage of the device described is the possibility of adaptive control, which under given boundary conditions such as. the aging of components z. B. the age-related change in capacity 2, the shortest possible transient reversal of the switching elements 3 allows.

The power source 1 in FIG. 1 supplies the current and the energy for the series-connected consumers 4, 10. In this case, these are, for example, a first light-emitting diode 4 and a second light-emitting diode 10. In the following, light-emitting diodes are referred to as LEDs.

The energy storage device 2 in this case is a capacitor 2, which buffers the voltage at the output node 7 of the current source 1. This happens in this exemplary case via an optional series resistor 14 between the output node 7 of the current source 1 and the terminal node 8 of the capacitor 2, which acts as an energy storage 2. The other pole of the capacitor 2 is connected to ground in this example. This exemplary arrangement advantageously enables the evaluation of the amount of energy or the change in the amount of energy on the memory 2.

As already described, the first LED 4 and the second LED 10 are respectively associated with a corresponding first switch 3 and a second switch 9, which bridge the LEDs 4, 10 by CLOSE or OPEN and so the energy distribution within the LED chain from these LEDs 4, 10 can change. To achieve the object according to the invention, therefore, not the energy source, that is, the current source 1, is regulated, but the entirety of the consumers 4, 10, which represents the essential inventive step for solving the problem.

In order to make the OPENING and CLOSING of the switches 3, 9 such that the tolerances for the current through the load chain, that is to say through the LED chain consisting of the LEDs 4, 10, are not exceeded, it is possible, for example, via a shunt resistor 5 the current through said load chain is measured by detecting the voltage drop between the current sense node 11 and ground. Instead of a shunt resistor 5, of course, other current measuring methods such as a Hall or AMR sensor are conceivable. Also, for example, the resistor 14 can be used at the energy storage 2 for the evaluation, since the current in the energy storage 2 into or out of this with the current through the load chain 4, 10 and the switches 3, 9 in total must give the current source current.

The thus detected signal 11 is supplied to the controller 6, which typically also the energy content of the energy storage device 2, for example by a potential measurement of the node 8 of a capacitor 2, monitored. In addition, it makes sense to also monitor the voltage of the feed node 7, whereby by means of the aforementioned second shunt resistor 14, a measurement of the current into and out of the energy storage is possible.

In this way it can be concluded that the energy content of the capacitor or the energy storage device 2. Also, the time derivatives of the quantities can be used to determine the rates of change of the energy content.

So if we are talking about measurement of the energy content, then only one method is meant, with which the energy content can at least be sufficiently concluded for the application. Of course, further measuring points are conceivable.

FIG. 2 shows a realization of a system in which only one consumer 10 in a chain of two Nutzverbrauchern 4, 10 is regulated.

The particularly simple technical realization of a very simple variant of the controller 6, which does not have all possible features of this regulator, but may already belong to a device according to the invention, in this case, a transimpedance amplifier 15, the controlling currents to a switching element 9 using the Miller effect adjusts to control. Of course, the invention also includes much more complicated variants of the regulator 6, which will become apparent to those skilled in the art from the spirit of the invention. The following describes some of the possible extensions of such a controller. The controller 6 now compares the voltage drop across the exemplary shunt resistor 5 at the node 11 with an exemplary reference voltage V _ref , which acts as a predefinable setpoint reference.

By means of appropriate filters, the controller can be designed, for example, as a P, PI, PID or PD controller. More complex control transfer functions of controller 6 with multi-dimensional, d. H. Multi-parameter input and output signals are naturally conceivable and, in particular in the case of more complicated topologies, as described below, makes sense.

The device according to the invention thus serves to supply a circuit with at least one consumer. It has at least one power source 1. The energy supply is via at least one energy storage 2 in the form of z. B. a capacitor, batteries, etc. stabilized. In this energy storage 2, it may also be a coil, which is for example inserted serially into the circuit. Both current source 1 and energy storage 2 feed energy into a first output node 7. About said output node 7, said consumers 4 are at least temporarily supplied with energy. It is also conceivable that the system is not always active. The energy storage 2 always supplies energy when the energy supply of the power source 1 for the supply of the consumer 4, 10 is not sufficient and the energy storage 2 still has sufficient energy content. This sufficient energy content is permanently measured and predicted by the controller 6 and suitable measuring points 8, 7 in the system. If the energy removal by the loads 4, 10 from the combined energy source from the current source 1 and the energy store 2 is too high or too low, then the total load 4, 10 is changed as a manipulated variable for the correction of this situation. This is another essential inventive idea. Therefore, in the case of two consumers to at least one of said two consumers 4 at least one switch 9 must be connected in parallel. The latter can thus bridge at least one of the consumers 10 in order to lower the internal resistance of the total load of the consumers 4, 10 as required or to eliminate such bridging, to increase the internal resistance of the total load of the consumers 4, 10. For the purpose of this regulation sensors for measuring the state of the total load 5, the energy storage 14 and the energy conversion in the total load are useful. Therefore, the device according to the invention has a measuring device 5, which is capable of the current value for detecting the total load 4, 10 flowing through electric current and thus usually the rate of change of current or a higher time derivative of the current through the sequential interconnection of said Consumers 4, 10 to measure. The measurement of the derivatives allows a prognosis of the current development and thus a timely counter-regulation of the load 4, 10. It also makes sense to capture the remaining energy content of the energy storage device 2 by means of at least one further measuring device 14. Again, it makes sense again to detect the rate of change of this energy content of the energy storage device 2 or a higher time derivative of this energy content of the said energy storage device 2 and perform a predictive control. The energy conversion in the total load of the consumers 4, 10 can be calculated from the voltage drop between the nodes 7 and 11 and that between the node 11 and ground. The control by the controller 6 is effected in such a way that, as already described, it opens or closes at least one of the switches 3, 9 depending on at least one of the previously determined values or changes its forward resistance so that the tolerance values of the current do not be exceeded or fallen below.

