OSRAM GmbH

In an embodiment an electronic load for installation in a power supply of a vehicle lamp includes a first connection node connected to two first connection sections adapted to be connected between respective corresponding connection sections of a first line carrying a voltage potential, a second connection node connected to two second connection sections adapted to be connected between respective corresponding connection sections of a second line carrying a reference potential, wherein a difference between the voltage potential and the reference potential comprises a supply voltage configured to be supplied to the vehicle lamp and a current sink circuit coupled between the first and second connection nodes, the current sink circuit configured to cause a substantially constant current flow independently of a time-varying supply voltage from at least one of the first connection sections to at least one of the second connection sections.

A method for operating clocked and regulated electronic power converters may be contained in operating devices for light-emitting diodes. An associated regulating circuit may include at least one regulating amplifier having at least two regulating inputs, from the output of which a negative feedback network runs to one of its regulating inputs, a first input for the signal for a target value of the average of the output power to be regulated, and a second input which forwards a signal for the target value of a waveform or of a pulse pattern for the output power to be regulated to one of the regulating inputs via a DC current-blocking high-pass filter.

In an embodiment an electronic load for installation in a power supply of a vehicle lamp includes a first connection node connected to two first connection sections adapted to be connected between respective corresponding connection sections of a first line carrying a voltage potential, a second connection node connected to two second connection sections adapted to be connected between respective corresponding connection sections of a second line carrying a reference potential, wherein a difference between the voltage potential and the reference potential comprises a supply voltage configured to be supplied to the vehicle lamp and a current sink circuit coupled between the first and second connection nodes, the current sink circuit configured to cause a substantially constant current flow independently of a time-varying supply voltage from at least one of the first connection sections to at least one of the second connection sections.

A method for operating clocked and regulated electronic power converters may be contained in operating devices for light-emitting diodes. An associated regulating circuit may include at least one regulating amplifier having at least two regulating inputs, from the output of which a negative feedback network runs to one of its regulating inputs, a first input for the signal for a target value of the average of the output power to be regulated, and a second input which forwards a signal for the target value of a waveform or of a pulse pattern for the output power to be regulated to one of the regulating inputs via a DC current-blocking high-pass filter.

A method for driving a unidirectional current through an electrical load, such as one or more LED modules, by applying thereto a PWM-modulated signal that swings between a high value and a low value envisages choosing said high value and said low value as nonzero values having a same sign.

A circuit arrangement for an LED luminaire comprises a plurality of LED strings, an anode terminal line, a cathode terminal line, a plurality of first switching elements, connected in series into the anode terminal line and subdivided into individual line sections, and a plurality of second switching elements, connected in series into the cathode terminal line and subdivided into individual line sections. Each of the LED strings may be connected to the anode terminal line via a first switching element and/or the second switching elements. Each of the first switching elements may be configured to feed an operating current to an LED string, to electrically connect line sections if the current flowing through the LED string exceeds a predetermined value, and to electrically isolate line sections if the current flowing through the LED string falls below a predetermined value.

A method for driving one or more electrically powered light sources, such as LED modules, may include applying a pulse-width-modulated signal thereto having a pulse-repetition frequency and a duty-cycle, the duty-cycle being selectively variable in order to vary the intensity of light emitted by the light source or light sources. To counter the occurrence of temporal light artefacts, or TLAs, the method may include frequency modulating the pulse-width-modulated signal (V PWM ) by varying the pulse-repetition frequency thereof around a certain value between a lower frequency value and a higher frequency value, thus giving rise to a signal with combined FM/PWM modulation.

A circuit arrangement for operating a load includes a primary-side switched-mode converter with galvanic isolation of input and output voltage, having: a primary circuit, a secondary circuit and a power transformer, wherein: a first inductor and a second inductor, the first inductor being arranged in the secondary circuit in order to pass the current generated by the transformer when the energy is transferred to the secondary circuit, and the second inductor being interconnected in a measuring circuit. The second inductor is spatially arranged in a stray magnetic field generated by the first inductor; the measuring circuit has an output at which a measuring voltage is output, and the control device is connected to the output of the measuring circuit in order to determine a corresponding current flow from the output measuring voltage, and is configured to control the clocked operation of the switch depending on the current flow determined.

A circuit arrangement for an LED luminaire comprises a plurality of LED strings, an anode terminal line, a cathode terminal line, a plurality of first switching elements, connected in series into the anode terminal line and subdivided into individual line sections, and a plurality of second switching elements, connected in series into the cathode terminal line and subdivided into individual line sections. Each of the LED strings may be connected to the anode terminal line via a first switching element and/or the second switching elements. Each of the first switching elements may be configured to feed an operating current to an LED string, to electrically connect line sections if the current flowing through the LED string exceeds a predetermined value, and to electrically isolate line sections if the current flowing through the LED string falls below a predetermined value.

A power supply circuit may include at least a first and a second current generator. Each current generator is implemented with an electronic converter comprising a switching stage, a current sensor generating a feedback signal, and a regulator circuit configured to drive the switching stage as a function of the feedback signal. Specifically, each current sensor is a low-side current sensor configured to generate a feedback signal indicative of the current received via the negative terminal of the respective current generator. The power supply circuit may include also include a control circuit configured for various tasks pertaining to the first and second generators.