It should be noted that although a complete CLOSE or OPEN power transistors is useful, but this can just lead to the said current peaks. It is therefore particularly favorable, with the described transimpedance amplifier 15, to control or close the power transistors 3, 9 so slowly that no or defined, predetermined current peaks are produced. As a result, the life of the LEDs 4, 10 is significantly extended. Thus, when we are talking about OPEN or CLOSE it means a controlled OPENING and CLOSING that does not exceed or fall short of the given tolerances of the current.

In the context of the invention, it has been recognized that it makes sense if no further switch 3, 9 is closed or increased in its forward resistance if the measured current through the totality of the consumers 4, 10 is above a predetermined value I _max1 , since this aggravating the situation. The same applies if the magnitude of the measured current increase rate is above a predetermined value I _{max_sp1} or if the magnitude of the measured higher time derivative of the current is above a predetermined value I _{max_ac1} .

Likewise, it does not make sense for one of the switches 3, 9 to be opened or increased in its forward resistance if the measured current through the entirety of the consumers 4, 10 is below a predetermined value I _min1 . Again, the analog applies to the case when the magnitude of the measured current _{slew rate} is below a predetermined value I _{min_sp1} or when the magnitude of the measured higher time derivative of the current is below a predetermined value I _{min_ac1} .

Of course, assuming general current driven loads, it is conceivable to perform a PWM modulation instead of the analog adjustment of the druchlass resistors of the switches 3, 9. In this case, for example, the average duration of the closure or Durchflußwiderstandsverringerung one of the switches 3, 9 is reduced at least temporarily with respect to a time period when the measured current through the totality of consumers 4.10 above a predetermined value I _max2 . Similarly, the average duration of the closure or _{ON resistance reduction of} one of the switches 3, 9 is reduced relative to a time period when the magnitude of the measured current _{slew rate} is above a predetermined value I _{max_sp2} or if the magnitude of the measured higher time derivative of the current is above a predetermined value I _{max_ac2} lies. Conversely, the average duration of the closure or _{ON resistance reduction of} one of the switches 3, 9 is increased at least temporarily when the measured current is below a predetermined value I _min2 , the magnitude of the measured current _{slew rate} is below a predetermined value I _{min_sp2} , or the magnitude the measured higher time derivative of the current is below a predetermined value I _{min_ac2} .

Likewise, the average duration of the closure or Durchflußwiderstandsverringerung one of the switches 3, 9 is reduced at least temporarily with respect to a time period when the measured energy _{content of} the energy storage _device 2 below a predetermined value W _{es_min2} or the amount of the measured energy _{content change} rate of the energy storage _device 2 above a predetermined value W _{es_max_sp2} is or the amount of the measured higher time derivative of the energy _{content of} the energy storage is above a predetermined value W _{es_max_ac2} . Since the voltage at node 8 is a good measure of the energy _content , these capacitor voltages for the case of a capacitor can instead be taken as energy storage 2 in relation to corresponding voltage _limits U _{es_min 2} , U _{es_max_sp 2} , U _{es_max_ac 2} as a measure for the decision to initiate these measures , So if in the claims of the energy content and the comparison of the energy content and / or its temporal derivations with a value is mentioned, then this means not only an energy content and its derivatives, but also all physical Quantities that allow an equivalent statement and their corresponding analog limits. Conversely, in an analogous manner, the average duration of the closure or Durchflußwiderstandsverringerung one of the switches 3, 9 is increased at least temporarily relative to a time period when the measured energy _{content of} the energy storage _device 2 is above a predetermined value U _{es_min3} or the amount of measured energy _{content change rate} below a predetermined value U _{es_max_sp3} or the average duration of the closure or Durchflußwiderstandsverringerung one of the switches 3, 9 is increased at least temporarily relative to a time period when the amount of the measured higher time derivative of the energy _{content of} the energy storage _device 2 is below a predetermined value U _{es_min_ac3} .

As already described, the switches 3, 9, which are typically power transistors, are driven by a regulating element 6, a regulator 6. This is done so that the current flowing through the entirety of the loads 4, 10 is detected during a switching operation by the measuring element 5 and is used as a controlled variable of this regulating element 6. The control is done by a power transistor 3, 9, which then limits the current, for example, to a value less than 1.1 or 1.2 or 1.4 times or twice the value flowing without switching by the consumer. This means that the overshoot of the current is thereby limited to 10% or 20% or 40% or 100%.

Conversely, an undershoot is limited, for example, to 10%, 20%, 50% or 70% of this value by the power transistor 3, 9 is suitably controlled by the regulating element 6 again. Here, too, the current through the totality of the consumers 4, 10 is also detected during a switching operation by the measuring element 5 and used as a controlled variable of the regulating element 6. In this case, limit the power transistors 3, 9, the current to a value greater than the 0.9 or 0.8 or 0.5 or 0.3 times in turn the value that flows without switching operation by the consumer 4, 10.

The following is the example FIG. 3 described.

It is also conceivable that a plurality of serial consumer strings, for example, from a first consumer string of two serially connected consumers 4, 10 and a second consumer string from two other serially connected consumers 17, 19 are supplied in parallel from a power source 1. This arrangement can be advantageously used for load distribution between the two consumer strands.

In this case, it may be expedient, for example, for a current measuring point 22 to be provided for the total current in both load strands, and for each load line to have a respective current measuring device 5, 21.

The switches 3, 9, 16, 18 are controlled by the controller 6 via the control lines 12, 13, 23, 24. In this example, shunt resistors 14, 22, 5, 21 are used as exemplary current measuring points. The corresponding potentials of the associated nodes 7, 8, 20, 11, 25 are supplied as exemplary input signals to the controller 6, which generates therefrom the control signals 12, 13, 23, 24 for the switches 3, 9, 16, 18.

In this case and in the case where all consumers 4, 10, 17, 19 are to be supplied with energy at least temporarily within one period, it makes sense to carry out the bridging of the consumers 4, 10, 17, 19 alternately. For example, it may be necessary to connect a plurality of the consumers 4, 10, 17, 19, for example LEDs, at least temporarily. In this case it may be necessary for the time of the energy supply to be within a period of time is divided proportionally, with multiple consumers, activity intervals may overlap, but not need. It may also occur times in which no consumer consumes 4, 10, 17, 19 energy and possibly the energy storage 2, if necessary, is charged with energy or can be loaded. For a capacitor 2, these are charging and discharging operations. If this case occurs, all consumers must be able to be disconnected. Such a switch, which would be serial to all consumers, is not shown in the figures.

In such a switching operation from one load to the other, it makes sense that by simultaneously CLOSING or simultaneously reducing the on resistance of a first switch, for example the switch 3, and simultaneously OPENING or simultaneously increasing the on resistance of a second switch, for example the switch 16, the current in the measuring element 22 or the rate of change of current in the measuring element 22 or a higher time derivative of the rate of change of current in the measuring element 22 remains within the predetermined or programmed range.

In the case of the parallel connection of several serial consumer branches, the measuring element 22 may also consist of several such elements 5, 21 in the individual branches with subsequent summation or a vectorial range specification or in a measuring element 22 in star points.

It is therefore possible that these conditions apply to the total current of a partial serial branch and / or to the total current of several partial serial branches and / or to the total current of all consumers supplied by the current source. It is also conceivable to specify both conditions for a plurality of sub-branches and / or the total current.

In the case of at least two loads to be supplied in parallel A source 1 can be advantageously brought about by modulation of the switching elements 3 by the controller 6, a predetermined current distribution in these loads. This modulation of the switching elements 3 by the controller 6 can be done for example by means of analog impedance variations or discrete-time by PWM control. This is of particular interest because otherwise the current distribution on the at least two branches can change uncontrollably.

Similarly, the number of switching operations in the consumer network that may overlap can be limited. It thus makes sense that during switching on and / or off, ie the OPENING or CLOSING, or the change of the forward resistance of a first switch, for example the switch 4, no second switch or only a predetermined number of second switch is turned on or off or is changed in his / her on-resistance. An advantageous design of this overlap represents the simultaneous OPENING and CLOSING of two N switches N 3 in such a way that the predetermined nominal value remains constant during the transitions.

In addition, it makes sense if it is ensured that the distance of such events takes place in such a way that the emitted electromagnetic radiation spectrum of the device meets the respective requirements of the application. For example, it is conceivable to specify a minimum time interval, here denoted by t _min _ _s , between two switching operations.

Typically, therefore, a device according to the invention can also have a plurality of branches of serial connections of consumers connected in parallel, these in turn each individually representing a device according to the invention. Of course, a branch may be a device not according to the invention if its influence is influenced by the control capabilities of the invention Branch can be compensated. In the simplest case, it may therefore be a single consumer, which is connected in parallel to a series circuit of two consumers or even only a single consumer and possibly also has a switch. In such a consumer network, there may be other energy stores and power sources at various points, which possibly stabilize and limit the power in individual branches.

In such a network, in order for the regulation to be effective, at least one consumer must have a switch connected in parallel. Of course, it may also be useful to monitor each of the branches individually or multiple branches in total by separate measuring devices. Here, too, the current value itself or the rate of change of current or a higher time derivative of the current can be measured by the respectively affected sequential sub-tree of said consumers and used for the regulation.

Finally, it should be mentioned that the opening and closing operation of a switch, for example of the switch 3, can be interrupted by the controller 6, if the system response in the form of the temporal current change of one of the currents at one or more of the measuring points 14, 22, 5, 21 does not occur within a tolerance band around a temporal change setpoint function. In the example, there are four currents at the measuring points 14, 5, 22, 21, ie a current vector. Accordingly, the tolerance band may also be a tolerance band with a multidimensional cross section. In this case, for example, a four-dimensional cross-section.

This opens the possibility to conclude on a mistake. This is particularly advantageous in the detection of safety-related failures, for example in rear lights of motor vehicles. Should So now, for example, break the current at an OPENING of the switch 3, an error in the corresponding load 4, such as an LED could be present such that the circuit is interrupted in this load 4 due to a fault of this load 4.

Conversely, a short circuit of the load 4 can be detected if the current does not rise when the switch 3 is CLOSED but, for example, remains the same.

By the device according to the invention can therefore be concluded that the state of the consumer chain, in this example consisting of the consumers 4, 10, 17, 19, and in particular their correct function.

The controller 6 can then depending on the specification on the one hand to change the controller function or even cancel the opening and closing process completely and / or other switches OPEN or CLOSE or otherwise change their state or change the topology of the device.

This monitoring has relevance in buck-switching regulators, which would put in the case of low input voltage maximum just this to the output. This is often the case in vehicles, for example. Thus, motor vehicles typically have a voltage dip during cranking or start / stop operation.

After all FIG. 4 should be mentioned that in a series connection of multiple consumers 4, 10, 17, the energy consumption of the individual consumers 4, 10, 17 can be controlled in total and relative to each other. As an example, the control of an RGB light-emitting diode unit for the color irradiation of an object O will be described here.

For example, it is conceivable in three consumers 4, 10, 17 in series, each with a switch 3, 9, 16, the OPENING and CLOSING of the switches 3, 9, 16 of three parameters, in the sequence as Y, M, K. described, to make dependent.

In this case, for example, a PWM modulation of the activity of the consumers 4, 10, 17 is used. If the three consumers 4, 10, 17 are, for example, three LEDs in the three primary colors red, yellow, blue, then the Y signal causes the brightness of all three diodes, with M and K the color vector, ie the relative brightness the three diodes regulated to each other. Since the perception by humans is strongly non-linear, it makes sense if, if necessary, a correction of the color vector by a correction function of the controller 6 takes place as a function of the Y signal and further brightness-determining parameters.

A brightness-determining parameter in this sense would be, for example, the energy supply of the power source and the energy content of the energy storage 2 and their derivatives.

• der LMS-Farbraum - der physiologische Farbraum, der auf den spektralen Empfindlichkeiten der L-, M-, S-Zapfen aufbaut,
• der XYZ-Farbraum - von der CIE ursprünglich aufgestellter Normfarbraum, auf rechnerischen Koordinaten X, Y, Z konstruiert, die aus Zapfenempfindlichkeiten erstellt sind,
• der RGB-Farbraum - der für Computermonitore und als Internetstandard genutzt wird,
• das CMYK-Farbmodell - das beim Desktoppublishing und in der Druck-Endstufe genutzt wird,
• der HSV-Farbraum mit den Varianten HSL, HSB, HSI - Design die typischerweise für Dokumentation von Malerei und in der Videokunst benutzt werden,
• der Lab-Farbraum - ein CIE-Farbenraum, der aus XYZ abgeleitet ist und der ebenfalls alle wahrnehmbaren Farben umfasst; und dessen Weiterentwicklung der DIN99-Farbraum darstellt,
• der LCh°-Farbraum, welcher keinen weiteren Farbraum im eigentlichen Sinne, bezeichnet, sondern eine Darstellung von HSV, LUV oder LAB in Polarkoordinaten ist,
• der I1I2I3-Farbraum, welcher ein rechentechnisch optimierter Farbraum für die Bildverarbeitung ist,
• das YCbCr-Farbmodell - kurz YCC -, das im digitalen Fernsehen insbesondere im digitales PAL, als auch im digitalen NTSC, DVB, JPEG, MPEG, DVD-Video Verwendung findet,
• den xvYCC Farbraum, einem gegenüber YCbCr erweiterten Farbraum, der die gesamten 8 Bit pro Farbkanal nutzt und für Flachbildschirme verwendet wird,
• das YPbPr-Farbmodell, das für analoges HDTV und analoge Component-Video-Signale verwendet wurde,
• das YUV-Farbmodell, das beim für analogen PAL und NTSC verwendet wurde,
• das YIQ-Farbmodell bei älteren Formen des analogen NTSC Verwendung fand,
• das YDbDr-Farbmodell das bei analogem SECAM Verwendung fand und
• das YCC-Farbmodell das für spezielle Photo CDs verwendet wird.

Of course, the application of any other color space models as a YMK color space is conceivable. Examples would be

• the LMS color space - the physiological color space based on the spectral sensitivities of the L, M, S cones,
• the XYZ color space - constructed by the CIE standard color space, constructed on computational coordinates X, Y, Z, which are created from pin sensitivities,
• the RGB color space - which is used for computer monitors and as an Internet standard,
• the CMYK color model - used in desktop publishing and in the final pressure stage,
• the HSV color space with the variants HSL, HSB, HSI - design which are typically used for documentation of painting and in video art,
• the Lab color space - a CIE color space derived from XYZ that also includes all perceptible colors; and whose further development is the DIN99 color space,
• the LCh ° color space, which denotes no further color space in the actual sense, but is a representation of HSV, LUV or LAB in polar coordinates,
• the I1I2I3 color space, which is a computationally optimized color space for image processing,
• the YCbCr color model - YCC for short - which is used in digital television, in particular in digital PAL, as well as in digital NTSC, DVB, JPEG, MPEG, DVD-Video,
• the xvYCC color space, a YCbCr extended color space that uses the full 8 bits per color channel and is used for flat panel displays,
• the YPbPr color model used for analog HDTV and analog component video signals
• the YUV color model used in analog PAL and NTSC
• the YIQ color model was used in older forms of analogue NTSC,
• the YDbDr color model used in analogue SECAM and
• the YCC color model used for special Photo CDs.

These exemplary formats are obviously just a selection of the possible color formats.

1. 1. die Abstrahlung der Leuchtdioden und/oder
2. 2. die Rückstrahlung vom zu beleuchtenden Objekt

misst und diese Werte in den Regler 6 einfließen.It makes sense if a color sensor 26 either

1. 1. the radiation of the LEDs and / or
2. 2. the reflection from the object to be illuminated

measures and these values are incorporated into the controller 6.

This is an example of the general case that the effect of the consumer 4, 10, 17 is monitored and also controlled by the controller 6.

1. 1. die Helligkeit der Beleuchtung und damit der Energieverbrauch der Lasten 4, 10, 17 der durch die Stromquelle 1 und dem Energiespeicher 2 zur Verfügung gestellten Energiemenge entspricht und
2. 2. die Energiemengenaufteilung auf die Verbraucher 4, 10, 17 dem Ziel - hier einer vorgegebenen farblichen Beleuchtung oder farblichen Rückstrahlung durch ein bestrahltes Objekt O - entspricht.

The controller 6 now ensures that

1. 1. the brightness of the lighting and thus the energy consumption of the loads 4, 10, 17 of the power source 1 and the energy storage 2 made available amount of energy corresponds, and
2. 2. the energy quantity distribution to the consumers 4, 10, 17 corresponds to the target - here a predetermined color illumination or color reflection by an irradiated object O -.

FIG. 4 shows only the regulation of the color reflection from the object O, moreover.

It is particularly advantageous that faulty states of the consumers 4, 10, 17, as described above can be detected.

Therefore, it makes sense if the controller can exchange state data via an interface IF with a control device, for example a data processing system.

These status data may be, for example, error states, switching states of the switching signals 13, 12, 23 and thus control values, values of the sensors 26 and the current measuring points 14, 5 and voltages at the nodes 7, 11.

Another control parameter may be the temperature of the system or parts of the system, in particular the temperature of the consumer 4, 10, 17 or the switch 13, 12, 23 or the power source 1. A corresponding sensor is however in FIG. 4 not shown, but is also evaluated by the controller 6.

A typical control algorithm of the controller 6 is then selected so that always the energy extraction from the two energy sources, the current source 1 and the energy storage 2 corresponds to a maximum value or an internally or externally predetermined value or the current value of a predetermined external control function of the time, if not the energy extraction is limited by other factors, for example, in this example, the brightness default or the temperature of system components. For example, it is conceivable that a constant value is set or that at certain night times in the case of LEDs different brightnesses are set as loads.

• den Stromwert und/oder
• die Stromänderungsgeschwindigkeit und/oder
• eine höhere zeitliche Ableitung des Stromwertes

zumindest durch einen ersten Verbraucher oder eine sequentielle Verschaltung von mehreren ersten Verbrauchern 4 oder ein Teilnetz von ersten Verbrauchern 4 zu messen. Weiter weist die Vorrichtung einen Regler 6 auf, der in Abhängigkeit von einem der zuvor ermittelten Werte einen der Schalter 3 öffnet oder schließt oder dessen Durchlasswiderstand verändert. Natürlich sind Vorrichtungen mit mehreren Schaltern und Verbrauchern denkbar, wie zuvor beschrieben. Der besagte Regler 6 überprüft dabei typischerweise gleichzeitig, ob die zeitliche Veränderung

• des Stromwerts und/oder
• der Stromänderungsgeschwindigkeit und/oder
• einer höheren zeitlichen Ableitung des Stromwertes durch den besagten - Verbraucher oder eine sequentielle Verschaltung von mehreren ersten Verbrauchern 4 oder dem zuvor genannten Teilnetz vorgabegerecht erfolgt. Die Überprüfung gegenüber einer Vorgabe erfolgt dabei in der Weise, dass der zu überprüfende Wert einer vorgegebenen Soll-Funktion in Abhängigkeit von dem zeitlichen Verlauf des ÖFFNENs oder SCHLIESSENs oder der Änderung des Durchlasswiderstands innerhalb eines vorgegebenen Toleranzbandes folgen muss.

Thus, there is provided a method of testing such a device in which one or more loads are operated in a device as previously described and defined in the claims. The device in this case has a measuring device 5 which is able to

• the current value and / or
• the rate of change of current and / or
• a higher time derivative of the current value

at least by a first consumer or a sequential interconnection of a plurality of first consumers 4 or a subnetwork of first consumers 4 to measure. Furthermore, the device has a regulator 6 which, depending on one of the previously determined values, opens or closes one of the switches 3 or changes its forward resistance. Of course, devices with multiple switches and loads are conceivable, as previously described. The said controller 6 typically checks at the same time whether the time change

• the current value and / or
• the rate of change of current and / or
• a higher temporal derivative of the current value by said - consumer or a sequential interconnection of several first consumers 4 or the aforementioned subnet is carried out according to specifications. The check with respect to a specification is carried out in such a way that the value to be checked must follow a predetermined desired function as a function of the time course of the OPENING or CLOSING or the change of the ON resistance within a predetermined tolerance band.

From this, the controller 6 or another component, for example a μ-controller, which receives data from the controller 6 via an interface IF, determines a measured value for the state of the consumer. The control function of the controller 6 is changed depending on the deviation from such a desired function. The measured value determined in this way can also be a binary measured value. For example, it is conceivable that the measured value means "defective" or "not defective".

• den verbleibenden Energieinhalt des Energiespeichers 2 und/oder
• die Änderungsgeschwindigkeit des Energieinhalts mindestens des Energiespeichers 2 und/oder
• eine höhere zeitliche Ableitung des Energieinhalts mindestens des besagten Energiespeichers 2

zu messen. Dabei weist die Vorrichtung typischerweise einen Regler 6 auf, der in Abhängigkeit von zumindest einem der zuvor ermittelten Werte typischerweise einen der Schalter 3 öffnet oder schließt oder dessen Durchlasswiderstand verändert. Dabei prüft der besagte Regler 6 gleichzeitig, ob die zeitliche Veränderung

• des verbleibenden Energieinhalts des Energiespeichers 2 und/oder
• der Änderungsgeschwindigkeit des Energieinhalts des Energiespeichers 2 und/oder
• einer höheren zeitlichen Ableitung des Energieinhalts des besagten Energiespeichers 2 ,

einer vorgegebenen Funktion folgt. Diese vorgegebene Funktion ist typischerweise abhängig von dem zeitlichen Verlauf des ÖFFNENs oder SCHLIESSENs oder der Änderung des Durchlasswiderstands. Dabei darf der gemessene Wert ein vorgegebenes Toleranzband nicht verlassen. Natürlich kann der Energieinhalt wieder auch in Form einer signifikanten Größe ermittelt werden. Beispielsweise ist es denkbar, nur den Strom in einen Kondensator, der als Energiespeicher dient, hinein oder aus diesem heraus aufzuintegrieren und daraus auf den Ladungszustand zu schließen. Analog könnte auch die Kondensatorspannung gemessen werden. Wie oben kann hieraus wieder ein Messwert für den Zustand des Energiespeichers abgeleitet werden. Auch kann wieder die Regelfunktion des Reglers 6 in Abhängigkeit von der Abweichung von einer solchen Sollfunktion verändert werden. Da diese Informationen für höher geordnete Systeme wichtig sein können, ist es sinnvoll, diese Zustandswerte der Vorrichtung über eine Schnittstelle IF an das höher geordnete System, beispielsweise ein Rechnersystem zu übertragen. Hierbei können beispielsweise

• ∘ ein Regelwert eines der Ausgänge des Reglers,
• ∘ ein interner Regelwert des Reglers,
• ∘ ein Messwert oder Zustandswert eines der Sensoren 26,
• ∘ der Stromwert einer der Strommessstellen 14, 5,
• ∘ der Spannungswert an einem der Knoten 7, 11,
• ∘ die Differenz zwischen Regelwert und Messwert am Regler 6,
• ∘ der Zustand eines oder mehrerer der beteiligten Schaltelemente 3,
• ∘ ein Messwert entsprechend der Spannung über mindestens einem der Schaltelemente 3,
• ∘ ein Messwert entsprechend dem Strom in mindestens einem der Schaltelemente 3

als Werte übertragen werden.Of course, in this case an energy store 2 can be operated in such a way that this device has a measuring device which is able to

• the remaining energy content of the energy storage device 2 and / or
• the rate of change of the energy content of at least the energy storage 2 and / or
• a higher time derivative of the energy content of at least said energy storage 2

to eat. In this case, the device typically has a regulator 6, which typically opens or closes one of the switches 3 or changes its on resistance as a function of at least one of the previously determined values. At the same time, said controller 6 simultaneously checks whether the time change

• the remaining energy content of the energy storage 2 and / or
• the rate of change of the energy content of the energy storage 2 and / or
• a higher time derivative of the energy content of said energy store 2,

follows a given function. This predetermined function is typically dependent on the time course of the OPEN or CLOSE or the change in the on-resistance. The measured value must not leave a specified tolerance band. Of course, the energy content can again be determined in the form of a significant size. For example, it is conceivable to integrate only the current into or out of a capacitor, which serves as an energy store, and to deduce the state of charge. Similarly, the capacitor voltage could be measured. As above, a measured value for the state of the energy store can be derived from this again. Also, the control function of the controller 6 can be changed again depending on the deviation from such a desired function. Since this information can be important for higher-level systems, it makes sense to transmit these state values of the device via an interface IF to the higher-level system, for example a computer system. Here you can for example

• ∘ a control value of one of the outputs of the controller,
• ∘ an internal control value of the controller,
• ∘ a measured value or state value of one of the sensors 26,
• ∘ the current value of one of the current measuring points 14, 5,
• ∘ the voltage value at one of the nodes 7, 11,
• ∘ the difference between the control value and the measured value at the controller 6,
• ∘ the state of one or more of the involved switching elements 3,
• ∘ a measured value corresponding to the voltage across at least one of the switching elements 3,
• ∘ a measured value corresponding to the current in at least one of the switching elements 3

be transmitted as values.

Claims (13)

1. A device comprising

   - at least one first consumer, at least one current source, and with an energy supply unit to supply energy to the at least one first consumer (4), wherein the energy supply unit is provided with

   - at least one energy storage (2),

   - wherein energy can be fed into a first output node (7) by the at least one current source (1) and the at least one energy storage (2),

   - wherein the at least one first consumer (4) can at least temporarily be supplied with energy through this output node (7),

   - wherein the energy storage (2) is designed to supply energy when the energy delivery of the current source (1) is insufficient and the energy storage (2) still has sufficient energy content;

   - at least one switch (3) connected in parallel with the at least one first consumer (4) to bypass and/or cancel a bypass of the first consumer (4) associated with the switch (3); and

   - at least one current and/or current change detection device (5) and/or an energy and/or energy change detection device,

   - wherein the current and/or current change detection device (5) is designed to determine

   a) the current value; and/or

   b) the rate of change in the current; and/or

   c) a higher time derivative of the current value through the aforementioned first consumer (4) or a sequential circuit of multiple first consumers (4), in particular using measurement techniques; and/or

   - wherein the energy and/or energy change detection device (14) is designed to determine

   a) the remaining energy content in the at least one energy storage (2); and/or

   b) the rate of change of the energy content in the at least one energy storage (2); and/or

   c) a higher time derivative of the energy content in the at least one energy storage (2)

   in particular using measurement techniques, wherein the energy content can also be determined by determining a variable representing it; and

   - at least one controller (6) that opens or closes at least one of the switches (3), or changes its conducting-state DC resistance, on the basis of at least one of the previously determined values,

   characterized in that the energy supply unit is designed

   - to reduce, at least temporarily, the mean duration of the closing or the reduction in the conducting-state DC resistance of a switch relative to a time period if the measured current value lies above a specified value I_max2; and/or

   - to reduce, at least temporarily, the mean duration of the closing or reduction in the conducting-state DC resistance of a switch relative to a time period if the amount of the measured rate of change in the current lies above a specified value I_{max_sp2}; and/or

   - to reduce, at least temporarily, the mean duration of the closing or reduction in the conducting-state DC resistance of a switch relative to a time period if the amount of the measured higher time derivative of the current value lies above a specified value I_{max_ac2}; and/or

   - to increase, at least temporarily, the mean duration of the closing or reduction in the conducting-state DC resistance of a switch relative to a time period if the measured current value lies below a specified value I_min2; and/or

   - to increase, at least temporarily, the mean duration of the closing or reduction in the conducting-state DC resistance of a switch relative to a time period if the amount of the measured rate of change in the current lies below a specified value I_{min_sp2}; and/or

   - to increase, at least temporarily, the mean duration of the closing or reduction in the conducting-state DC resistance of a switch relative to a time period, if the amount of the measured higher time derivative of the current value lies below a specified value I_{min_ac2},

   and/or the energy supply unit is designed

   - to lower, at least temporarily, the mean duration of the closing or reduction in the conducting-state DC resistance of a switch relative to a time period if the measured energy content of the energy storage (2) lies below a specified value U_{es_min2}; and/or

   - to lower, at least temporarily, the mean duration of the closing or reduction in the conducting-state DC resistance of a switch relative to a time period if the amount of the measured rate of change in the energy content of the energy storage (2) lies above a specified value U_{es_max_sp2}; and/or

   - to lower, at least temporarily, the mean duration of the closing or reduction in the conducting-state DC resistance of a switch relative to a time period if the amount of the measured higher time derivative of the energy content of the energy storage lies above a specified value U_{es_max_ac2}; and/or

   - to increase, at least temporarily, the mean duration of the closing or reduction in the conducting-state DC resistance of a switch relative to a time period if the measured energy content of the energy storage (2) lies above a specified value U_{es_min3}; and/or

   - to increase, at least temporarily, the mean duration of the closing or reduction in the conducting-state DC resistance of a switch relative to a time period if the amount of the measured rate of change in the energy content lies below a specified value U_{es_max_sp3}; and/or

   - to increase, at least temporarily, the mean duration of the closing or reduction in the conducting-state DC resistance of a switch relative to a time period, if the amount of the measured higher time derivative of the energy content of the energy storage (2) lies below a specified value U_{es_min_ac3}.
2. The device described in claim 1, characterized in that

   - it has more than one first consumer (4) and these first consumers (4) are connected in series; and

   - the first consumers (4) can be supplied by at least a partial current of the current source (1).
3. The device described in claim 1 or 2, characterized in that the energy supply unit is designed

   - not to close any switch or to reduce its conducting-state DC resistance

   a) if the measured current value lies above a specified value I_max1; and/or

   b) if the amount of the measured rate of change in the current lies above a specified value I_{max_sp1},; and/or

   c) if the amount of the measured higher time derivative of the current value lies above a specified value I_{max_ac1}; and/or

   - not to open any switch or to increase its conducting-state DC resistance

   a) if the measured current value lies below a specified value I_min1; and/or

   b) if the amount of the measured rate of change in the current lies below a specified value I_{min_sp1}; and/or

   c) if the amount of the measured higher time derivative of the current value lies below a specified value I_{min_ac1}.
4. The device described in one or more of the preceding claims, characterized in that

   - the at least one switch is a power transistor.
5. The device described in claim 4, characterized in that

   - the power transistor can be controlled by a controller, so that the current value captured by a sensing element during a switching process can be used as at least one controlled variable of this controller and the power transistor is designed to limit the current value to a value smaller than 1.1 or 1.2 or 1.4 times the value that flows through the consumers without a switching process, or double this value.
6. The device described in claim 4 or 5, characterized in that

   - the power transistor can be controlled by a controller, so that the current value captured by a sensing element during a switching process can be used as at least one controlled variable of this controller and the power transistor is designed to limit the current value to a value greater than 0.9 or 0.8 or 0.5 or 0.3 times the value that flows through the consumers without a switching process.
7. The device described in one or more of the preceding claims, characterized in that the energy supply unit is designed

   - to close or reduce the conducting-state DC resistance of at least one first switch simultaneously with the opening or increasing of the conducting-state DC resistance of at least one second switch in order to keep the following within specified or programmed range:

   a) the current value captured by a sensing element; and/or

   b) the rate of change in the current captured by a sensing element; and/or

   c) a higher time derivative of the rate of change in the current captured by a sensing element.
8. The device described in one or more of the preceding claims, characterized in that the energy supply unit is designed

   - not to turn on or off any second switch or change its conducting-state DC resistance during the turning on and/or off or changing the conducting-state DC resistance of at least of one first switch; and/or

   - so that the time interval between the turning on and/or off of at least one first switch or changing of its conducting-state DC resistance and the turning on and/or off of at least one second switch or changing of its conducting-state DC resistance does not to fall below a minimum value t_{min_s}.
9. The device described in one or more of the preceding claims, characterized by

   - a device to supply a circuit of at least three consumers (4)

   - wherein these at least three consumers are connected in at least two parallel series circuits, wherein

   - at least one of these at least two series circuits is a series circuit of at least two consumers (4); and

   - the other series circuit of the at least two series circuits can be a single third consumer (4) or a series circuit of two or more consumers (4),

   - wherein energy can be fed into a first output node (7) by at least one current source (1) and an energy storage (2),

   - wherein the at least three consumers (4) can at least temporarily be supplied with energy through this output node (7), and

   - wherein at least one of the aforementioned at least three consumers (4) has least one switch (3) connected in parallel with it to bypass and/or cancel a bypass of the consumer (4) in question.
10. The device described in claim 9, characterized by

    - at least one device (5) that determines

    a) the current value; and/or

    b) the rate of change in the current; and/or

    c) a higher time derivative of the current value

    through the sequential circuit of the aforementioned consumers (4) of at least one or more or all of the aforementioned at least two series circuits, in particular using measurement techniques.
11. The device described in one or more of the preceding claims, characterized in that

    - it has at least two consumers;

    - and at least one switch associated with each of them, that is a total of at least two such switches;

    - the controller (6) is designed to control the common energy consumption of at least these two consumers so that it corresponds, linearly or nonlinearly, with a value specified by the controller (6) or from outside the system; and

    - the controller (6) is designed to control the relative energy consumption of at least these two consumers, each individually, so that keeping the aforementioned common energy consumption within the permissible tolerances of the application in which the device is being operated does not depend on the individual relative energy consumptions of at least these two consumers.
12. The device described in claim 11, characterized in that the consumers are lamps or light-emitting diodes in one or more luminous colors.
13. The device described in one of the preceding claims, characterized in that the energy supply unit is designed to make the energy conversion dependent, both in its amount and/or in its apportionment to the consumers, on one or more of the following parameters:

    a) a value that is received through an interface or programmed; and/or

    b) the measured value of one or more color sensors; and/or

    c) the measured value of a temperature sensor; and/or

    d) the measured value of another sensor that measures an effect of at least one of the consumers.

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